‡‡‡ Chapter 12 was amended by 
Local Law 
77 
of 2023
. This law has an effective
date of June 10, 2023.
CHAPTER 12
HYDRONIC PIPING 
SECTION MC 1201
GENERAL
1201.1 Scope. 
The provisions of this chapter shall govern the construction, installation, alteration and repair of hy-
dronic piping systems. This chapter shall apply to hydronic piping systems that are part of heating, ventilation and air
-
conditioning systems. Such piping systems shall include steam, hot water, chilled water, condenser water, cooling 
coil condensate drain, 
steam condensate and ground
-
source heat pump loop systems. Potable cold and hot water dis-
tribution systems shall be installed in accordance with the 
New York City
Plumbing Code
. 
1201.2 Sizing. 
Piping and piping system components for hydronic systems shall be sized for the 
design requirements
of the system.
1201.3 Standards. 
As an alternative to the provisions of Sections 1202 and 1203, piping shall be designed, installed, 
inspected and tested in accordance with ASME B31.
1 and ASME B31.9, as applicable
. 
SECTION 
MC 
1202
MATERIAL
1202.1 Piping. 
Piping material, other than those contained within this section and conforming with the ASTM stand-
ards listed within this chapter, shall be of an approved type.
Exception: 
Embedded piping regulated by Section 1209, and ground
-
source heat pump loop systems regulated by 
Section 1210.
1202.2 Used existing materials. 
Reused pipe, fittings, valves or other materials shall be clean and free of foreign 
materials.
1202.3 Material rating. 
Materials shall be rated for the operating temperature and pressure of the hydronic system. 
Materials shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards. 
Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior 
of the pipe shall be protected from corrosion and d
egradation.
TABLE 1202.4
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene 
(ABS) plastic pipe
ASTM D 1527; ASTM F 2806
Chlorinated polyvinyl chloride 
(CPVC) plastic pipe
ASTM D 2846; ASTM F 441; 
ASTM F 442
Copper, 
brass, or copper
-
alloy 
pipe
ASTM B 42; ASTM B 43; 
ASTM B 302
Copper, brass, or copper
-
alloy 
tube (Type K, L or M)
ASTM B 75; ASTM B 88; 
ASTM B 135; ASTM B 251
HYDRONIC PIPING
Cross
-
linked 
polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe
ASTM F 1281; CSA
B137.10
Cross
-
linked polyethylene 
(PEX) tubing
ASTM F 876; ASTM F 877
Ductile iron pipe
AWWA C115/A21.15; AWWA 
C151/A21.51 
Polyethylene/aluminum/
polyet
hylene 
(PE
-
AL
-
PE) pressure 
pipe
ASTM F 1282; CSA B137.9
Polypropylene (PP) 
plastic pipe
ASTM F 2389
Polyvinyl chloride (PVC) 
plastic pipe
ASTM D 1785; ASTM D 2241
Raised temperature 
polyethylene (PE
-
RT)
ASTM F 2623; ASTM F 2769
Steel pipe
ASTM A 53/A 53M; ASTM A 
106
Steel tubing
ASTM A 254
1202.5 Pipe fittings. 
Hydronic pipe fittings shall conform to the respective pipe standards or to the standards listed in 
Table 1202.5.
TABLE 1202.5
HYDRONIC PIPE FITTINGS
MATERIAL
STANDARD (see Chapter 15)
Copper, brass, and copper 
alloys
ASME B16.15; ASME B16.18; ASME 
B16.22; 
ASME B16.24; 
ASME 
B16.26; 
ASME B16.51; ASTM F 
1974 
Ductile iron and gray iron
ANSI/AWWA C110/A21.10; 
AWWA C153/A21.53; ASTM A 
126; ASTM A 395; ASTM A 536; 
ASTM F 1476; ASTM F 1548
Malleable iron
ASME B16.3
PE
-
RT fittings
ASTM F 1807; ASTM F 2098; 
ASTM F 2159; ASTM F 2735; 
ASTM F 2769
PEX fittings
ASTM F 877; ASTM F 1807; ASTM 
F 2159
Plastic
ASTM D 2466; ASTM D 2467; 
ASTM F 438; ASTM F 439; ASTM 
F
877; ASTM F 2389; ASTM F 2735
HYDRONIC PIPING
Steel
ASME B16.5; ASME 
B16.9; ASME 
B16.11; ASME B16.28; ASTM A 
53/A 53M; ASTM A 106; ASTM A 
234; ASTM A 420; ASTM A 536; 
ASTM A 395; ASTM F 1476; ASTM 
F 1548
1202.6 Valves. 
Valves shall be constructed of materials that are compatible with the type of piping material and fluids 
in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration compensators. 
Flexible connectors, expansion and vibration 
control devices and fit
tings
, when used, shall protect the components of the hydronic system from damage caused by 
expansion, contraction, transverse movement, angular deflection and vibration,
shall be 
rated for the temperatures 
and pressures of the systems in which the devices
are installed, and shall be compatible with the fluid and all materials 
provided
.
SECTION 
MC 
1203
JOINTS AND CONNECTIONS
1203.1 Approval. 
Joints and connections
, other than those contained in Section 1203 and conforming to the ASTM 
standards listed in Sec
tion 1203,
shall be of an approved type. Joints and connections shall be tight for the pressure 
of the hydronic system.
1203.1.1 Joints between different piping materials. 
Joints between different piping materials shall be 
rated for 
the temperatures and pr
essures of the systems in which the devices are installed and shall be compatible with the 
fluid and all materials provided. 
1203.
1.2 Joints between dissimilar metallic piping materials.
Joints between dissimilar metallic piping mate-
rials shall be provide
d to protect against galvanic corrosion. Such joints shall be 
made with 
dielectric fittings 
conforming to ANSI B16.39 or ASTM F 492, as applicable, shall be rated for the temperatures and pressures of 
the systems in which the devices are installed and shal
l be compatible with the fluid and all materials provided
.
Exception:
Dielectric fittings shall not be required for joints between dissimilar metal piping used within heat 
transfer appliances or equipment when such joints are provided by the appliance or e
quipment manufacturer, 
and such appliance or equipment is connected with isolation valves that are accessible.
1203.2 Preparation of pipe ends. 
Pipe shall be cut square, reamed and chamfered, and shall be free of burrs and 
obstructions. Pipe ends shall hav
e full
-
bore openings and shall not be undercut.
1203.3 Joint preparation and installation. 
Where required by Sections 1203.4 through 1203.14, the preparation and 
installation of brazed, mechanical, soldered, 
solvent
-
cemented
, threaded and welded joints shall comply with Sections 
1203.3.1 through 1203.3.8.
1203.3.1 Brazed joints.
All joints 
shall
be brazed with a 
brazing procedure developed and qualified in accordance 
with the ASME
Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications) or in accord-
ance with 
AWS 
B2.2 Standard for Brazing Procedure and Performance Qualifica
tion
.
1203.3.2 Mechanical joints. 
Mechanical joints shall be installed in accordance with the manufacturer’s instruc-
tions.
1203.3.3 Soldered joints. 
Joint surfaces shall be cleaned. A flux conforming to ASTM B 813 shall be applied. The 
joint shall be solde
red with a solder conforming to ASTM B 32.
1203.3.4 Solvent
-
cemented joints. 
Joint surfaces shall be clean and free of moisture. 
A
primer
, compatible with 
both the piping material and the cement
shall be applied to pipe
-
joint surfaces
, in accordance with t
he manufac-
turer’s requirements
. Joints shall be made while the cement is wet. Solvent cement conforming to the following 
standards shall be applied to all joint surfaces:
1.
ASTM D 2235 for ABS joints.
2.
ASTM F 493 for CPVC joints.
‡‡‡ Chapter 12 was amended by 
Local Law 
77 
of 2023
. This law has an effective
date of June 10, 2023.
CHAPTER 12
HYDRONIC PIPING 
SECTION MC 1201
GENERAL
1201.1 Scope. 
The provisions of this chapter shall govern the construction, installation, alteration and repair of hy-
dronic piping systems. This chapter shall apply to hydronic piping systems that are part of heating, ventilation and air
-
conditioning systems. Such piping systems shall include steam, hot water, chilled water, condenser water, cooling 
coil condensate drain, 
steam condensate and ground
-
source heat pump loop systems. Potable cold and hot water dis-
tribution systems shall be installed in accordance with the 
New York City
Plumbing Code
. 
1201.2 Sizing. 
Piping and piping system components for hydronic systems shall be sized for the 
design requirements
of the system.
1201.3 Standards. 
As an alternative to the provisions of Sections 1202 and 1203, piping shall be designed, installed, 
inspected and tested in accordance with ASME B31.
1 and ASME B31.9, as applicable
. 
SECTION 
MC 
1202
MATERIAL
1202.1 Piping. 
Piping material, other than those contained within this section and conforming with the ASTM stand-
ards listed within this chapter, shall be of an approved type.
Exception: 
Embedded piping regulated by Section 1209, and ground
-
source heat pump loop systems regulated by 
Section 1210.
1202.2 Used existing materials. 
Reused pipe, fittings, valves or other materials shall be clean and free of foreign 
materials.
1202.3 Material rating. 
Materials shall be rated for the operating temperature and pressure of the hydronic system. 
Materials shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards. 
Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior 
of the pipe shall be protected from corrosion and d
egradation.
TABLE 1202.4
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene 
(ABS) plastic pipe
ASTM D 1527; ASTM F 2806
Chlorinated polyvinyl chloride 
(CPVC) plastic pipe
ASTM D 2846; ASTM F 441; 
ASTM F 442
Copper, 
brass, or copper
-
alloy 
pipe
ASTM B 42; ASTM B 43; 
ASTM B 302
Copper, brass, or copper
-
alloy 
tube (Type K, L or M)
ASTM B 75; ASTM B 88; 
ASTM B 135; ASTM B 251
HYDRONIC PIPING
Cross
-
linked 
polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe
ASTM F 1281; CSA
B137.10
Cross
-
linked polyethylene 
(PEX) tubing
ASTM F 876; ASTM F 877
Ductile iron pipe
AWWA C115/A21.15; AWWA 
C151/A21.51 
Polyethylene/aluminum/
polyet
hylene 
(PE
-
AL
-
PE) pressure 
pipe
ASTM F 1282; CSA B137.9
Polypropylene (PP) 
plastic pipe
ASTM F 2389
Polyvinyl chloride (PVC) 
plastic pipe
ASTM D 1785; ASTM D 2241
Raised temperature 
polyethylene (PE
-
RT)
ASTM F 2623; ASTM F 2769
Steel pipe
ASTM A 53/A 53M; ASTM A 
106
Steel tubing
ASTM A 254
1202.5 Pipe fittings. 
Hydronic pipe fittings shall conform to the respective pipe standards or to the standards listed in 
Table 1202.5.
TABLE 1202.5
HYDRONIC PIPE FITTINGS
MATERIAL
STANDARD (see Chapter 15)
Copper, brass, and copper 
alloys
ASME B16.15; ASME B16.18; ASME 
B16.22; 
ASME B16.24; 
ASME 
B16.26; 
ASME B16.51; ASTM F 
1974 
Ductile iron and gray iron
ANSI/AWWA C110/A21.10; 
AWWA C153/A21.53; ASTM A 
126; ASTM A 395; ASTM A 536; 
ASTM F 1476; ASTM F 1548
Malleable iron
ASME B16.3
PE
-
RT fittings
ASTM F 1807; ASTM F 2098; 
ASTM F 2159; ASTM F 2735; 
ASTM F 2769
PEX fittings
ASTM F 877; ASTM F 1807; ASTM 
F 2159
Plastic
ASTM D 2466; ASTM D 2467; 
ASTM F 438; ASTM F 439; ASTM 
F
877; ASTM F 2389; ASTM F 2735
HYDRONIC PIPING
Steel
ASME B16.5; ASME 
B16.9; ASME 
B16.11; ASME B16.28; ASTM A 
53/A 53M; ASTM A 106; ASTM A 
234; ASTM A 420; ASTM A 536; 
ASTM A 395; ASTM F 1476; ASTM 
F 1548
1202.6 Valves. 
Valves shall be constructed of materials that are compatible with the type of piping material and fluids 
in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration compensators. 
Flexible connectors, expansion and vibration 
control devices and fit
tings
, when used, shall protect the components of the hydronic system from damage caused by 
expansion, contraction, transverse movement, angular deflection and vibration,
shall be 
rated for the temperatures 
and pressures of the systems in which the devices
are installed, and shall be compatible with the fluid and all materials 
provided
.
SECTION 
MC 
1203
JOINTS AND CONNECTIONS
1203.1 Approval. 
Joints and connections
, other than those contained in Section 1203 and conforming to the ASTM 
standards listed in Sec
tion 1203,
shall be of an approved type. Joints and connections shall be tight for the pressure 
of the hydronic system.
1203.1.1 Joints between different piping materials. 
Joints between different piping materials shall be 
rated for 
the temperatures and pr
essures of the systems in which the devices are installed and shall be compatible with the 
fluid and all materials provided. 
1203.
1.2 Joints between dissimilar metallic piping materials.
Joints between dissimilar metallic piping mate-
rials shall be provide
d to protect against galvanic corrosion. Such joints shall be 
made with 
dielectric fittings 
conforming to ANSI B16.39 or ASTM F 492, as applicable, shall be rated for the temperatures and pressures of 
the systems in which the devices are installed and shal
l be compatible with the fluid and all materials provided
.
Exception:
Dielectric fittings shall not be required for joints between dissimilar metal piping used within heat 
transfer appliances or equipment when such joints are provided by the appliance or e
quipment manufacturer, 
and such appliance or equipment is connected with isolation valves that are accessible.
1203.2 Preparation of pipe ends. 
Pipe shall be cut square, reamed and chamfered, and shall be free of burrs and 
obstructions. Pipe ends shall hav
e full
-
bore openings and shall not be undercut.
1203.3 Joint preparation and installation. 
Where required by Sections 1203.4 through 1203.14, the preparation and 
installation of brazed, mechanical, soldered, 
solvent
-
cemented
, threaded and welded joints shall comply with Sections 
1203.3.1 through 1203.3.8.
1203.3.1 Brazed joints.
All joints 
shall
be brazed with a 
brazing procedure developed and qualified in accordance 
with the ASME
Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications) or in accord-
ance with 
AWS 
B2.2 Standard for Brazing Procedure and Performance Qualifica
tion
.
1203.3.2 Mechanical joints. 
Mechanical joints shall be installed in accordance with the manufacturer’s instruc-
tions.
1203.3.3 Soldered joints. 
Joint surfaces shall be cleaned. A flux conforming to ASTM B 813 shall be applied. The 
joint shall be solde
red with a solder conforming to ASTM B 32.
1203.3.4 Solvent
-
cemented joints. 
Joint surfaces shall be clean and free of moisture. 
A
primer
, compatible with 
both the piping material and the cement
shall be applied to pipe
-
joint surfaces
, in accordance with t
he manufac-
turer’s requirements
. Joints shall be made while the cement is wet. Solvent cement conforming to the following 
standards shall be applied to all joint surfaces:
1.
ASTM D 2235 for ABS joints.
2.
ASTM F 493 for CPVC joints.
‡‡‡ Chapter 12 was amended by 
Local Law 
77 
of 2023
. This law has an effective
date of June 10, 2023.
CHAPTER 12
HYDRONIC PIPING 
SECTION MC 1201
GENERAL
1201.1 Scope. 
The provisions of this chapter shall govern the construction, installation, alteration and repair of hy-
dronic piping systems. This chapter shall apply to hydronic piping systems that are part of heating, ventilation and air
-
conditioning systems. Such piping systems shall include steam, hot water, chilled water, condenser water, cooling 
coil condensate drain, 
steam condensate and ground
-
source heat pump loop systems. Potable cold and hot water dis-
tribution systems shall be installed in accordance with the 
New York City
Plumbing Code
. 
1201.2 Sizing. 
Piping and piping system components for hydronic systems shall be sized for the 
design requirements
of the system.
1201.3 Standards. 
As an alternative to the provisions of Sections 1202 and 1203, piping shall be designed, installed, 
inspected and tested in accordance with ASME B31.
1 and ASME B31.9, as applicable
. 
SECTION 
MC 
1202
MATERIAL
1202.1 Piping. 
Piping material, other than those contained within this section and conforming with the ASTM stand-
ards listed within this chapter, shall be of an approved type.
Exception: 
Embedded piping regulated by Section 1209, and ground
-
source heat pump loop systems regulated by 
Section 1210.
1202.2 Used existing materials. 
Reused pipe, fittings, valves or other materials shall be clean and free of foreign 
materials.
1202.3 Material rating. 
Materials shall be rated for the operating temperature and pressure of the hydronic system. 
Materials shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards. 
Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior 
of the pipe shall be protected from corrosion and d
egradation.
TABLE 1202.4
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene 
(ABS) plastic pipe
ASTM D 1527; ASTM F 2806
Chlorinated polyvinyl chloride 
(CPVC) plastic pipe
ASTM D 2846; ASTM F 441; 
ASTM F 442
Copper, 
brass, or copper
-
alloy 
pipe
ASTM B 42; ASTM B 43; 
ASTM B 302
Copper, brass, or copper
-
alloy 
tube (Type K, L or M)
ASTM B 75; ASTM B 88; 
ASTM B 135; ASTM B 251
HYDRONIC PIPING
Cross
-
linked 
polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe
ASTM F 1281; CSA
B137.10
Cross
-
linked polyethylene 
(PEX) tubing
ASTM F 876; ASTM F 877
Ductile iron pipe
AWWA C115/A21.15; AWWA 
C151/A21.51 
Polyethylene/aluminum/
polyet
hylene 
(PE
-
AL
-
PE) pressure 
pipe
ASTM F 1282; CSA B137.9
Polypropylene (PP) 
plastic pipe
ASTM F 2389
Polyvinyl chloride (PVC) 
plastic pipe
ASTM D 1785; ASTM D 2241
Raised temperature 
polyethylene (PE
-
RT)
ASTM F 2623; ASTM F 2769
Steel pipe
ASTM A 53/A 53M; ASTM A 
106
Steel tubing
ASTM A 254
1202.5 Pipe fittings. 
Hydronic pipe fittings shall conform to the respective pipe standards or to the standards listed in 
Table 1202.5.
TABLE 1202.5
HYDRONIC PIPE FITTINGS
MATERIAL
STANDARD (see Chapter 15)
Copper, brass, and copper 
alloys
ASME B16.15; ASME B16.18; ASME 
B16.22; 
ASME B16.24; 
ASME 
B16.26; 
ASME B16.51; ASTM F 
1974 
Ductile iron and gray iron
ANSI/AWWA C110/A21.10; 
AWWA C153/A21.53; ASTM A 
126; ASTM A 395; ASTM A 536; 
ASTM F 1476; ASTM F 1548
Malleable iron
ASME B16.3
PE
-
RT fittings
ASTM F 1807; ASTM F 2098; 
ASTM F 2159; ASTM F 2735; 
ASTM F 2769
PEX fittings
ASTM F 877; ASTM F 1807; ASTM 
F 2159
Plastic
ASTM D 2466; ASTM D 2467; 
ASTM F 438; ASTM F 439; ASTM 
F
877; ASTM F 2389; ASTM F 2735
HYDRONIC PIPING
Steel
ASME B16.5; ASME 
B16.9; ASME 
B16.11; ASME B16.28; ASTM A 
53/A 53M; ASTM A 106; ASTM A 
234; ASTM A 420; ASTM A 536; 
ASTM A 395; ASTM F 1476; ASTM 
F 1548
1202.6 Valves. 
Valves shall be constructed of materials that are compatible with the type of piping material and fluids 
in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration compensators. 
Flexible connectors, expansion and vibration 
control devices and fit
tings
, when used, shall protect the components of the hydronic system from damage caused by 
expansion, contraction, transverse movement, angular deflection and vibration,
shall be 
rated for the temperatures 
and pressures of the systems in which the devices
are installed, and shall be compatible with the fluid and all materials 
provided
.
SECTION 
MC 
1203
JOINTS AND CONNECTIONS
1203.1 Approval. 
Joints and connections
, other than those contained in Section 1203 and conforming to the ASTM 
standards listed in Sec
tion 1203,
shall be of an approved type. Joints and connections shall be tight for the pressure 
of the hydronic system.
1203.1.1 Joints between different piping materials. 
Joints between different piping materials shall be 
rated for 
the temperatures and pr
essures of the systems in which the devices are installed and shall be compatible with the 
fluid and all materials provided. 
1203.
1.2 Joints between dissimilar metallic piping materials.
Joints between dissimilar metallic piping mate-
rials shall be provide
d to protect against galvanic corrosion. Such joints shall be 
made with 
dielectric fittings 
conforming to ANSI B16.39 or ASTM F 492, as applicable, shall be rated for the temperatures and pressures of 
the systems in which the devices are installed and shal
l be compatible with the fluid and all materials provided
.
Exception:
Dielectric fittings shall not be required for joints between dissimilar metal piping used within heat 
transfer appliances or equipment when such joints are provided by the appliance or e
quipment manufacturer, 
and such appliance or equipment is connected with isolation valves that are accessible.
1203.2 Preparation of pipe ends. 
Pipe shall be cut square, reamed and chamfered, and shall be free of burrs and 
obstructions. Pipe ends shall hav
e full
-
bore openings and shall not be undercut.
1203.3 Joint preparation and installation. 
Where required by Sections 1203.4 through 1203.14, the preparation and 
installation of brazed, mechanical, soldered, 
solvent
-
cemented
, threaded and welded joints shall comply with Sections 
1203.3.1 through 1203.3.8.
1203.3.1 Brazed joints.
All joints 
shall
be brazed with a 
brazing procedure developed and qualified in accordance 
with the ASME
Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications) or in accord-
ance with 
AWS 
B2.2 Standard for Brazing Procedure and Performance Qualifica
tion
.
1203.3.2 Mechanical joints. 
Mechanical joints shall be installed in accordance with the manufacturer’s instruc-
tions.
1203.3.3 Soldered joints. 
Joint surfaces shall be cleaned. A flux conforming to ASTM B 813 shall be applied. The 
joint shall be solde
red with a solder conforming to ASTM B 32.
1203.3.4 Solvent
-
cemented joints. 
Joint surfaces shall be clean and free of moisture. 
A
primer
, compatible with 
both the piping material and the cement
shall be applied to pipe
-
joint surfaces
, in accordance with t
he manufac-
turer’s requirements
. Joints shall be made while the cement is wet. Solvent cement conforming to the following 
standards shall be applied to all joint surfaces:
1.
ASTM D 2235 for ABS joints.
2.
ASTM F 493 for CPVC joints.
HYDRONIC PIPING
3.
ASTM D 2564 for PVC 
joints.
1203.3.5 Threaded joints. 
Threads shall conform to ASME B1.20.1. Schedule 80 or heavier plastic pipe shall be 
threaded with dies specifically designed for plastic pipe. Thread lubricant, pipe
-
joint compound or tape shall be 
applied on the male threads only and shall be 
compatible
f
or application on the piping material
and fluid
.
1203.3.6 Welded joints.
All joints shall be welded with a welding procedure developed and qualified in accord-
ance with the 
ASME Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications
) or in 
accordance with AWS B2.1 Specifications for Welding Procedure and Performance Qualification.
1203.3.7 Grooved and shouldered mechanical joints. 
Grooved and shouldered mechanical joints shall conform 
to the requirements of ASTM F 1476 and shall be i
nstalled in accordance with the manufacturer’s
instructions.
1203.3.8 Mechanically formed tee fittings. 
Mechanically extracted outlets shall have a height not less than three 
times the thickness of the branch tube wall.
1203.3.8.1 Full flow assurance. 
Bran
ch tubes shall not restrict the flow in the run tube. A dimple/depth stop 
shall be formed in the branch tube to ensure that penetration into the outlet is of the correct depth. For inspection 
purposes, a second dimple shall be placed
1
/
4
inch (6.4 mm) above the first dimple. Dimples shall be aligned 
with the tube run.
1203.3.8.2 Brazed joints. 
Mechanically formed tee fittings shall be brazed in accordance with Section 1203.3.1.
1203.4 ABS plastic pipe. 
Joints between ABS plastic pipe or f
ittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.5 Brass pipe. 
Joints between brass pipe or fittings shall be brazed, mechanical, threaded or welded joints con-
forming to Section 1203.3.
1203.6 Brass tubing. 
Joints bet
ween brass tubing or fittings shall be brazed, mechanical or soldered joints conforming 
to Section 1203.3.
1203.7 Copper or copper
-
alloy pipe. 
Joints between copper or copper
-
alloy pipe or fittings shall be brazed, mechan-
ical, soldered, threaded or welded 
joints conforming to Section 1203.3.
1203.8 Copper or copper
-
alloy tubing. 
Joints between copper or copper
-
alloy tubing or fittings shall be brazed, 
mechanical or soldered joints conforming to Section 1203.3, flared joints conforming to Section 1203.8.1
or
push
-
fit 
joints conforming to Section 1203.8.2.
1203.8.1 Flared joints. 
Flared joints shall be made by a tool designed for that operation.
1203.8.2 Push
-
fit joints. 
Push
-
fit joints shall be installed in accordance with the manufacturer’s instructions.
120
3.9 CPVC plastic pipe.   
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.10 Reserved.
1203.11 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints between cross
-
linked polyethyle
ne plastic tubing 
and fittings shall conform to Sections 1203.11.1 and 1203.11.2. Mechanical joints shall conform to Section 1203.3.
1203.11.1 Compression
-
type fittings. 
Where
compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings 
shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.11.2 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not less 
than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same 
water line.
1203.12 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.13 Steel pipe. 
Joints between steel pipe or fittings shall be mechanical
, threaded or welded 
joints 
conforming to 
Section 1203.3.
1203.14 Steel tubing. 
Joints between steel tubing or fittings shall be mechanical or welded joints conforming to Sec-
tion 1203.3.
HYDRONIC PIPING
1203.15 Polypropylene (PP) plastic. 
Joints between PP plastic pipe and fittings shall comp
ly with Sections 1203.15.1 
and 1203.15.2.
1203.15.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylene fittings, electro
-
fusion polypropylene fittings or by butt
fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1203.15.2 Mechanical and compression sleeve joints. 
Mechanical and compression sleeve joints shal
l be installed 
in accordance with the manufacturer’s instructions.
1203.16 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyethylene 
tubing and fittings shall conform to Sections 1203.16.1 and 1203.16.2. Mechani
cal joints shall conform to Section 
1203.3.
1203.16.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.16.2 PE
-
RT
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 mm) 
of a transition from such metal pipe to PE
-
RT pipe.
1203.17 Polyethylene/aluminum/polyethylene (PE
-
AL
-
PE) pressure pipe. 
Joints between polyethylene/alumi-
num/po
lyethylene pressure pipe and fittings shall conform to Sections 1203.17.1 and 1203.17.2. Mechanical joints 
shall comply with Section 1203.3.
1203.17.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
f
ittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.17.2 PE
-
AL
-
PE
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 
mm) of a transition from such metal pipe to PE
-
AL
-
PE pipe.
1203.18 Cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe. 
Joints 
between cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene pressure pipe and fittings shall conform to 
Sections 1203.18.1 and 1203.18.2. Mecha
nical joints shall comply with Section 1203.3.
1203.18.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.18.2 PEX
-
AL
-
PEX
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches 
(457.2 mm) of a transition from such metal pipe to PEX
-
AL
-
PEX pipe.
SECTION 
MC 
1204
PIPE INSULATION
1204.1 Insulation characteristics. 
Pipe insulation installed in buildings shall conform to the requirements of the 
New 
York City
Energy Conservation Code
,
shall be tested in accordance with ASTM E 84 or UL 723, using the specimen 
preparation and mounting p
rocedures of ASTM E 2231; and shall have a maximum flame spread index of 25 and a 
smoke
-
developed index not exceeding 450. Insulation installed in an air plenum shall comply with Section 602.2.1.
1204.2 Required thickness. 
Hydronic piping shall be insulate
d to the thickness required by the 
New York City
Energy 
Conservation Code.
SECTION 
MC 
1205
VALVES
1205.1 Where required. 
Shutoff valves shall be installed in hydronic piping systems in the locations indicated in 
Sections 1205.1.1 through 1205.1.6.
1205.1.1
Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
‡‡‡ Chapter 12 was amended by 
Local Law 
77 
of 2023
. This law has an effective
date of June 10, 2023.
CHAPTER 12
HYDRONIC PIPING 
SECTION MC 1201
GENERAL
1201.1 Scope. 
The provisions of this chapter shall govern the construction, installation, alteration and repair of hy-
dronic piping systems. This chapter shall apply to hydronic piping systems that are part of heating, ventilation and air
-
conditioning systems. Such piping systems shall include steam, hot water, chilled water, condenser water, cooling 
coil condensate drain, 
steam condensate and ground
-
source heat pump loop systems. Potable cold and hot water dis-
tribution systems shall be installed in accordance with the 
New York City
Plumbing Code
. 
1201.2 Sizing. 
Piping and piping system components for hydronic systems shall be sized for the 
design requirements
of the system.
1201.3 Standards. 
As an alternative to the provisions of Sections 1202 and 1203, piping shall be designed, installed, 
inspected and tested in accordance with ASME B31.
1 and ASME B31.9, as applicable
. 
SECTION 
MC 
1202
MATERIAL
1202.1 Piping. 
Piping material, other than those contained within this section and conforming with the ASTM stand-
ards listed within this chapter, shall be of an approved type.
Exception: 
Embedded piping regulated by Section 1209, and ground
-
source heat pump loop systems regulated by 
Section 1210.
1202.2 Used existing materials. 
Reused pipe, fittings, valves or other materials shall be clean and free of foreign 
materials.
1202.3 Material rating. 
Materials shall be rated for the operating temperature and pressure of the hydronic system. 
Materials shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards. 
Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior 
of the pipe shall be protected from corrosion and d
egradation.
TABLE 1202.4
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene 
(ABS) plastic pipe
ASTM D 1527; ASTM F 2806
Chlorinated polyvinyl chloride 
(CPVC) plastic pipe
ASTM D 2846; ASTM F 441; 
ASTM F 442
Copper, 
brass, or copper
-
alloy 
pipe
ASTM B 42; ASTM B 43; 
ASTM B 302
Copper, brass, or copper
-
alloy 
tube (Type K, L or M)
ASTM B 75; ASTM B 88; 
ASTM B 135; ASTM B 251
HYDRONIC PIPING
Cross
-
linked 
polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe
ASTM F 1281; CSA
B137.10
Cross
-
linked polyethylene 
(PEX) tubing
ASTM F 876; ASTM F 877
Ductile iron pipe
AWWA C115/A21.15; AWWA 
C151/A21.51 
Polyethylene/aluminum/
polyet
hylene 
(PE
-
AL
-
PE) pressure 
pipe
ASTM F 1282; CSA B137.9
Polypropylene (PP) 
plastic pipe
ASTM F 2389
Polyvinyl chloride (PVC) 
plastic pipe
ASTM D 1785; ASTM D 2241
Raised temperature 
polyethylene (PE
-
RT)
ASTM F 2623; ASTM F 2769
Steel pipe
ASTM A 53/A 53M; ASTM A 
106
Steel tubing
ASTM A 254
1202.5 Pipe fittings. 
Hydronic pipe fittings shall conform to the respective pipe standards or to the standards listed in 
Table 1202.5.
TABLE 1202.5
HYDRONIC PIPE FITTINGS
MATERIAL
STANDARD (see Chapter 15)
Copper, brass, and copper 
alloys
ASME B16.15; ASME B16.18; ASME 
B16.22; 
ASME B16.24; 
ASME 
B16.26; 
ASME B16.51; ASTM F 
1974 
Ductile iron and gray iron
ANSI/AWWA C110/A21.10; 
AWWA C153/A21.53; ASTM A 
126; ASTM A 395; ASTM A 536; 
ASTM F 1476; ASTM F 1548
Malleable iron
ASME B16.3
PE
-
RT fittings
ASTM F 1807; ASTM F 2098; 
ASTM F 2159; ASTM F 2735; 
ASTM F 2769
PEX fittings
ASTM F 877; ASTM F 1807; ASTM 
F 2159
Plastic
ASTM D 2466; ASTM D 2467; 
ASTM F 438; ASTM F 439; ASTM 
F
877; ASTM F 2389; ASTM F 2735
HYDRONIC PIPING
Steel
ASME B16.5; ASME 
B16.9; ASME 
B16.11; ASME B16.28; ASTM A 
53/A 53M; ASTM A 106; ASTM A 
234; ASTM A 420; ASTM A 536; 
ASTM A 395; ASTM F 1476; ASTM 
F 1548
1202.6 Valves. 
Valves shall be constructed of materials that are compatible with the type of piping material and fluids 
in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration compensators. 
Flexible connectors, expansion and vibration 
control devices and fit
tings
, when used, shall protect the components of the hydronic system from damage caused by 
expansion, contraction, transverse movement, angular deflection and vibration,
shall be 
rated for the temperatures 
and pressures of the systems in which the devices
are installed, and shall be compatible with the fluid and all materials 
provided
.
SECTION 
MC 
1203
JOINTS AND CONNECTIONS
1203.1 Approval. 
Joints and connections
, other than those contained in Section 1203 and conforming to the ASTM 
standards listed in Sec
tion 1203,
shall be of an approved type. Joints and connections shall be tight for the pressure 
of the hydronic system.
1203.1.1 Joints between different piping materials. 
Joints between different piping materials shall be 
rated for 
the temperatures and pr
essures of the systems in which the devices are installed and shall be compatible with the 
fluid and all materials provided. 
1203.
1.2 Joints between dissimilar metallic piping materials.
Joints between dissimilar metallic piping mate-
rials shall be provide
d to protect against galvanic corrosion. Such joints shall be 
made with 
dielectric fittings 
conforming to ANSI B16.39 or ASTM F 492, as applicable, shall be rated for the temperatures and pressures of 
the systems in which the devices are installed and shal
l be compatible with the fluid and all materials provided
.
Exception:
Dielectric fittings shall not be required for joints between dissimilar metal piping used within heat 
transfer appliances or equipment when such joints are provided by the appliance or e
quipment manufacturer, 
and such appliance or equipment is connected with isolation valves that are accessible.
1203.2 Preparation of pipe ends. 
Pipe shall be cut square, reamed and chamfered, and shall be free of burrs and 
obstructions. Pipe ends shall hav
e full
-
bore openings and shall not be undercut.
1203.3 Joint preparation and installation. 
Where required by Sections 1203.4 through 1203.14, the preparation and 
installation of brazed, mechanical, soldered, 
solvent
-
cemented
, threaded and welded joints shall comply with Sections 
1203.3.1 through 1203.3.8.
1203.3.1 Brazed joints.
All joints 
shall
be brazed with a 
brazing procedure developed and qualified in accordance 
with the ASME
Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications) or in accord-
ance with 
AWS 
B2.2 Standard for Brazing Procedure and Performance Qualifica
tion
.
1203.3.2 Mechanical joints. 
Mechanical joints shall be installed in accordance with the manufacturer’s instruc-
tions.
1203.3.3 Soldered joints. 
Joint surfaces shall be cleaned. A flux conforming to ASTM B 813 shall be applied. The 
joint shall be solde
red with a solder conforming to ASTM B 32.
1203.3.4 Solvent
-
cemented joints. 
Joint surfaces shall be clean and free of moisture. 
A
primer
, compatible with 
both the piping material and the cement
shall be applied to pipe
-
joint surfaces
, in accordance with t
he manufac-
turer’s requirements
. Joints shall be made while the cement is wet. Solvent cement conforming to the following 
standards shall be applied to all joint surfaces:
1.
ASTM D 2235 for ABS joints.
2.
ASTM F 493 for CPVC joints.
HYDRONIC PIPING
3.
ASTM D 2564 for PVC 
joints.
1203.3.5 Threaded joints. 
Threads shall conform to ASME B1.20.1. Schedule 80 or heavier plastic pipe shall be 
threaded with dies specifically designed for plastic pipe. Thread lubricant, pipe
-
joint compound or tape shall be 
applied on the male threads only and shall be 
compatible
f
or application on the piping material
and fluid
.
1203.3.6 Welded joints.
All joints shall be welded with a welding procedure developed and qualified in accord-
ance with the 
ASME Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications
) or in 
accordance with AWS B2.1 Specifications for Welding Procedure and Performance Qualification.
1203.3.7 Grooved and shouldered mechanical joints. 
Grooved and shouldered mechanical joints shall conform 
to the requirements of ASTM F 1476 and shall be i
nstalled in accordance with the manufacturer’s
instructions.
1203.3.8 Mechanically formed tee fittings. 
Mechanically extracted outlets shall have a height not less than three 
times the thickness of the branch tube wall.
1203.3.8.1 Full flow assurance. 
Bran
ch tubes shall not restrict the flow in the run tube. A dimple/depth stop 
shall be formed in the branch tube to ensure that penetration into the outlet is of the correct depth. For inspection 
purposes, a second dimple shall be placed
1
/
4
inch (6.4 mm) above the first dimple. Dimples shall be aligned 
with the tube run.
1203.3.8.2 Brazed joints. 
Mechanically formed tee fittings shall be brazed in accordance with Section 1203.3.1.
1203.4 ABS plastic pipe. 
Joints between ABS plastic pipe or f
ittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.5 Brass pipe. 
Joints between brass pipe or fittings shall be brazed, mechanical, threaded or welded joints con-
forming to Section 1203.3.
1203.6 Brass tubing. 
Joints bet
ween brass tubing or fittings shall be brazed, mechanical or soldered joints conforming 
to Section 1203.3.
1203.7 Copper or copper
-
alloy pipe. 
Joints between copper or copper
-
alloy pipe or fittings shall be brazed, mechan-
ical, soldered, threaded or welded 
joints conforming to Section 1203.3.
1203.8 Copper or copper
-
alloy tubing. 
Joints between copper or copper
-
alloy tubing or fittings shall be brazed, 
mechanical or soldered joints conforming to Section 1203.3, flared joints conforming to Section 1203.8.1
or
push
-
fit 
joints conforming to Section 1203.8.2.
1203.8.1 Flared joints. 
Flared joints shall be made by a tool designed for that operation.
1203.8.2 Push
-
fit joints. 
Push
-
fit joints shall be installed in accordance with the manufacturer’s instructions.
120
3.9 CPVC plastic pipe.   
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.10 Reserved.
1203.11 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints between cross
-
linked polyethyle
ne plastic tubing 
and fittings shall conform to Sections 1203.11.1 and 1203.11.2. Mechanical joints shall conform to Section 1203.3.
1203.11.1 Compression
-
type fittings. 
Where
compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings 
shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.11.2 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not less 
than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same 
water line.
1203.12 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.13 Steel pipe. 
Joints between steel pipe or fittings shall be mechanical
, threaded or welded 
joints 
conforming to 
Section 1203.3.
1203.14 Steel tubing. 
Joints between steel tubing or fittings shall be mechanical or welded joints conforming to Sec-
tion 1203.3.
HYDRONIC PIPING
1203.15 Polypropylene (PP) plastic. 
Joints between PP plastic pipe and fittings shall comp
ly with Sections 1203.15.1 
and 1203.15.2.
1203.15.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylene fittings, electro
-
fusion polypropylene fittings or by butt
fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1203.15.2 Mechanical and compression sleeve joints. 
Mechanical and compression sleeve joints shal
l be installed 
in accordance with the manufacturer’s instructions.
1203.16 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyethylene 
tubing and fittings shall conform to Sections 1203.16.1 and 1203.16.2. Mechani
cal joints shall conform to Section 
1203.3.
1203.16.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.16.2 PE
-
RT
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 mm) 
of a transition from such metal pipe to PE
-
RT pipe.
1203.17 Polyethylene/aluminum/polyethylene (PE
-
AL
-
PE) pressure pipe. 
Joints between polyethylene/alumi-
num/po
lyethylene pressure pipe and fittings shall conform to Sections 1203.17.1 and 1203.17.2. Mechanical joints 
shall comply with Section 1203.3.
1203.17.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
f
ittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.17.2 PE
-
AL
-
PE
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 
mm) of a transition from such metal pipe to PE
-
AL
-
PE pipe.
1203.18 Cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe. 
Joints 
between cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene pressure pipe and fittings shall conform to 
Sections 1203.18.1 and 1203.18.2. Mecha
nical joints shall comply with Section 1203.3.
1203.18.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.18.2 PEX
-
AL
-
PEX
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches 
(457.2 mm) of a transition from such metal pipe to PEX
-
AL
-
PEX pipe.
SECTION 
MC 
1204
PIPE INSULATION
1204.1 Insulation characteristics. 
Pipe insulation installed in buildings shall conform to the requirements of the 
New 
York City
Energy Conservation Code
,
shall be tested in accordance with ASTM E 84 or UL 723, using the specimen 
preparation and mounting p
rocedures of ASTM E 2231; and shall have a maximum flame spread index of 25 and a 
smoke
-
developed index not exceeding 450. Insulation installed in an air plenum shall comply with Section 602.2.1.
1204.2 Required thickness. 
Hydronic piping shall be insulate
d to the thickness required by the 
New York City
Energy 
Conservation Code.
SECTION 
MC 
1205
VALVES
1205.1 Where required. 
Shutoff valves shall be installed in hydronic piping systems in the locations indicated in 
Sections 1205.1.1 through 1205.1.6.
1205.1.1
Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
HYDRONIC PIPING
Exception: 
Shutoff valves shall not be required where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat 
exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1205.1.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of central utility 
systems, and district
heating and cooling 
systems.
1205.1.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1205.1.4 Pressure
-
reducing valves. 
Shutoff valves shall be installed on both sides of a pressure
-
reduc
ing valve.
1205.1.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a hydronic system such as pumps, air separators, 
metering devices and si
milar equipment.
1205.1.6 Expansion tanks.
Lockable shutoff
valves shall be installed at connections to 
all
expansion tanks.
Valves shall be locked in the open position.
1205.2 Reduced pressure. 
A pressure relief valve shall be installed on the 
low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system design. 
The valve shall be installed in accordance with Section 1006.
SECTION 
MC 
1206
PIPING INSTALLATION
1
206.1 General. 
Piping, valves, fittings and connections shall be installed in accordance with the conditions of ap-
proval.
1206.2 System drain down. 
Hydronic piping systems shall be designed and installed to permit the system to be 
drained. Where the system
drains to the plumbing drainage system, the installation shall conform to the requirements 
of the 
New York City
Plumbing Code.
Exception: 
The buried portions of systems embedded underground.
1206.3 Protection of potable water. 
The potable water system sha
ll be protected from backflow in accordance with 
the 
New York City
Plumbing Code.
1206.4 Pipe penetrations. 
Openings for pipe penetrations in walls, floors or ceilings shall be larger than the penetrat-
ing pipe. Openings through concrete or masonry building
elements shall be sleeved. The annular space surrounding 
pipe penetrations shall be protected in accordance with the 
New York City
Building Code.
1206.5 Clearance to combustibles. 
A pipe in a hydronic piping system in which the exterior temperature exceed
s 
250°F (
121.1
°C) shall have a minimum clearance of 1 inch (25.4 mm) to combustible materials.
1206.6 Contact with building material. 
A hydronic piping system shall not be in direct contact with building mate-
rials that cause the piping material to degrade 
or corrode, or that interfere with the operation of the system.
1206.7 Water hammer. 
The flow velocity of the hydronic piping system shall be controlled to reduce the possibility 
of water hammer. Where a quick
-
closing valve creates water hammer, an 
enginee
red
water
-
hammer arrestor shall be 
installed. The arrestor shall be located within a range as specified by the manufacturer of the quick
-
closing valve.
1206.8 Steam piping pitch. 
Steam piping shall be installed to drain to the boiler or the steam trap. Ste
am systems 
shall not have drip pockets that reduce the capacity of the steam piping.
1206.9 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains and stresses in the pipe. 
Provisions shall be made to protect piping from damag
e resulting from expansion, contraction and structural settle-
ment. Piping shall be installed so as to avoid structural stresses or strains within building components.
1206.9.1 Flood hazard. 
Piping located in flood hazard areas 
shall comply with Appendix G
of 
the 
New York City 
Building Code
.
‡‡‡ Chapter 12 was amended by 
Local Law 
77 
of 2023
. This law has an effective
date of June 10, 2023.
CHAPTER 12
HYDRONIC PIPING 
SECTION MC 1201
GENERAL
1201.1 Scope. 
The provisions of this chapter shall govern the construction, installation, alteration and repair of hy-
dronic piping systems. This chapter shall apply to hydronic piping systems that are part of heating, ventilation and air
-
conditioning systems. Such piping systems shall include steam, hot water, chilled water, condenser water, cooling 
coil condensate drain, 
steam condensate and ground
-
source heat pump loop systems. Potable cold and hot water dis-
tribution systems shall be installed in accordance with the 
New York City
Plumbing Code
. 
1201.2 Sizing. 
Piping and piping system components for hydronic systems shall be sized for the 
design requirements
of the system.
1201.3 Standards. 
As an alternative to the provisions of Sections 1202 and 1203, piping shall be designed, installed, 
inspected and tested in accordance with ASME B31.
1 and ASME B31.9, as applicable
. 
SECTION 
MC 
1202
MATERIAL
1202.1 Piping. 
Piping material, other than those contained within this section and conforming with the ASTM stand-
ards listed within this chapter, shall be of an approved type.
Exception: 
Embedded piping regulated by Section 1209, and ground
-
source heat pump loop systems regulated by 
Section 1210.
1202.2 Used existing materials. 
Reused pipe, fittings, valves or other materials shall be clean and free of foreign 
materials.
1202.3 Material rating. 
Materials shall be rated for the operating temperature and pressure of the hydronic system. 
Materials shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards. 
Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior 
of the pipe shall be protected from corrosion and d
egradation.
TABLE 1202.4
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene 
(ABS) plastic pipe
ASTM D 1527; ASTM F 2806
Chlorinated polyvinyl chloride 
(CPVC) plastic pipe
ASTM D 2846; ASTM F 441; 
ASTM F 442
Copper, 
brass, or copper
-
alloy 
pipe
ASTM B 42; ASTM B 43; 
ASTM B 302
Copper, brass, or copper
-
alloy 
tube (Type K, L or M)
ASTM B 75; ASTM B 88; 
ASTM B 135; ASTM B 251
HYDRONIC PIPING
Cross
-
linked 
polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe
ASTM F 1281; CSA
B137.10
Cross
-
linked polyethylene 
(PEX) tubing
ASTM F 876; ASTM F 877
Ductile iron pipe
AWWA C115/A21.15; AWWA 
C151/A21.51 
Polyethylene/aluminum/
polyet
hylene 
(PE
-
AL
-
PE) pressure 
pipe
ASTM F 1282; CSA B137.9
Polypropylene (PP) 
plastic pipe
ASTM F 2389
Polyvinyl chloride (PVC) 
plastic pipe
ASTM D 1785; ASTM D 2241
Raised temperature 
polyethylene (PE
-
RT)
ASTM F 2623; ASTM F 2769
Steel pipe
ASTM A 53/A 53M; ASTM A 
106
Steel tubing
ASTM A 254
1202.5 Pipe fittings. 
Hydronic pipe fittings shall conform to the respective pipe standards or to the standards listed in 
Table 1202.5.
TABLE 1202.5
HYDRONIC PIPE FITTINGS
MATERIAL
STANDARD (see Chapter 15)
Copper, brass, and copper 
alloys
ASME B16.15; ASME B16.18; ASME 
B16.22; 
ASME B16.24; 
ASME 
B16.26; 
ASME B16.51; ASTM F 
1974 
Ductile iron and gray iron
ANSI/AWWA C110/A21.10; 
AWWA C153/A21.53; ASTM A 
126; ASTM A 395; ASTM A 536; 
ASTM F 1476; ASTM F 1548
Malleable iron
ASME B16.3
PE
-
RT fittings
ASTM F 1807; ASTM F 2098; 
ASTM F 2159; ASTM F 2735; 
ASTM F 2769
PEX fittings
ASTM F 877; ASTM F 1807; ASTM 
F 2159
Plastic
ASTM D 2466; ASTM D 2467; 
ASTM F 438; ASTM F 439; ASTM 
F
877; ASTM F 2389; ASTM F 2735
HYDRONIC PIPING
Steel
ASME B16.5; ASME 
B16.9; ASME 
B16.11; ASME B16.28; ASTM A 
53/A 53M; ASTM A 106; ASTM A 
234; ASTM A 420; ASTM A 536; 
ASTM A 395; ASTM F 1476; ASTM 
F 1548
1202.6 Valves. 
Valves shall be constructed of materials that are compatible with the type of piping material and fluids 
in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration compensators. 
Flexible connectors, expansion and vibration 
control devices and fit
tings
, when used, shall protect the components of the hydronic system from damage caused by 
expansion, contraction, transverse movement, angular deflection and vibration,
shall be 
rated for the temperatures 
and pressures of the systems in which the devices
are installed, and shall be compatible with the fluid and all materials 
provided
.
SECTION 
MC 
1203
JOINTS AND CONNECTIONS
1203.1 Approval. 
Joints and connections
, other than those contained in Section 1203 and conforming to the ASTM 
standards listed in Sec
tion 1203,
shall be of an approved type. Joints and connections shall be tight for the pressure 
of the hydronic system.
1203.1.1 Joints between different piping materials. 
Joints between different piping materials shall be 
rated for 
the temperatures and pr
essures of the systems in which the devices are installed and shall be compatible with the 
fluid and all materials provided. 
1203.
1.2 Joints between dissimilar metallic piping materials.
Joints between dissimilar metallic piping mate-
rials shall be provide
d to protect against galvanic corrosion. Such joints shall be 
made with 
dielectric fittings 
conforming to ANSI B16.39 or ASTM F 492, as applicable, shall be rated for the temperatures and pressures of 
the systems in which the devices are installed and shal
l be compatible with the fluid and all materials provided
.
Exception:
Dielectric fittings shall not be required for joints between dissimilar metal piping used within heat 
transfer appliances or equipment when such joints are provided by the appliance or e
quipment manufacturer, 
and such appliance or equipment is connected with isolation valves that are accessible.
1203.2 Preparation of pipe ends. 
Pipe shall be cut square, reamed and chamfered, and shall be free of burrs and 
obstructions. Pipe ends shall hav
e full
-
bore openings and shall not be undercut.
1203.3 Joint preparation and installation. 
Where required by Sections 1203.4 through 1203.14, the preparation and 
installation of brazed, mechanical, soldered, 
solvent
-
cemented
, threaded and welded joints shall comply with Sections 
1203.3.1 through 1203.3.8.
1203.3.1 Brazed joints.
All joints 
shall
be brazed with a 
brazing procedure developed and qualified in accordance 
with the ASME
Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications) or in accord-
ance with 
AWS 
B2.2 Standard for Brazing Procedure and Performance Qualifica
tion
.
1203.3.2 Mechanical joints. 
Mechanical joints shall be installed in accordance with the manufacturer’s instruc-
tions.
1203.3.3 Soldered joints. 
Joint surfaces shall be cleaned. A flux conforming to ASTM B 813 shall be applied. The 
joint shall be solde
red with a solder conforming to ASTM B 32.
1203.3.4 Solvent
-
cemented joints. 
Joint surfaces shall be clean and free of moisture. 
A
primer
, compatible with 
both the piping material and the cement
shall be applied to pipe
-
joint surfaces
, in accordance with t
he manufac-
turer’s requirements
. Joints shall be made while the cement is wet. Solvent cement conforming to the following 
standards shall be applied to all joint surfaces:
1.
ASTM D 2235 for ABS joints.
2.
ASTM F 493 for CPVC joints.
HYDRONIC PIPING
3.
ASTM D 2564 for PVC 
joints.
1203.3.5 Threaded joints. 
Threads shall conform to ASME B1.20.1. Schedule 80 or heavier plastic pipe shall be 
threaded with dies specifically designed for plastic pipe. Thread lubricant, pipe
-
joint compound or tape shall be 
applied on the male threads only and shall be 
compatible
f
or application on the piping material
and fluid
.
1203.3.6 Welded joints.
All joints shall be welded with a welding procedure developed and qualified in accord-
ance with the 
ASME Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications
) or in 
accordance with AWS B2.1 Specifications for Welding Procedure and Performance Qualification.
1203.3.7 Grooved and shouldered mechanical joints. 
Grooved and shouldered mechanical joints shall conform 
to the requirements of ASTM F 1476 and shall be i
nstalled in accordance with the manufacturer’s
instructions.
1203.3.8 Mechanically formed tee fittings. 
Mechanically extracted outlets shall have a height not less than three 
times the thickness of the branch tube wall.
1203.3.8.1 Full flow assurance. 
Bran
ch tubes shall not restrict the flow in the run tube. A dimple/depth stop 
shall be formed in the branch tube to ensure that penetration into the outlet is of the correct depth. For inspection 
purposes, a second dimple shall be placed
1
/
4
inch (6.4 mm) above the first dimple. Dimples shall be aligned 
with the tube run.
1203.3.8.2 Brazed joints. 
Mechanically formed tee fittings shall be brazed in accordance with Section 1203.3.1.
1203.4 ABS plastic pipe. 
Joints between ABS plastic pipe or f
ittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.5 Brass pipe. 
Joints between brass pipe or fittings shall be brazed, mechanical, threaded or welded joints con-
forming to Section 1203.3.
1203.6 Brass tubing. 
Joints bet
ween brass tubing or fittings shall be brazed, mechanical or soldered joints conforming 
to Section 1203.3.
1203.7 Copper or copper
-
alloy pipe. 
Joints between copper or copper
-
alloy pipe or fittings shall be brazed, mechan-
ical, soldered, threaded or welded 
joints conforming to Section 1203.3.
1203.8 Copper or copper
-
alloy tubing. 
Joints between copper or copper
-
alloy tubing or fittings shall be brazed, 
mechanical or soldered joints conforming to Section 1203.3, flared joints conforming to Section 1203.8.1
or
push
-
fit 
joints conforming to Section 1203.8.2.
1203.8.1 Flared joints. 
Flared joints shall be made by a tool designed for that operation.
1203.8.2 Push
-
fit joints. 
Push
-
fit joints shall be installed in accordance with the manufacturer’s instructions.
120
3.9 CPVC plastic pipe.   
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.10 Reserved.
1203.11 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints between cross
-
linked polyethyle
ne plastic tubing 
and fittings shall conform to Sections 1203.11.1 and 1203.11.2. Mechanical joints shall conform to Section 1203.3.
1203.11.1 Compression
-
type fittings. 
Where
compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings 
shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.11.2 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not less 
than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same 
water line.
1203.12 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.13 Steel pipe. 
Joints between steel pipe or fittings shall be mechanical
, threaded or welded 
joints 
conforming to 
Section 1203.3.
1203.14 Steel tubing. 
Joints between steel tubing or fittings shall be mechanical or welded joints conforming to Sec-
tion 1203.3.
HYDRONIC PIPING
1203.15 Polypropylene (PP) plastic. 
Joints between PP plastic pipe and fittings shall comp
ly with Sections 1203.15.1 
and 1203.15.2.
1203.15.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylene fittings, electro
-
fusion polypropylene fittings or by butt
fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1203.15.2 Mechanical and compression sleeve joints. 
Mechanical and compression sleeve joints shal
l be installed 
in accordance with the manufacturer’s instructions.
1203.16 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyethylene 
tubing and fittings shall conform to Sections 1203.16.1 and 1203.16.2. Mechani
cal joints shall conform to Section 
1203.3.
1203.16.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.16.2 PE
-
RT
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 mm) 
of a transition from such metal pipe to PE
-
RT pipe.
1203.17 Polyethylene/aluminum/polyethylene (PE
-
AL
-
PE) pressure pipe. 
Joints between polyethylene/alumi-
num/po
lyethylene pressure pipe and fittings shall conform to Sections 1203.17.1 and 1203.17.2. Mechanical joints 
shall comply with Section 1203.3.
1203.17.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
f
ittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.17.2 PE
-
AL
-
PE
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 
mm) of a transition from such metal pipe to PE
-
AL
-
PE pipe.
1203.18 Cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe. 
Joints 
between cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene pressure pipe and fittings shall conform to 
Sections 1203.18.1 and 1203.18.2. Mecha
nical joints shall comply with Section 1203.3.
1203.18.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.18.2 PEX
-
AL
-
PEX
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches 
(457.2 mm) of a transition from such metal pipe to PEX
-
AL
-
PEX pipe.
SECTION 
MC 
1204
PIPE INSULATION
1204.1 Insulation characteristics. 
Pipe insulation installed in buildings shall conform to the requirements of the 
New 
York City
Energy Conservation Code
,
shall be tested in accordance with ASTM E 84 or UL 723, using the specimen 
preparation and mounting p
rocedures of ASTM E 2231; and shall have a maximum flame spread index of 25 and a 
smoke
-
developed index not exceeding 450. Insulation installed in an air plenum shall comply with Section 602.2.1.
1204.2 Required thickness. 
Hydronic piping shall be insulate
d to the thickness required by the 
New York City
Energy 
Conservation Code.
SECTION 
MC 
1205
VALVES
1205.1 Where required. 
Shutoff valves shall be installed in hydronic piping systems in the locations indicated in 
Sections 1205.1.1 through 1205.1.6.
1205.1.1
Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
HYDRONIC PIPING
Exception: 
Shutoff valves shall not be required where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat 
exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1205.1.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of central utility 
systems, and district
heating and cooling 
systems.
1205.1.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1205.1.4 Pressure
-
reducing valves. 
Shutoff valves shall be installed on both sides of a pressure
-
reduc
ing valve.
1205.1.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a hydronic system such as pumps, air separators, 
metering devices and si
milar equipment.
1205.1.6 Expansion tanks.
Lockable shutoff
valves shall be installed at connections to 
all
expansion tanks.
Valves shall be locked in the open position.
1205.2 Reduced pressure. 
A pressure relief valve shall be installed on the 
low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system design. 
The valve shall be installed in accordance with Section 1006.
SECTION 
MC 
1206
PIPING INSTALLATION
1
206.1 General. 
Piping, valves, fittings and connections shall be installed in accordance with the conditions of ap-
proval.
1206.2 System drain down. 
Hydronic piping systems shall be designed and installed to permit the system to be 
drained. Where the system
drains to the plumbing drainage system, the installation shall conform to the requirements 
of the 
New York City
Plumbing Code.
Exception: 
The buried portions of systems embedded underground.
1206.3 Protection of potable water. 
The potable water system sha
ll be protected from backflow in accordance with 
the 
New York City
Plumbing Code.
1206.4 Pipe penetrations. 
Openings for pipe penetrations in walls, floors or ceilings shall be larger than the penetrat-
ing pipe. Openings through concrete or masonry building
elements shall be sleeved. The annular space surrounding 
pipe penetrations shall be protected in accordance with the 
New York City
Building Code.
1206.5 Clearance to combustibles. 
A pipe in a hydronic piping system in which the exterior temperature exceed
s 
250°F (
121.1
°C) shall have a minimum clearance of 1 inch (25.4 mm) to combustible materials.
1206.6 Contact with building material. 
A hydronic piping system shall not be in direct contact with building mate-
rials that cause the piping material to degrade 
or corrode, or that interfere with the operation of the system.
1206.7 Water hammer. 
The flow velocity of the hydronic piping system shall be controlled to reduce the possibility 
of water hammer. Where a quick
-
closing valve creates water hammer, an 
enginee
red
water
-
hammer arrestor shall be 
installed. The arrestor shall be located within a range as specified by the manufacturer of the quick
-
closing valve.
1206.8 Steam piping pitch. 
Steam piping shall be installed to drain to the boiler or the steam trap. Ste
am systems 
shall not have drip pockets that reduce the capacity of the steam piping.
1206.9 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains and stresses in the pipe. 
Provisions shall be made to protect piping from damag
e resulting from expansion, contraction and structural settle-
ment. Piping shall be installed so as to avoid structural stresses or strains within building components.
1206.9.1 Flood hazard. 
Piping located in flood hazard areas 
shall comply with Appendix G
of 
the 
New York City 
Building Code
.
‡‡‡ Chapter 12 was amended by 
Local Law 
77 
of 2023
. This law has an effective
date of June 10, 2023.
CHAPTER 12
HYDRONIC PIPING 
SECTION MC 1201
GENERAL
1201.1 Scope. 
The provisions of this chapter shall govern the construction, installation, alteration and repair of hy-
dronic piping systems. This chapter shall apply to hydronic piping systems that are part of heating, ventilation and air
-
conditioning systems. Such piping systems shall include steam, hot water, chilled water, condenser water, cooling 
coil condensate drain, 
steam condensate and ground
-
source heat pump loop systems. Potable cold and hot water dis-
tribution systems shall be installed in accordance with the 
New York City
Plumbing Code
. 
1201.2 Sizing. 
Piping and piping system components for hydronic systems shall be sized for the 
design requirements
of the system.
1201.3 Standards. 
As an alternative to the provisions of Sections 1202 and 1203, piping shall be designed, installed, 
inspected and tested in accordance with ASME B31.
1 and ASME B31.9, as applicable
. 
SECTION 
MC 
1202
MATERIAL
1202.1 Piping. 
Piping material, other than those contained within this section and conforming with the ASTM stand-
ards listed within this chapter, shall be of an approved type.
Exception: 
Embedded piping regulated by Section 1209, and ground
-
source heat pump loop systems regulated by 
Section 1210.
1202.2 Used existing materials. 
Reused pipe, fittings, valves or other materials shall be clean and free of foreign 
materials.
1202.3 Material rating. 
Materials shall be rated for the operating temperature and pressure of the hydronic system. 
Materials shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards. 
Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior 
of the pipe shall be protected from corrosion and d
egradation.
TABLE 1202.4
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene 
(ABS) plastic pipe
ASTM D 1527; ASTM F 2806
Chlorinated polyvinyl chloride 
(CPVC) plastic pipe
ASTM D 2846; ASTM F 441; 
ASTM F 442
Copper, 
brass, or copper
-
alloy 
pipe
ASTM B 42; ASTM B 43; 
ASTM B 302
Copper, brass, or copper
-
alloy 
tube (Type K, L or M)
ASTM B 75; ASTM B 88; 
ASTM B 135; ASTM B 251
HYDRONIC PIPING
Cross
-
linked 
polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe
ASTM F 1281; CSA
B137.10
Cross
-
linked polyethylene 
(PEX) tubing
ASTM F 876; ASTM F 877
Ductile iron pipe
AWWA C115/A21.15; AWWA 
C151/A21.51 
Polyethylene/aluminum/
polyet
hylene 
(PE
-
AL
-
PE) pressure 
pipe
ASTM F 1282; CSA B137.9
Polypropylene (PP) 
plastic pipe
ASTM F 2389
Polyvinyl chloride (PVC) 
plastic pipe
ASTM D 1785; ASTM D 2241
Raised temperature 
polyethylene (PE
-
RT)
ASTM F 2623; ASTM F 2769
Steel pipe
ASTM A 53/A 53M; ASTM A 
106
Steel tubing
ASTM A 254
1202.5 Pipe fittings. 
Hydronic pipe fittings shall conform to the respective pipe standards or to the standards listed in 
Table 1202.5.
TABLE 1202.5
HYDRONIC PIPE FITTINGS
MATERIAL
STANDARD (see Chapter 15)
Copper, brass, and copper 
alloys
ASME B16.15; ASME B16.18; ASME 
B16.22; 
ASME B16.24; 
ASME 
B16.26; 
ASME B16.51; ASTM F 
1974 
Ductile iron and gray iron
ANSI/AWWA C110/A21.10; 
AWWA C153/A21.53; ASTM A 
126; ASTM A 395; ASTM A 536; 
ASTM F 1476; ASTM F 1548
Malleable iron
ASME B16.3
PE
-
RT fittings
ASTM F 1807; ASTM F 2098; 
ASTM F 2159; ASTM F 2735; 
ASTM F 2769
PEX fittings
ASTM F 877; ASTM F 1807; ASTM 
F 2159
Plastic
ASTM D 2466; ASTM D 2467; 
ASTM F 438; ASTM F 439; ASTM 
F
877; ASTM F 2389; ASTM F 2735
HYDRONIC PIPING
Steel
ASME B16.5; ASME 
B16.9; ASME 
B16.11; ASME B16.28; ASTM A 
53/A 53M; ASTM A 106; ASTM A 
234; ASTM A 420; ASTM A 536; 
ASTM A 395; ASTM F 1476; ASTM 
F 1548
1202.6 Valves. 
Valves shall be constructed of materials that are compatible with the type of piping material and fluids 
in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration compensators. 
Flexible connectors, expansion and vibration 
control devices and fit
tings
, when used, shall protect the components of the hydronic system from damage caused by 
expansion, contraction, transverse movement, angular deflection and vibration,
shall be 
rated for the temperatures 
and pressures of the systems in which the devices
are installed, and shall be compatible with the fluid and all materials 
provided
.
SECTION 
MC 
1203
JOINTS AND CONNECTIONS
1203.1 Approval. 
Joints and connections
, other than those contained in Section 1203 and conforming to the ASTM 
standards listed in Sec
tion 1203,
shall be of an approved type. Joints and connections shall be tight for the pressure 
of the hydronic system.
1203.1.1 Joints between different piping materials. 
Joints between different piping materials shall be 
rated for 
the temperatures and pr
essures of the systems in which the devices are installed and shall be compatible with the 
fluid and all materials provided. 
1203.
1.2 Joints between dissimilar metallic piping materials.
Joints between dissimilar metallic piping mate-
rials shall be provide
d to protect against galvanic corrosion. Such joints shall be 
made with 
dielectric fittings 
conforming to ANSI B16.39 or ASTM F 492, as applicable, shall be rated for the temperatures and pressures of 
the systems in which the devices are installed and shal
l be compatible with the fluid and all materials provided
.
Exception:
Dielectric fittings shall not be required for joints between dissimilar metal piping used within heat 
transfer appliances or equipment when such joints are provided by the appliance or e
quipment manufacturer, 
and such appliance or equipment is connected with isolation valves that are accessible.
1203.2 Preparation of pipe ends. 
Pipe shall be cut square, reamed and chamfered, and shall be free of burrs and 
obstructions. Pipe ends shall hav
e full
-
bore openings and shall not be undercut.
1203.3 Joint preparation and installation. 
Where required by Sections 1203.4 through 1203.14, the preparation and 
installation of brazed, mechanical, soldered, 
solvent
-
cemented
, threaded and welded joints shall comply with Sections 
1203.3.1 through 1203.3.8.
1203.3.1 Brazed joints.
All joints 
shall
be brazed with a 
brazing procedure developed and qualified in accordance 
with the ASME
Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications) or in accord-
ance with 
AWS 
B2.2 Standard for Brazing Procedure and Performance Qualifica
tion
.
1203.3.2 Mechanical joints. 
Mechanical joints shall be installed in accordance with the manufacturer’s instruc-
tions.
1203.3.3 Soldered joints. 
Joint surfaces shall be cleaned. A flux conforming to ASTM B 813 shall be applied. The 
joint shall be solde
red with a solder conforming to ASTM B 32.
1203.3.4 Solvent
-
cemented joints. 
Joint surfaces shall be clean and free of moisture. 
A
primer
, compatible with 
both the piping material and the cement
shall be applied to pipe
-
joint surfaces
, in accordance with t
he manufac-
turer’s requirements
. Joints shall be made while the cement is wet. Solvent cement conforming to the following 
standards shall be applied to all joint surfaces:
1.
ASTM D 2235 for ABS joints.
2.
ASTM F 493 for CPVC joints.
HYDRONIC PIPING
3.
ASTM D 2564 for PVC 
joints.
1203.3.5 Threaded joints. 
Threads shall conform to ASME B1.20.1. Schedule 80 or heavier plastic pipe shall be 
threaded with dies specifically designed for plastic pipe. Thread lubricant, pipe
-
joint compound or tape shall be 
applied on the male threads only and shall be 
compatible
f
or application on the piping material
and fluid
.
1203.3.6 Welded joints.
All joints shall be welded with a welding procedure developed and qualified in accord-
ance with the 
ASME Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications
) or in 
accordance with AWS B2.1 Specifications for Welding Procedure and Performance Qualification.
1203.3.7 Grooved and shouldered mechanical joints. 
Grooved and shouldered mechanical joints shall conform 
to the requirements of ASTM F 1476 and shall be i
nstalled in accordance with the manufacturer’s
instructions.
1203.3.8 Mechanically formed tee fittings. 
Mechanically extracted outlets shall have a height not less than three 
times the thickness of the branch tube wall.
1203.3.8.1 Full flow assurance. 
Bran
ch tubes shall not restrict the flow in the run tube. A dimple/depth stop 
shall be formed in the branch tube to ensure that penetration into the outlet is of the correct depth. For inspection 
purposes, a second dimple shall be placed
1
/
4
inch (6.4 mm) above the first dimple. Dimples shall be aligned 
with the tube run.
1203.3.8.2 Brazed joints. 
Mechanically formed tee fittings shall be brazed in accordance with Section 1203.3.1.
1203.4 ABS plastic pipe. 
Joints between ABS plastic pipe or f
ittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.5 Brass pipe. 
Joints between brass pipe or fittings shall be brazed, mechanical, threaded or welded joints con-
forming to Section 1203.3.
1203.6 Brass tubing. 
Joints bet
ween brass tubing or fittings shall be brazed, mechanical or soldered joints conforming 
to Section 1203.3.
1203.7 Copper or copper
-
alloy pipe. 
Joints between copper or copper
-
alloy pipe or fittings shall be brazed, mechan-
ical, soldered, threaded or welded 
joints conforming to Section 1203.3.
1203.8 Copper or copper
-
alloy tubing. 
Joints between copper or copper
-
alloy tubing or fittings shall be brazed, 
mechanical or soldered joints conforming to Section 1203.3, flared joints conforming to Section 1203.8.1
or
push
-
fit 
joints conforming to Section 1203.8.2.
1203.8.1 Flared joints. 
Flared joints shall be made by a tool designed for that operation.
1203.8.2 Push
-
fit joints. 
Push
-
fit joints shall be installed in accordance with the manufacturer’s instructions.
120
3.9 CPVC plastic pipe.   
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.10 Reserved.
1203.11 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints between cross
-
linked polyethyle
ne plastic tubing 
and fittings shall conform to Sections 1203.11.1 and 1203.11.2. Mechanical joints shall conform to Section 1203.3.
1203.11.1 Compression
-
type fittings. 
Where
compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings 
shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.11.2 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not less 
than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same 
water line.
1203.12 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.13 Steel pipe. 
Joints between steel pipe or fittings shall be mechanical
, threaded or welded 
joints 
conforming to 
Section 1203.3.
1203.14 Steel tubing. 
Joints between steel tubing or fittings shall be mechanical or welded joints conforming to Sec-
tion 1203.3.
HYDRONIC PIPING
1203.15 Polypropylene (PP) plastic. 
Joints between PP plastic pipe and fittings shall comp
ly with Sections 1203.15.1 
and 1203.15.2.
1203.15.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylene fittings, electro
-
fusion polypropylene fittings or by butt
fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1203.15.2 Mechanical and compression sleeve joints. 
Mechanical and compression sleeve joints shal
l be installed 
in accordance with the manufacturer’s instructions.
1203.16 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyethylene 
tubing and fittings shall conform to Sections 1203.16.1 and 1203.16.2. Mechani
cal joints shall conform to Section 
1203.3.
1203.16.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.16.2 PE
-
RT
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 mm) 
of a transition from such metal pipe to PE
-
RT pipe.
1203.17 Polyethylene/aluminum/polyethylene (PE
-
AL
-
PE) pressure pipe. 
Joints between polyethylene/alumi-
num/po
lyethylene pressure pipe and fittings shall conform to Sections 1203.17.1 and 1203.17.2. Mechanical joints 
shall comply with Section 1203.3.
1203.17.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
f
ittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.17.2 PE
-
AL
-
PE
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 
mm) of a transition from such metal pipe to PE
-
AL
-
PE pipe.
1203.18 Cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe. 
Joints 
between cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene pressure pipe and fittings shall conform to 
Sections 1203.18.1 and 1203.18.2. Mecha
nical joints shall comply with Section 1203.3.
1203.18.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.18.2 PEX
-
AL
-
PEX
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches 
(457.2 mm) of a transition from such metal pipe to PEX
-
AL
-
PEX pipe.
SECTION 
MC 
1204
PIPE INSULATION
1204.1 Insulation characteristics. 
Pipe insulation installed in buildings shall conform to the requirements of the 
New 
York City
Energy Conservation Code
,
shall be tested in accordance with ASTM E 84 or UL 723, using the specimen 
preparation and mounting p
rocedures of ASTM E 2231; and shall have a maximum flame spread index of 25 and a 
smoke
-
developed index not exceeding 450. Insulation installed in an air plenum shall comply with Section 602.2.1.
1204.2 Required thickness. 
Hydronic piping shall be insulate
d to the thickness required by the 
New York City
Energy 
Conservation Code.
SECTION 
MC 
1205
VALVES
1205.1 Where required. 
Shutoff valves shall be installed in hydronic piping systems in the locations indicated in 
Sections 1205.1.1 through 1205.1.6.
1205.1.1
Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
HYDRONIC PIPING
Exception: 
Shutoff valves shall not be required where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat 
exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1205.1.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of central utility 
systems, and district
heating and cooling 
systems.
1205.1.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1205.1.4 Pressure
-
reducing valves. 
Shutoff valves shall be installed on both sides of a pressure
-
reduc
ing valve.
1205.1.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a hydronic system such as pumps, air separators, 
metering devices and si
milar equipment.
1205.1.6 Expansion tanks.
Lockable shutoff
valves shall be installed at connections to 
all
expansion tanks.
Valves shall be locked in the open position.
1205.2 Reduced pressure. 
A pressure relief valve shall be installed on the 
low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system design. 
The valve shall be installed in accordance with Section 1006.
SECTION 
MC 
1206
PIPING INSTALLATION
1
206.1 General. 
Piping, valves, fittings and connections shall be installed in accordance with the conditions of ap-
proval.
1206.2 System drain down. 
Hydronic piping systems shall be designed and installed to permit the system to be 
drained. Where the system
drains to the plumbing drainage system, the installation shall conform to the requirements 
of the 
New York City
Plumbing Code.
Exception: 
The buried portions of systems embedded underground.
1206.3 Protection of potable water. 
The potable water system sha
ll be protected from backflow in accordance with 
the 
New York City
Plumbing Code.
1206.4 Pipe penetrations. 
Openings for pipe penetrations in walls, floors or ceilings shall be larger than the penetrat-
ing pipe. Openings through concrete or masonry building
elements shall be sleeved. The annular space surrounding 
pipe penetrations shall be protected in accordance with the 
New York City
Building Code.
1206.5 Clearance to combustibles. 
A pipe in a hydronic piping system in which the exterior temperature exceed
s 
250°F (
121.1
°C) shall have a minimum clearance of 1 inch (25.4 mm) to combustible materials.
1206.6 Contact with building material. 
A hydronic piping system shall not be in direct contact with building mate-
rials that cause the piping material to degrade 
or corrode, or that interfere with the operation of the system.
1206.7 Water hammer. 
The flow velocity of the hydronic piping system shall be controlled to reduce the possibility 
of water hammer. Where a quick
-
closing valve creates water hammer, an 
enginee
red
water
-
hammer arrestor shall be 
installed. The arrestor shall be located within a range as specified by the manufacturer of the quick
-
closing valve.
1206.8 Steam piping pitch. 
Steam piping shall be installed to drain to the boiler or the steam trap. Ste
am systems 
shall not have drip pockets that reduce the capacity of the steam piping.
1206.9 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains and stresses in the pipe. 
Provisions shall be made to protect piping from damag
e resulting from expansion, contraction and structural settle-
ment. Piping shall be installed so as to avoid structural stresses or strains within building components.
1206.9.1 Flood hazard. 
Piping located in flood hazard areas 
shall comply with Appendix G
of 
the 
New York City 
Building Code
.
HYDRONIC PIPING
1206.10 Pipe support. 
Pipe shall be supported in accordance with Section 305.
Seismic supports shall be provided 
where required by the 
New York City Building Code.
1206.11 Condensation. 
Provisions shall be made to prevent the formation of condensation on the exterior of piping.
SECTION 
MC 
1207
TRANSFER FLUID
1207.1 Flash point. 
The
flash point of transfer fluid in a hydronic piping system shall be not less than 50°F (10°C) 
above the maximum system operating temperature.
1207.2 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
SECTION 
MC 
1208
TESTS
1208.1 General. 
Hydronic piping systems 
other than ground
-
source heat pump loop systems 
shall be tested hydro-
statically at one and one
half times the system design 
operating 
pressure, but not less than 100 psi (689 kPa). The 
duration of each 
test shall be not less than
2 hours. Ground
-
source heat pump loop systems shall be tested in accord-
ance with Section 1210.10.
SECTION 
MC 
1209
EMBEDDED PIPING
1209.1 Materials. 
Embedded piping
shall be plastic pipe or tubing
, in accordance with Section 1202
,
rated at 100 psi 
(689.5 kPa) at 180°F (82.2°C).
1209.2 Pressurizing during installation. 
Piping to be embedded in concrete shall be pressure tested prior to pouring 
concrete. During pouring, the pipe shall be maintained at the proposed operating pressure
.
1209.3 Embedded joints. 
Joints of pipe or tubing that are embedded in a portion of the building, such as concrete or 
plaster, shall be thermally
-
fused.
1209.4 Not embedded related piping. 
Joints of other piping in cavities or running exposed shall be joi
ned in accord-
ance with manufacturer’s instructions and related sections of this code.
1209.5 Thermal barrier required. 
Radiant floor heating systems shall be provided with a thermal barrier in accord-
ance with Sections 1209.5.1 through 1209.5.4.
Exception: 
Insulation shall not be required in engineered systems where it can be demonstrated that the insulation 
will decrease the efficiency or have a negative effect on the installation.
1209.5.1 Slab
-
on
-
grade installation. 
Radiant piping utilized in slab
-
on
-
grad
e applications shall be provided with 
insulating materials installed beneath the piping having a minimum R
-
value of 5.
1209.5.2 Suspended floor installation. 
In suspended floor applications, insulation shall be installed in the joist 
bay cavity serving the
heating space above and shall consist of materials having a minimum R
-
value of 11.
1209.5.3 Thermal break required. 
A thermal break shall be provided consisting of asphalt expansion joint mate-
rials or similar insulating materials at a point where a heated
slab meets a foundation wall or other conductive slab.
1209.5.4 Thermal barrier material marking. 
Insulating materials utilized in thermal barriers shall be installed 
such that the manufacturer’s R
-
value mark is readily observable upon inspection.
SECTION
MC 
1210
PLASTIC PIPE GROUND
-
SOURCE HEAT PUMP LOOP SYSTEMS
‡‡‡ Chapter 12 was amended by 
Local Law 
77 
of 2023
. This law has an effective
date of June 10, 2023.
CHAPTER 12
HYDRONIC PIPING 
SECTION MC 1201
GENERAL
1201.1 Scope. 
The provisions of this chapter shall govern the construction, installation, alteration and repair of hy-
dronic piping systems. This chapter shall apply to hydronic piping systems that are part of heating, ventilation and air
-
conditioning systems. Such piping systems shall include steam, hot water, chilled water, condenser water, cooling 
coil condensate drain, 
steam condensate and ground
-
source heat pump loop systems. Potable cold and hot water dis-
tribution systems shall be installed in accordance with the 
New York City
Plumbing Code
. 
1201.2 Sizing. 
Piping and piping system components for hydronic systems shall be sized for the 
design requirements
of the system.
1201.3 Standards. 
As an alternative to the provisions of Sections 1202 and 1203, piping shall be designed, installed, 
inspected and tested in accordance with ASME B31.
1 and ASME B31.9, as applicable
. 
SECTION 
MC 
1202
MATERIAL
1202.1 Piping. 
Piping material, other than those contained within this section and conforming with the ASTM stand-
ards listed within this chapter, shall be of an approved type.
Exception: 
Embedded piping regulated by Section 1209, and ground
-
source heat pump loop systems regulated by 
Section 1210.
1202.2 Used existing materials. 
Reused pipe, fittings, valves or other materials shall be clean and free of foreign 
materials.
1202.3 Material rating. 
Materials shall be rated for the operating temperature and pressure of the hydronic system. 
Materials shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards. 
Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior 
of the pipe shall be protected from corrosion and d
egradation.
TABLE 1202.4
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene 
(ABS) plastic pipe
ASTM D 1527; ASTM F 2806
Chlorinated polyvinyl chloride 
(CPVC) plastic pipe
ASTM D 2846; ASTM F 441; 
ASTM F 442
Copper, 
brass, or copper
-
alloy 
pipe
ASTM B 42; ASTM B 43; 
ASTM B 302
Copper, brass, or copper
-
alloy 
tube (Type K, L or M)
ASTM B 75; ASTM B 88; 
ASTM B 135; ASTM B 251
HYDRONIC PIPING
Cross
-
linked 
polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe
ASTM F 1281; CSA
B137.10
Cross
-
linked polyethylene 
(PEX) tubing
ASTM F 876; ASTM F 877
Ductile iron pipe
AWWA C115/A21.15; AWWA 
C151/A21.51 
Polyethylene/aluminum/
polyet
hylene 
(PE
-
AL
-
PE) pressure 
pipe
ASTM F 1282; CSA B137.9
Polypropylene (PP) 
plastic pipe
ASTM F 2389
Polyvinyl chloride (PVC) 
plastic pipe
ASTM D 1785; ASTM D 2241
Raised temperature 
polyethylene (PE
-
RT)
ASTM F 2623; ASTM F 2769
Steel pipe
ASTM A 53/A 53M; ASTM A 
106
Steel tubing
ASTM A 254
1202.5 Pipe fittings. 
Hydronic pipe fittings shall conform to the respective pipe standards or to the standards listed in 
Table 1202.5.
TABLE 1202.5
HYDRONIC PIPE FITTINGS
MATERIAL
STANDARD (see Chapter 15)
Copper, brass, and copper 
alloys
ASME B16.15; ASME B16.18; ASME 
B16.22; 
ASME B16.24; 
ASME 
B16.26; 
ASME B16.51; ASTM F 
1974 
Ductile iron and gray iron
ANSI/AWWA C110/A21.10; 
AWWA C153/A21.53; ASTM A 
126; ASTM A 395; ASTM A 536; 
ASTM F 1476; ASTM F 1548
Malleable iron
ASME B16.3
PE
-
RT fittings
ASTM F 1807; ASTM F 2098; 
ASTM F 2159; ASTM F 2735; 
ASTM F 2769
PEX fittings
ASTM F 877; ASTM F 1807; ASTM 
F 2159
Plastic
ASTM D 2466; ASTM D 2467; 
ASTM F 438; ASTM F 439; ASTM 
F
877; ASTM F 2389; ASTM F 2735
HYDRONIC PIPING
Steel
ASME B16.5; ASME 
B16.9; ASME 
B16.11; ASME B16.28; ASTM A 
53/A 53M; ASTM A 106; ASTM A 
234; ASTM A 420; ASTM A 536; 
ASTM A 395; ASTM F 1476; ASTM 
F 1548
1202.6 Valves. 
Valves shall be constructed of materials that are compatible with the type of piping material and fluids 
in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration compensators. 
Flexible connectors, expansion and vibration 
control devices and fit
tings
, when used, shall protect the components of the hydronic system from damage caused by 
expansion, contraction, transverse movement, angular deflection and vibration,
shall be 
rated for the temperatures 
and pressures of the systems in which the devices
are installed, and shall be compatible with the fluid and all materials 
provided
.
SECTION 
MC 
1203
JOINTS AND CONNECTIONS
1203.1 Approval. 
Joints and connections
, other than those contained in Section 1203 and conforming to the ASTM 
standards listed in Sec
tion 1203,
shall be of an approved type. Joints and connections shall be tight for the pressure 
of the hydronic system.
1203.1.1 Joints between different piping materials. 
Joints between different piping materials shall be 
rated for 
the temperatures and pr
essures of the systems in which the devices are installed and shall be compatible with the 
fluid and all materials provided. 
1203.
1.2 Joints between dissimilar metallic piping materials.
Joints between dissimilar metallic piping mate-
rials shall be provide
d to protect against galvanic corrosion. Such joints shall be 
made with 
dielectric fittings 
conforming to ANSI B16.39 or ASTM F 492, as applicable, shall be rated for the temperatures and pressures of 
the systems in which the devices are installed and shal
l be compatible with the fluid and all materials provided
.
Exception:
Dielectric fittings shall not be required for joints between dissimilar metal piping used within heat 
transfer appliances or equipment when such joints are provided by the appliance or e
quipment manufacturer, 
and such appliance or equipment is connected with isolation valves that are accessible.
1203.2 Preparation of pipe ends. 
Pipe shall be cut square, reamed and chamfered, and shall be free of burrs and 
obstructions. Pipe ends shall hav
e full
-
bore openings and shall not be undercut.
1203.3 Joint preparation and installation. 
Where required by Sections 1203.4 through 1203.14, the preparation and 
installation of brazed, mechanical, soldered, 
solvent
-
cemented
, threaded and welded joints shall comply with Sections 
1203.3.1 through 1203.3.8.
1203.3.1 Brazed joints.
All joints 
shall
be brazed with a 
brazing procedure developed and qualified in accordance 
with the ASME
Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications) or in accord-
ance with 
AWS 
B2.2 Standard for Brazing Procedure and Performance Qualifica
tion
.
1203.3.2 Mechanical joints. 
Mechanical joints shall be installed in accordance with the manufacturer’s instruc-
tions.
1203.3.3 Soldered joints. 
Joint surfaces shall be cleaned. A flux conforming to ASTM B 813 shall be applied. The 
joint shall be solde
red with a solder conforming to ASTM B 32.
1203.3.4 Solvent
-
cemented joints. 
Joint surfaces shall be clean and free of moisture. 
A
primer
, compatible with 
both the piping material and the cement
shall be applied to pipe
-
joint surfaces
, in accordance with t
he manufac-
turer’s requirements
. Joints shall be made while the cement is wet. Solvent cement conforming to the following 
standards shall be applied to all joint surfaces:
1.
ASTM D 2235 for ABS joints.
2.
ASTM F 493 for CPVC joints.
HYDRONIC PIPING
3.
ASTM D 2564 for PVC 
joints.
1203.3.5 Threaded joints. 
Threads shall conform to ASME B1.20.1. Schedule 80 or heavier plastic pipe shall be 
threaded with dies specifically designed for plastic pipe. Thread lubricant, pipe
-
joint compound or tape shall be 
applied on the male threads only and shall be 
compatible
f
or application on the piping material
and fluid
.
1203.3.6 Welded joints.
All joints shall be welded with a welding procedure developed and qualified in accord-
ance with the 
ASME Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications
) or in 
accordance with AWS B2.1 Specifications for Welding Procedure and Performance Qualification.
1203.3.7 Grooved and shouldered mechanical joints. 
Grooved and shouldered mechanical joints shall conform 
to the requirements of ASTM F 1476 and shall be i
nstalled in accordance with the manufacturer’s
instructions.
1203.3.8 Mechanically formed tee fittings. 
Mechanically extracted outlets shall have a height not less than three 
times the thickness of the branch tube wall.
1203.3.8.1 Full flow assurance. 
Bran
ch tubes shall not restrict the flow in the run tube. A dimple/depth stop 
shall be formed in the branch tube to ensure that penetration into the outlet is of the correct depth. For inspection 
purposes, a second dimple shall be placed
1
/
4
inch (6.4 mm) above the first dimple. Dimples shall be aligned 
with the tube run.
1203.3.8.2 Brazed joints. 
Mechanically formed tee fittings shall be brazed in accordance with Section 1203.3.1.
1203.4 ABS plastic pipe. 
Joints between ABS plastic pipe or f
ittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.5 Brass pipe. 
Joints between brass pipe or fittings shall be brazed, mechanical, threaded or welded joints con-
forming to Section 1203.3.
1203.6 Brass tubing. 
Joints bet
ween brass tubing or fittings shall be brazed, mechanical or soldered joints conforming 
to Section 1203.3.
1203.7 Copper or copper
-
alloy pipe. 
Joints between copper or copper
-
alloy pipe or fittings shall be brazed, mechan-
ical, soldered, threaded or welded 
joints conforming to Section 1203.3.
1203.8 Copper or copper
-
alloy tubing. 
Joints between copper or copper
-
alloy tubing or fittings shall be brazed, 
mechanical or soldered joints conforming to Section 1203.3, flared joints conforming to Section 1203.8.1
or
push
-
fit 
joints conforming to Section 1203.8.2.
1203.8.1 Flared joints. 
Flared joints shall be made by a tool designed for that operation.
1203.8.2 Push
-
fit joints. 
Push
-
fit joints shall be installed in accordance with the manufacturer’s instructions.
120
3.9 CPVC plastic pipe.   
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.10 Reserved.
1203.11 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints between cross
-
linked polyethyle
ne plastic tubing 
and fittings shall conform to Sections 1203.11.1 and 1203.11.2. Mechanical joints shall conform to Section 1203.3.
1203.11.1 Compression
-
type fittings. 
Where
compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings 
shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.11.2 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not less 
than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same 
water line.
1203.12 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.13 Steel pipe. 
Joints between steel pipe or fittings shall be mechanical
, threaded or welded 
joints 
conforming to 
Section 1203.3.
1203.14 Steel tubing. 
Joints between steel tubing or fittings shall be mechanical or welded joints conforming to Sec-
tion 1203.3.
HYDRONIC PIPING
1203.15 Polypropylene (PP) plastic. 
Joints between PP plastic pipe and fittings shall comp
ly with Sections 1203.15.1 
and 1203.15.2.
1203.15.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylene fittings, electro
-
fusion polypropylene fittings or by butt
fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1203.15.2 Mechanical and compression sleeve joints. 
Mechanical and compression sleeve joints shal
l be installed 
in accordance with the manufacturer’s instructions.
1203.16 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyethylene 
tubing and fittings shall conform to Sections 1203.16.1 and 1203.16.2. Mechani
cal joints shall conform to Section 
1203.3.
1203.16.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.16.2 PE
-
RT
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 mm) 
of a transition from such metal pipe to PE
-
RT pipe.
1203.17 Polyethylene/aluminum/polyethylene (PE
-
AL
-
PE) pressure pipe. 
Joints between polyethylene/alumi-
num/po
lyethylene pressure pipe and fittings shall conform to Sections 1203.17.1 and 1203.17.2. Mechanical joints 
shall comply with Section 1203.3.
1203.17.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
f
ittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.17.2 PE
-
AL
-
PE
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 
mm) of a transition from such metal pipe to PE
-
AL
-
PE pipe.
1203.18 Cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe. 
Joints 
between cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene pressure pipe and fittings shall conform to 
Sections 1203.18.1 and 1203.18.2. Mecha
nical joints shall comply with Section 1203.3.
1203.18.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.18.2 PEX
-
AL
-
PEX
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches 
(457.2 mm) of a transition from such metal pipe to PEX
-
AL
-
PEX pipe.
SECTION 
MC 
1204
PIPE INSULATION
1204.1 Insulation characteristics. 
Pipe insulation installed in buildings shall conform to the requirements of the 
New 
York City
Energy Conservation Code
,
shall be tested in accordance with ASTM E 84 or UL 723, using the specimen 
preparation and mounting p
rocedures of ASTM E 2231; and shall have a maximum flame spread index of 25 and a 
smoke
-
developed index not exceeding 450. Insulation installed in an air plenum shall comply with Section 602.2.1.
1204.2 Required thickness. 
Hydronic piping shall be insulate
d to the thickness required by the 
New York City
Energy 
Conservation Code.
SECTION 
MC 
1205
VALVES
1205.1 Where required. 
Shutoff valves shall be installed in hydronic piping systems in the locations indicated in 
Sections 1205.1.1 through 1205.1.6.
1205.1.1
Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
HYDRONIC PIPING
Exception: 
Shutoff valves shall not be required where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat 
exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1205.1.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of central utility 
systems, and district
heating and cooling 
systems.
1205.1.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1205.1.4 Pressure
-
reducing valves. 
Shutoff valves shall be installed on both sides of a pressure
-
reduc
ing valve.
1205.1.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a hydronic system such as pumps, air separators, 
metering devices and si
milar equipment.
1205.1.6 Expansion tanks.
Lockable shutoff
valves shall be installed at connections to 
all
expansion tanks.
Valves shall be locked in the open position.
1205.2 Reduced pressure. 
A pressure relief valve shall be installed on the 
low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system design. 
The valve shall be installed in accordance with Section 1006.
SECTION 
MC 
1206
PIPING INSTALLATION
1
206.1 General. 
Piping, valves, fittings and connections shall be installed in accordance with the conditions of ap-
proval.
1206.2 System drain down. 
Hydronic piping systems shall be designed and installed to permit the system to be 
drained. Where the system
drains to the plumbing drainage system, the installation shall conform to the requirements 
of the 
New York City
Plumbing Code.
Exception: 
The buried portions of systems embedded underground.
1206.3 Protection of potable water. 
The potable water system sha
ll be protected from backflow in accordance with 
the 
New York City
Plumbing Code.
1206.4 Pipe penetrations. 
Openings for pipe penetrations in walls, floors or ceilings shall be larger than the penetrat-
ing pipe. Openings through concrete or masonry building
elements shall be sleeved. The annular space surrounding 
pipe penetrations shall be protected in accordance with the 
New York City
Building Code.
1206.5 Clearance to combustibles. 
A pipe in a hydronic piping system in which the exterior temperature exceed
s 
250°F (
121.1
°C) shall have a minimum clearance of 1 inch (25.4 mm) to combustible materials.
1206.6 Contact with building material. 
A hydronic piping system shall not be in direct contact with building mate-
rials that cause the piping material to degrade 
or corrode, or that interfere with the operation of the system.
1206.7 Water hammer. 
The flow velocity of the hydronic piping system shall be controlled to reduce the possibility 
of water hammer. Where a quick
-
closing valve creates water hammer, an 
enginee
red
water
-
hammer arrestor shall be 
installed. The arrestor shall be located within a range as specified by the manufacturer of the quick
-
closing valve.
1206.8 Steam piping pitch. 
Steam piping shall be installed to drain to the boiler or the steam trap. Ste
am systems 
shall not have drip pockets that reduce the capacity of the steam piping.
1206.9 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains and stresses in the pipe. 
Provisions shall be made to protect piping from damag
e resulting from expansion, contraction and structural settle-
ment. Piping shall be installed so as to avoid structural stresses or strains within building components.
1206.9.1 Flood hazard. 
Piping located in flood hazard areas 
shall comply with Appendix G
of 
the 
New York City 
Building Code
.
HYDRONIC PIPING
1206.10 Pipe support. 
Pipe shall be supported in accordance with Section 305.
Seismic supports shall be provided 
where required by the 
New York City Building Code.
1206.11 Condensation. 
Provisions shall be made to prevent the formation of condensation on the exterior of piping.
SECTION 
MC 
1207
TRANSFER FLUID
1207.1 Flash point. 
The
flash point of transfer fluid in a hydronic piping system shall be not less than 50°F (10°C) 
above the maximum system operating temperature.
1207.2 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
SECTION 
MC 
1208
TESTS
1208.1 General. 
Hydronic piping systems 
other than ground
-
source heat pump loop systems 
shall be tested hydro-
statically at one and one
half times the system design 
operating 
pressure, but not less than 100 psi (689 kPa). The 
duration of each 
test shall be not less than
2 hours. Ground
-
source heat pump loop systems shall be tested in accord-
ance with Section 1210.10.
SECTION 
MC 
1209
EMBEDDED PIPING
1209.1 Materials. 
Embedded piping
shall be plastic pipe or tubing
, in accordance with Section 1202
,
rated at 100 psi 
(689.5 kPa) at 180°F (82.2°C).
1209.2 Pressurizing during installation. 
Piping to be embedded in concrete shall be pressure tested prior to pouring 
concrete. During pouring, the pipe shall be maintained at the proposed operating pressure
.
1209.3 Embedded joints. 
Joints of pipe or tubing that are embedded in a portion of the building, such as concrete or 
plaster, shall be thermally
-
fused.
1209.4 Not embedded related piping. 
Joints of other piping in cavities or running exposed shall be joi
ned in accord-
ance with manufacturer’s instructions and related sections of this code.
1209.5 Thermal barrier required. 
Radiant floor heating systems shall be provided with a thermal barrier in accord-
ance with Sections 1209.5.1 through 1209.5.4.
Exception: 
Insulation shall not be required in engineered systems where it can be demonstrated that the insulation 
will decrease the efficiency or have a negative effect on the installation.
1209.5.1 Slab
-
on
-
grade installation. 
Radiant piping utilized in slab
-
on
-
grad
e applications shall be provided with 
insulating materials installed beneath the piping having a minimum R
-
value of 5.
1209.5.2 Suspended floor installation. 
In suspended floor applications, insulation shall be installed in the joist 
bay cavity serving the
heating space above and shall consist of materials having a minimum R
-
value of 11.
1209.5.3 Thermal break required. 
A thermal break shall be provided consisting of asphalt expansion joint mate-
rials or similar insulating materials at a point where a heated
slab meets a foundation wall or other conductive slab.
1209.5.4 Thermal barrier material marking. 
Insulating materials utilized in thermal barriers shall be installed 
such that the manufacturer’s R
-
value mark is readily observable upon inspection.
SECTION
MC 
1210
PLASTIC PIPE GROUND
-
SOURCE HEAT PUMP LOOP SYSTEMS
‡‡‡ Chapter 12 was amended by 
Local Law 
77 
of 2023
. This law has an effective
date of June 10, 2023.
CHAPTER 12
HYDRONIC PIPING 
SECTION MC 1201
GENERAL
1201.1 Scope. 
The provisions of this chapter shall govern the construction, installation, alteration and repair of hy-
dronic piping systems. This chapter shall apply to hydronic piping systems that are part of heating, ventilation and air
-
conditioning systems. Such piping systems shall include steam, hot water, chilled water, condenser water, cooling 
coil condensate drain, 
steam condensate and ground
-
source heat pump loop systems. Potable cold and hot water dis-
tribution systems shall be installed in accordance with the 
New York City
Plumbing Code
. 
1201.2 Sizing. 
Piping and piping system components for hydronic systems shall be sized for the 
design requirements
of the system.
1201.3 Standards. 
As an alternative to the provisions of Sections 1202 and 1203, piping shall be designed, installed, 
inspected and tested in accordance with ASME B31.
1 and ASME B31.9, as applicable
. 
SECTION 
MC 
1202
MATERIAL
1202.1 Piping. 
Piping material, other than those contained within this section and conforming with the ASTM stand-
ards listed within this chapter, shall be of an approved type.
Exception: 
Embedded piping regulated by Section 1209, and ground
-
source heat pump loop systems regulated by 
Section 1210.
1202.2 Used existing materials. 
Reused pipe, fittings, valves or other materials shall be clean and free of foreign 
materials.
1202.3 Material rating. 
Materials shall be rated for the operating temperature and pressure of the hydronic system. 
Materials shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards. 
Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior 
of the pipe shall be protected from corrosion and d
egradation.
TABLE 1202.4
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene 
(ABS) plastic pipe
ASTM D 1527; ASTM F 2806
Chlorinated polyvinyl chloride 
(CPVC) plastic pipe
ASTM D 2846; ASTM F 441; 
ASTM F 442
Copper, 
brass, or copper
-
alloy 
pipe
ASTM B 42; ASTM B 43; 
ASTM B 302
Copper, brass, or copper
-
alloy 
tube (Type K, L or M)
ASTM B 75; ASTM B 88; 
ASTM B 135; ASTM B 251
HYDRONIC PIPING
Cross
-
linked 
polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe
ASTM F 1281; CSA
B137.10
Cross
-
linked polyethylene 
(PEX) tubing
ASTM F 876; ASTM F 877
Ductile iron pipe
AWWA C115/A21.15; AWWA 
C151/A21.51 
Polyethylene/aluminum/
polyet
hylene 
(PE
-
AL
-
PE) pressure 
pipe
ASTM F 1282; CSA B137.9
Polypropylene (PP) 
plastic pipe
ASTM F 2389
Polyvinyl chloride (PVC) 
plastic pipe
ASTM D 1785; ASTM D 2241
Raised temperature 
polyethylene (PE
-
RT)
ASTM F 2623; ASTM F 2769
Steel pipe
ASTM A 53/A 53M; ASTM A 
106
Steel tubing
ASTM A 254
1202.5 Pipe fittings. 
Hydronic pipe fittings shall conform to the respective pipe standards or to the standards listed in 
Table 1202.5.
TABLE 1202.5
HYDRONIC PIPE FITTINGS
MATERIAL
STANDARD (see Chapter 15)
Copper, brass, and copper 
alloys
ASME B16.15; ASME B16.18; ASME 
B16.22; 
ASME B16.24; 
ASME 
B16.26; 
ASME B16.51; ASTM F 
1974 
Ductile iron and gray iron
ANSI/AWWA C110/A21.10; 
AWWA C153/A21.53; ASTM A 
126; ASTM A 395; ASTM A 536; 
ASTM F 1476; ASTM F 1548
Malleable iron
ASME B16.3
PE
-
RT fittings
ASTM F 1807; ASTM F 2098; 
ASTM F 2159; ASTM F 2735; 
ASTM F 2769
PEX fittings
ASTM F 877; ASTM F 1807; ASTM 
F 2159
Plastic
ASTM D 2466; ASTM D 2467; 
ASTM F 438; ASTM F 439; ASTM 
F
877; ASTM F 2389; ASTM F 2735
HYDRONIC PIPING
Steel
ASME B16.5; ASME 
B16.9; ASME 
B16.11; ASME B16.28; ASTM A 
53/A 53M; ASTM A 106; ASTM A 
234; ASTM A 420; ASTM A 536; 
ASTM A 395; ASTM F 1476; ASTM 
F 1548
1202.6 Valves. 
Valves shall be constructed of materials that are compatible with the type of piping material and fluids 
in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration compensators. 
Flexible connectors, expansion and vibration 
control devices and fit
tings
, when used, shall protect the components of the hydronic system from damage caused by 
expansion, contraction, transverse movement, angular deflection and vibration,
shall be 
rated for the temperatures 
and pressures of the systems in which the devices
are installed, and shall be compatible with the fluid and all materials 
provided
.
SECTION 
MC 
1203
JOINTS AND CONNECTIONS
1203.1 Approval. 
Joints and connections
, other than those contained in Section 1203 and conforming to the ASTM 
standards listed in Sec
tion 1203,
shall be of an approved type. Joints and connections shall be tight for the pressure 
of the hydronic system.
1203.1.1 Joints between different piping materials. 
Joints between different piping materials shall be 
rated for 
the temperatures and pr
essures of the systems in which the devices are installed and shall be compatible with the 
fluid and all materials provided. 
1203.
1.2 Joints between dissimilar metallic piping materials.
Joints between dissimilar metallic piping mate-
rials shall be provide
d to protect against galvanic corrosion. Such joints shall be 
made with 
dielectric fittings 
conforming to ANSI B16.39 or ASTM F 492, as applicable, shall be rated for the temperatures and pressures of 
the systems in which the devices are installed and shal
l be compatible with the fluid and all materials provided
.
Exception:
Dielectric fittings shall not be required for joints between dissimilar metal piping used within heat 
transfer appliances or equipment when such joints are provided by the appliance or e
quipment manufacturer, 
and such appliance or equipment is connected with isolation valves that are accessible.
1203.2 Preparation of pipe ends. 
Pipe shall be cut square, reamed and chamfered, and shall be free of burrs and 
obstructions. Pipe ends shall hav
e full
-
bore openings and shall not be undercut.
1203.3 Joint preparation and installation. 
Where required by Sections 1203.4 through 1203.14, the preparation and 
installation of brazed, mechanical, soldered, 
solvent
-
cemented
, threaded and welded joints shall comply with Sections 
1203.3.1 through 1203.3.8.
1203.3.1 Brazed joints.
All joints 
shall
be brazed with a 
brazing procedure developed and qualified in accordance 
with the ASME
Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications) or in accord-
ance with 
AWS 
B2.2 Standard for Brazing Procedure and Performance Qualifica
tion
.
1203.3.2 Mechanical joints. 
Mechanical joints shall be installed in accordance with the manufacturer’s instruc-
tions.
1203.3.3 Soldered joints. 
Joint surfaces shall be cleaned. A flux conforming to ASTM B 813 shall be applied. The 
joint shall be solde
red with a solder conforming to ASTM B 32.
1203.3.4 Solvent
-
cemented joints. 
Joint surfaces shall be clean and free of moisture. 
A
primer
, compatible with 
both the piping material and the cement
shall be applied to pipe
-
joint surfaces
, in accordance with t
he manufac-
turer’s requirements
. Joints shall be made while the cement is wet. Solvent cement conforming to the following 
standards shall be applied to all joint surfaces:
1.
ASTM D 2235 for ABS joints.
2.
ASTM F 493 for CPVC joints.
HYDRONIC PIPING
3.
ASTM D 2564 for PVC 
joints.
1203.3.5 Threaded joints. 
Threads shall conform to ASME B1.20.1. Schedule 80 or heavier plastic pipe shall be 
threaded with dies specifically designed for plastic pipe. Thread lubricant, pipe
-
joint compound or tape shall be 
applied on the male threads only and shall be 
compatible
f
or application on the piping material
and fluid
.
1203.3.6 Welded joints.
All joints shall be welded with a welding procedure developed and qualified in accord-
ance with the 
ASME Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications
) or in 
accordance with AWS B2.1 Specifications for Welding Procedure and Performance Qualification.
1203.3.7 Grooved and shouldered mechanical joints. 
Grooved and shouldered mechanical joints shall conform 
to the requirements of ASTM F 1476 and shall be i
nstalled in accordance with the manufacturer’s
instructions.
1203.3.8 Mechanically formed tee fittings. 
Mechanically extracted outlets shall have a height not less than three 
times the thickness of the branch tube wall.
1203.3.8.1 Full flow assurance. 
Bran
ch tubes shall not restrict the flow in the run tube. A dimple/depth stop 
shall be formed in the branch tube to ensure that penetration into the outlet is of the correct depth. For inspection 
purposes, a second dimple shall be placed
1
/
4
inch (6.4 mm) above the first dimple. Dimples shall be aligned 
with the tube run.
1203.3.8.2 Brazed joints. 
Mechanically formed tee fittings shall be brazed in accordance with Section 1203.3.1.
1203.4 ABS plastic pipe. 
Joints between ABS plastic pipe or f
ittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.5 Brass pipe. 
Joints between brass pipe or fittings shall be brazed, mechanical, threaded or welded joints con-
forming to Section 1203.3.
1203.6 Brass tubing. 
Joints bet
ween brass tubing or fittings shall be brazed, mechanical or soldered joints conforming 
to Section 1203.3.
1203.7 Copper or copper
-
alloy pipe. 
Joints between copper or copper
-
alloy pipe or fittings shall be brazed, mechan-
ical, soldered, threaded or welded 
joints conforming to Section 1203.3.
1203.8 Copper or copper
-
alloy tubing. 
Joints between copper or copper
-
alloy tubing or fittings shall be brazed, 
mechanical or soldered joints conforming to Section 1203.3, flared joints conforming to Section 1203.8.1
or
push
-
fit 
joints conforming to Section 1203.8.2.
1203.8.1 Flared joints. 
Flared joints shall be made by a tool designed for that operation.
1203.8.2 Push
-
fit joints. 
Push
-
fit joints shall be installed in accordance with the manufacturer’s instructions.
120
3.9 CPVC plastic pipe.   
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.10 Reserved.
1203.11 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints between cross
-
linked polyethyle
ne plastic tubing 
and fittings shall conform to Sections 1203.11.1 and 1203.11.2. Mechanical joints shall conform to Section 1203.3.
1203.11.1 Compression
-
type fittings. 
Where
compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings 
shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.11.2 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not less 
than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same 
water line.
1203.12 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.13 Steel pipe. 
Joints between steel pipe or fittings shall be mechanical
, threaded or welded 
joints 
conforming to 
Section 1203.3.
1203.14 Steel tubing. 
Joints between steel tubing or fittings shall be mechanical or welded joints conforming to Sec-
tion 1203.3.
HYDRONIC PIPING
1203.15 Polypropylene (PP) plastic. 
Joints between PP plastic pipe and fittings shall comp
ly with Sections 1203.15.1 
and 1203.15.2.
1203.15.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylene fittings, electro
-
fusion polypropylene fittings or by butt
fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1203.15.2 Mechanical and compression sleeve joints. 
Mechanical and compression sleeve joints shal
l be installed 
in accordance with the manufacturer’s instructions.
1203.16 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyethylene 
tubing and fittings shall conform to Sections 1203.16.1 and 1203.16.2. Mechani
cal joints shall conform to Section 
1203.3.
1203.16.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.16.2 PE
-
RT
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 mm) 
of a transition from such metal pipe to PE
-
RT pipe.
1203.17 Polyethylene/aluminum/polyethylene (PE
-
AL
-
PE) pressure pipe. 
Joints between polyethylene/alumi-
num/po
lyethylene pressure pipe and fittings shall conform to Sections 1203.17.1 and 1203.17.2. Mechanical joints 
shall comply with Section 1203.3.
1203.17.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
f
ittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.17.2 PE
-
AL
-
PE
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 
mm) of a transition from such metal pipe to PE
-
AL
-
PE pipe.
1203.18 Cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe. 
Joints 
between cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene pressure pipe and fittings shall conform to 
Sections 1203.18.1 and 1203.18.2. Mecha
nical joints shall comply with Section 1203.3.
1203.18.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.18.2 PEX
-
AL
-
PEX
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches 
(457.2 mm) of a transition from such metal pipe to PEX
-
AL
-
PEX pipe.
SECTION 
MC 
1204
PIPE INSULATION
1204.1 Insulation characteristics. 
Pipe insulation installed in buildings shall conform to the requirements of the 
New 
York City
Energy Conservation Code
,
shall be tested in accordance with ASTM E 84 or UL 723, using the specimen 
preparation and mounting p
rocedures of ASTM E 2231; and shall have a maximum flame spread index of 25 and a 
smoke
-
developed index not exceeding 450. Insulation installed in an air plenum shall comply with Section 602.2.1.
1204.2 Required thickness. 
Hydronic piping shall be insulate
d to the thickness required by the 
New York City
Energy 
Conservation Code.
SECTION 
MC 
1205
VALVES
1205.1 Where required. 
Shutoff valves shall be installed in hydronic piping systems in the locations indicated in 
Sections 1205.1.1 through 1205.1.6.
1205.1.1
Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
HYDRONIC PIPING
Exception: 
Shutoff valves shall not be required where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat 
exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1205.1.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of central utility 
systems, and district
heating and cooling 
systems.
1205.1.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1205.1.4 Pressure
-
reducing valves. 
Shutoff valves shall be installed on both sides of a pressure
-
reduc
ing valve.
1205.1.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a hydronic system such as pumps, air separators, 
metering devices and si
milar equipment.
1205.1.6 Expansion tanks.
Lockable shutoff
valves shall be installed at connections to 
all
expansion tanks.
Valves shall be locked in the open position.
1205.2 Reduced pressure. 
A pressure relief valve shall be installed on the 
low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system design. 
The valve shall be installed in accordance with Section 1006.
SECTION 
MC 
1206
PIPING INSTALLATION
1
206.1 General. 
Piping, valves, fittings and connections shall be installed in accordance with the conditions of ap-
proval.
1206.2 System drain down. 
Hydronic piping systems shall be designed and installed to permit the system to be 
drained. Where the system
drains to the plumbing drainage system, the installation shall conform to the requirements 
of the 
New York City
Plumbing Code.
Exception: 
The buried portions of systems embedded underground.
1206.3 Protection of potable water. 
The potable water system sha
ll be protected from backflow in accordance with 
the 
New York City
Plumbing Code.
1206.4 Pipe penetrations. 
Openings for pipe penetrations in walls, floors or ceilings shall be larger than the penetrat-
ing pipe. Openings through concrete or masonry building
elements shall be sleeved. The annular space surrounding 
pipe penetrations shall be protected in accordance with the 
New York City
Building Code.
1206.5 Clearance to combustibles. 
A pipe in a hydronic piping system in which the exterior temperature exceed
s 
250°F (
121.1
°C) shall have a minimum clearance of 1 inch (25.4 mm) to combustible materials.
1206.6 Contact with building material. 
A hydronic piping system shall not be in direct contact with building mate-
rials that cause the piping material to degrade 
or corrode, or that interfere with the operation of the system.
1206.7 Water hammer. 
The flow velocity of the hydronic piping system shall be controlled to reduce the possibility 
of water hammer. Where a quick
-
closing valve creates water hammer, an 
enginee
red
water
-
hammer arrestor shall be 
installed. The arrestor shall be located within a range as specified by the manufacturer of the quick
-
closing valve.
1206.8 Steam piping pitch. 
Steam piping shall be installed to drain to the boiler or the steam trap. Ste
am systems 
shall not have drip pockets that reduce the capacity of the steam piping.
1206.9 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains and stresses in the pipe. 
Provisions shall be made to protect piping from damag
e resulting from expansion, contraction and structural settle-
ment. Piping shall be installed so as to avoid structural stresses or strains within building components.
1206.9.1 Flood hazard. 
Piping located in flood hazard areas 
shall comply with Appendix G
of 
the 
New York City 
Building Code
.
HYDRONIC PIPING
1206.10 Pipe support. 
Pipe shall be supported in accordance with Section 305.
Seismic supports shall be provided 
where required by the 
New York City Building Code.
1206.11 Condensation. 
Provisions shall be made to prevent the formation of condensation on the exterior of piping.
SECTION 
MC 
1207
TRANSFER FLUID
1207.1 Flash point. 
The
flash point of transfer fluid in a hydronic piping system shall be not less than 50°F (10°C) 
above the maximum system operating temperature.
1207.2 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
SECTION 
MC 
1208
TESTS
1208.1 General. 
Hydronic piping systems 
other than ground
-
source heat pump loop systems 
shall be tested hydro-
statically at one and one
half times the system design 
operating 
pressure, but not less than 100 psi (689 kPa). The 
duration of each 
test shall be not less than
2 hours. Ground
-
source heat pump loop systems shall be tested in accord-
ance with Section 1210.10.
SECTION 
MC 
1209
EMBEDDED PIPING
1209.1 Materials. 
Embedded piping
shall be plastic pipe or tubing
, in accordance with Section 1202
,
rated at 100 psi 
(689.5 kPa) at 180°F (82.2°C).
1209.2 Pressurizing during installation. 
Piping to be embedded in concrete shall be pressure tested prior to pouring 
concrete. During pouring, the pipe shall be maintained at the proposed operating pressure
.
1209.3 Embedded joints. 
Joints of pipe or tubing that are embedded in a portion of the building, such as concrete or 
plaster, shall be thermally
-
fused.
1209.4 Not embedded related piping. 
Joints of other piping in cavities or running exposed shall be joi
ned in accord-
ance with manufacturer’s instructions and related sections of this code.
1209.5 Thermal barrier required. 
Radiant floor heating systems shall be provided with a thermal barrier in accord-
ance with Sections 1209.5.1 through 1209.5.4.
Exception: 
Insulation shall not be required in engineered systems where it can be demonstrated that the insulation 
will decrease the efficiency or have a negative effect on the installation.
1209.5.1 Slab
-
on
-
grade installation. 
Radiant piping utilized in slab
-
on
-
grad
e applications shall be provided with 
insulating materials installed beneath the piping having a minimum R
-
value of 5.
1209.5.2 Suspended floor installation. 
In suspended floor applications, insulation shall be installed in the joist 
bay cavity serving the
heating space above and shall consist of materials having a minimum R
-
value of 11.
1209.5.3 Thermal break required. 
A thermal break shall be provided consisting of asphalt expansion joint mate-
rials or similar insulating materials at a point where a heated
slab meets a foundation wall or other conductive slab.
1209.5.4 Thermal barrier material marking. 
Insulating materials utilized in thermal barriers shall be installed 
such that the manufacturer’s R
-
value mark is readily observable upon inspection.
SECTION
MC 
1210
PLASTIC PIPE GROUND
-
SOURCE HEAT PUMP LOOP SYSTEMS
HYDRONIC PIPING
1210.1 Ground
-
source heat pump
-
loop water piping. 
Ground
-
source heat pump ground
-
loop piping and tubing 
material for water
-
based systems shall conform to the standards cited in this section.
1210.2
Used materials. 
Reused pipe, fittings, valves, and other materials shall not be permitted in ground
-
source heat 
pump loop systems.
1210.3 Material rating. 
Pipe and tubing shall be rated for the operating temperature and pressure of the ground
-
source heat 
pump loop system. Fittings shall be suitable for the pressure applications and recommended by the man-
ufacturer for installation with the pipe and tubing material installed. Where used underground, materials shall be suit-
able for burial.
1210.4 Piping and t
ubing materials standards. 
Ground
-
source heat pump ground
-
loop pipe and tubing shall con-
form to the standards listed in Table 1210.4.
TABLE 1210.4
GROUND
-
SOURCE LOOP PIPE
MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl chloride 
(CPVC)
ASTM D 
2846; ASTM F 
441; ASTM F 442
Cross
-
linked polyethylene (PEX)
ASTM F 876; ASTM F 877; 
CSA B137.5
Polyethylene/aluminum/polyethylen
e (PE
-
AL
-
PE) pressure pipe
ASTM F 1282; CSA B137.9
High
-
density polyethylene (HDPE)
ASTM D 2737; ASTM D 
3035; ASTM F 
714; AWWA 
C901; CSA B137.1; CSA 
C448; NSF 358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl chloride (PVC)
ASTM D 1785; ASTM D 
2241
Raised temperature polyethylene 
(PE
-
RT)
ASTM F 2623
1210.5 Fittings. 
Ground
-
source heat pump pipe fittings shall conform to the standards listed in Table 1210.5 and, if 
installed underground, shall be suitable for burial. 
TABLE 1210.5
GROUND
-
SOURCE LOOP PIPE FITTINGS
PIPE MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl 
chloride (CPVC)
ASTM D 2846; ASTM F 437; ASTM F 
438; ASTM F 439; CSA B137.6
Cross
-
linked 
polyethylene (PEX)
ASTM F 877; ASTM F 1807; ASTM F 
1960; ASTM F 2080; ASTM F 2159; 
ASTM F 2434; CSA B137.5
Polyethylene/aluminum/
polyethylene (PE
-
AL
-
PE)
ASTM F 1282; ASTM F 2434; CSA 
B137.9
‡‡‡ Chapter 12 was amended by 
Local Law 
77 
of 2023
. This law has an effective
date of June 10, 2023.
CHAPTER 12
HYDRONIC PIPING 
SECTION MC 1201
GENERAL
1201.1 Scope. 
The provisions of this chapter shall govern the construction, installation, alteration and repair of hy-
dronic piping systems. This chapter shall apply to hydronic piping systems that are part of heating, ventilation and air
-
conditioning systems. Such piping systems shall include steam, hot water, chilled water, condenser water, cooling 
coil condensate drain, 
steam condensate and ground
-
source heat pump loop systems. Potable cold and hot water dis-
tribution systems shall be installed in accordance with the 
New York City
Plumbing Code
. 
1201.2 Sizing. 
Piping and piping system components for hydronic systems shall be sized for the 
design requirements
of the system.
1201.3 Standards. 
As an alternative to the provisions of Sections 1202 and 1203, piping shall be designed, installed, 
inspected and tested in accordance with ASME B31.
1 and ASME B31.9, as applicable
. 
SECTION 
MC 
1202
MATERIAL
1202.1 Piping. 
Piping material, other than those contained within this section and conforming with the ASTM stand-
ards listed within this chapter, shall be of an approved type.
Exception: 
Embedded piping regulated by Section 1209, and ground
-
source heat pump loop systems regulated by 
Section 1210.
1202.2 Used existing materials. 
Reused pipe, fittings, valves or other materials shall be clean and free of foreign 
materials.
1202.3 Material rating. 
Materials shall be rated for the operating temperature and pressure of the hydronic system. 
Materials shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards. 
Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior 
of the pipe shall be protected from corrosion and d
egradation.
TABLE 1202.4
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene 
(ABS) plastic pipe
ASTM D 1527; ASTM F 2806
Chlorinated polyvinyl chloride 
(CPVC) plastic pipe
ASTM D 2846; ASTM F 441; 
ASTM F 442
Copper, 
brass, or copper
-
alloy 
pipe
ASTM B 42; ASTM B 43; 
ASTM B 302
Copper, brass, or copper
-
alloy 
tube (Type K, L or M)
ASTM B 75; ASTM B 88; 
ASTM B 135; ASTM B 251
HYDRONIC PIPING
Cross
-
linked 
polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe
ASTM F 1281; CSA
B137.10
Cross
-
linked polyethylene 
(PEX) tubing
ASTM F 876; ASTM F 877
Ductile iron pipe
AWWA C115/A21.15; AWWA 
C151/A21.51 
Polyethylene/aluminum/
polyet
hylene 
(PE
-
AL
-
PE) pressure 
pipe
ASTM F 1282; CSA B137.9
Polypropylene (PP) 
plastic pipe
ASTM F 2389
Polyvinyl chloride (PVC) 
plastic pipe
ASTM D 1785; ASTM D 2241
Raised temperature 
polyethylene (PE
-
RT)
ASTM F 2623; ASTM F 2769
Steel pipe
ASTM A 53/A 53M; ASTM A 
106
Steel tubing
ASTM A 254
1202.5 Pipe fittings. 
Hydronic pipe fittings shall conform to the respective pipe standards or to the standards listed in 
Table 1202.5.
TABLE 1202.5
HYDRONIC PIPE FITTINGS
MATERIAL
STANDARD (see Chapter 15)
Copper, brass, and copper 
alloys
ASME B16.15; ASME B16.18; ASME 
B16.22; 
ASME B16.24; 
ASME 
B16.26; 
ASME B16.51; ASTM F 
1974 
Ductile iron and gray iron
ANSI/AWWA C110/A21.10; 
AWWA C153/A21.53; ASTM A 
126; ASTM A 395; ASTM A 536; 
ASTM F 1476; ASTM F 1548
Malleable iron
ASME B16.3
PE
-
RT fittings
ASTM F 1807; ASTM F 2098; 
ASTM F 2159; ASTM F 2735; 
ASTM F 2769
PEX fittings
ASTM F 877; ASTM F 1807; ASTM 
F 2159
Plastic
ASTM D 2466; ASTM D 2467; 
ASTM F 438; ASTM F 439; ASTM 
F
877; ASTM F 2389; ASTM F 2735
HYDRONIC PIPING
Steel
ASME B16.5; ASME 
B16.9; ASME 
B16.11; ASME B16.28; ASTM A 
53/A 53M; ASTM A 106; ASTM A 
234; ASTM A 420; ASTM A 536; 
ASTM A 395; ASTM F 1476; ASTM 
F 1548
1202.6 Valves. 
Valves shall be constructed of materials that are compatible with the type of piping material and fluids 
in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration compensators. 
Flexible connectors, expansion and vibration 
control devices and fit
tings
, when used, shall protect the components of the hydronic system from damage caused by 
expansion, contraction, transverse movement, angular deflection and vibration,
shall be 
rated for the temperatures 
and pressures of the systems in which the devices
are installed, and shall be compatible with the fluid and all materials 
provided
.
SECTION 
MC 
1203
JOINTS AND CONNECTIONS
1203.1 Approval. 
Joints and connections
, other than those contained in Section 1203 and conforming to the ASTM 
standards listed in Sec
tion 1203,
shall be of an approved type. Joints and connections shall be tight for the pressure 
of the hydronic system.
1203.1.1 Joints between different piping materials. 
Joints between different piping materials shall be 
rated for 
the temperatures and pr
essures of the systems in which the devices are installed and shall be compatible with the 
fluid and all materials provided. 
1203.
1.2 Joints between dissimilar metallic piping materials.
Joints between dissimilar metallic piping mate-
rials shall be provide
d to protect against galvanic corrosion. Such joints shall be 
made with 
dielectric fittings 
conforming to ANSI B16.39 or ASTM F 492, as applicable, shall be rated for the temperatures and pressures of 
the systems in which the devices are installed and shal
l be compatible with the fluid and all materials provided
.
Exception:
Dielectric fittings shall not be required for joints between dissimilar metal piping used within heat 
transfer appliances or equipment when such joints are provided by the appliance or e
quipment manufacturer, 
and such appliance or equipment is connected with isolation valves that are accessible.
1203.2 Preparation of pipe ends. 
Pipe shall be cut square, reamed and chamfered, and shall be free of burrs and 
obstructions. Pipe ends shall hav
e full
-
bore openings and shall not be undercut.
1203.3 Joint preparation and installation. 
Where required by Sections 1203.4 through 1203.14, the preparation and 
installation of brazed, mechanical, soldered, 
solvent
-
cemented
, threaded and welded joints shall comply with Sections 
1203.3.1 through 1203.3.8.
1203.3.1 Brazed joints.
All joints 
shall
be brazed with a 
brazing procedure developed and qualified in accordance 
with the ASME
Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications) or in accord-
ance with 
AWS 
B2.2 Standard for Brazing Procedure and Performance Qualifica
tion
.
1203.3.2 Mechanical joints. 
Mechanical joints shall be installed in accordance with the manufacturer’s instruc-
tions.
1203.3.3 Soldered joints. 
Joint surfaces shall be cleaned. A flux conforming to ASTM B 813 shall be applied. The 
joint shall be solde
red with a solder conforming to ASTM B 32.
1203.3.4 Solvent
-
cemented joints. 
Joint surfaces shall be clean and free of moisture. 
A
primer
, compatible with 
both the piping material and the cement
shall be applied to pipe
-
joint surfaces
, in accordance with t
he manufac-
turer’s requirements
. Joints shall be made while the cement is wet. Solvent cement conforming to the following 
standards shall be applied to all joint surfaces:
1.
ASTM D 2235 for ABS joints.
2.
ASTM F 493 for CPVC joints.
HYDRONIC PIPING
3.
ASTM D 2564 for PVC 
joints.
1203.3.5 Threaded joints. 
Threads shall conform to ASME B1.20.1. Schedule 80 or heavier plastic pipe shall be 
threaded with dies specifically designed for plastic pipe. Thread lubricant, pipe
-
joint compound or tape shall be 
applied on the male threads only and shall be 
compatible
f
or application on the piping material
and fluid
.
1203.3.6 Welded joints.
All joints shall be welded with a welding procedure developed and qualified in accord-
ance with the 
ASME Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications
) or in 
accordance with AWS B2.1 Specifications for Welding Procedure and Performance Qualification.
1203.3.7 Grooved and shouldered mechanical joints. 
Grooved and shouldered mechanical joints shall conform 
to the requirements of ASTM F 1476 and shall be i
nstalled in accordance with the manufacturer’s
instructions.
1203.3.8 Mechanically formed tee fittings. 
Mechanically extracted outlets shall have a height not less than three 
times the thickness of the branch tube wall.
1203.3.8.1 Full flow assurance. 
Bran
ch tubes shall not restrict the flow in the run tube. A dimple/depth stop 
shall be formed in the branch tube to ensure that penetration into the outlet is of the correct depth. For inspection 
purposes, a second dimple shall be placed
1
/
4
inch (6.4 mm) above the first dimple. Dimples shall be aligned 
with the tube run.
1203.3.8.2 Brazed joints. 
Mechanically formed tee fittings shall be brazed in accordance with Section 1203.3.1.
1203.4 ABS plastic pipe. 
Joints between ABS plastic pipe or f
ittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.5 Brass pipe. 
Joints between brass pipe or fittings shall be brazed, mechanical, threaded or welded joints con-
forming to Section 1203.3.
1203.6 Brass tubing. 
Joints bet
ween brass tubing or fittings shall be brazed, mechanical or soldered joints conforming 
to Section 1203.3.
1203.7 Copper or copper
-
alloy pipe. 
Joints between copper or copper
-
alloy pipe or fittings shall be brazed, mechan-
ical, soldered, threaded or welded 
joints conforming to Section 1203.3.
1203.8 Copper or copper
-
alloy tubing. 
Joints between copper or copper
-
alloy tubing or fittings shall be brazed, 
mechanical or soldered joints conforming to Section 1203.3, flared joints conforming to Section 1203.8.1
or
push
-
fit 
joints conforming to Section 1203.8.2.
1203.8.1 Flared joints. 
Flared joints shall be made by a tool designed for that operation.
1203.8.2 Push
-
fit joints. 
Push
-
fit joints shall be installed in accordance with the manufacturer’s instructions.
120
3.9 CPVC plastic pipe.   
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.10 Reserved.
1203.11 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints between cross
-
linked polyethyle
ne plastic tubing 
and fittings shall conform to Sections 1203.11.1 and 1203.11.2. Mechanical joints shall conform to Section 1203.3.
1203.11.1 Compression
-
type fittings. 
Where
compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings 
shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.11.2 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not less 
than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same 
water line.
1203.12 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.13 Steel pipe. 
Joints between steel pipe or fittings shall be mechanical
, threaded or welded 
joints 
conforming to 
Section 1203.3.
1203.14 Steel tubing. 
Joints between steel tubing or fittings shall be mechanical or welded joints conforming to Sec-
tion 1203.3.
HYDRONIC PIPING
1203.15 Polypropylene (PP) plastic. 
Joints between PP plastic pipe and fittings shall comp
ly with Sections 1203.15.1 
and 1203.15.2.
1203.15.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylene fittings, electro
-
fusion polypropylene fittings or by butt
fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1203.15.2 Mechanical and compression sleeve joints. 
Mechanical and compression sleeve joints shal
l be installed 
in accordance with the manufacturer’s instructions.
1203.16 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyethylene 
tubing and fittings shall conform to Sections 1203.16.1 and 1203.16.2. Mechani
cal joints shall conform to Section 
1203.3.
1203.16.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.16.2 PE
-
RT
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 mm) 
of a transition from such metal pipe to PE
-
RT pipe.
1203.17 Polyethylene/aluminum/polyethylene (PE
-
AL
-
PE) pressure pipe. 
Joints between polyethylene/alumi-
num/po
lyethylene pressure pipe and fittings shall conform to Sections 1203.17.1 and 1203.17.2. Mechanical joints 
shall comply with Section 1203.3.
1203.17.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
f
ittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.17.2 PE
-
AL
-
PE
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 
mm) of a transition from such metal pipe to PE
-
AL
-
PE pipe.
1203.18 Cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe. 
Joints 
between cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene pressure pipe and fittings shall conform to 
Sections 1203.18.1 and 1203.18.2. Mecha
nical joints shall comply with Section 1203.3.
1203.18.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.18.2 PEX
-
AL
-
PEX
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches 
(457.2 mm) of a transition from such metal pipe to PEX
-
AL
-
PEX pipe.
SECTION 
MC 
1204
PIPE INSULATION
1204.1 Insulation characteristics. 
Pipe insulation installed in buildings shall conform to the requirements of the 
New 
York City
Energy Conservation Code
,
shall be tested in accordance with ASTM E 84 or UL 723, using the specimen 
preparation and mounting p
rocedures of ASTM E 2231; and shall have a maximum flame spread index of 25 and a 
smoke
-
developed index not exceeding 450. Insulation installed in an air plenum shall comply with Section 602.2.1.
1204.2 Required thickness. 
Hydronic piping shall be insulate
d to the thickness required by the 
New York City
Energy 
Conservation Code.
SECTION 
MC 
1205
VALVES
1205.1 Where required. 
Shutoff valves shall be installed in hydronic piping systems in the locations indicated in 
Sections 1205.1.1 through 1205.1.6.
1205.1.1
Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
HYDRONIC PIPING
Exception: 
Shutoff valves shall not be required where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat 
exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1205.1.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of central utility 
systems, and district
heating and cooling 
systems.
1205.1.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1205.1.4 Pressure
-
reducing valves. 
Shutoff valves shall be installed on both sides of a pressure
-
reduc
ing valve.
1205.1.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a hydronic system such as pumps, air separators, 
metering devices and si
milar equipment.
1205.1.6 Expansion tanks.
Lockable shutoff
valves shall be installed at connections to 
all
expansion tanks.
Valves shall be locked in the open position.
1205.2 Reduced pressure. 
A pressure relief valve shall be installed on the 
low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system design. 
The valve shall be installed in accordance with Section 1006.
SECTION 
MC 
1206
PIPING INSTALLATION
1
206.1 General. 
Piping, valves, fittings and connections shall be installed in accordance with the conditions of ap-
proval.
1206.2 System drain down. 
Hydronic piping systems shall be designed and installed to permit the system to be 
drained. Where the system
drains to the plumbing drainage system, the installation shall conform to the requirements 
of the 
New York City
Plumbing Code.
Exception: 
The buried portions of systems embedded underground.
1206.3 Protection of potable water. 
The potable water system sha
ll be protected from backflow in accordance with 
the 
New York City
Plumbing Code.
1206.4 Pipe penetrations. 
Openings for pipe penetrations in walls, floors or ceilings shall be larger than the penetrat-
ing pipe. Openings through concrete or masonry building
elements shall be sleeved. The annular space surrounding 
pipe penetrations shall be protected in accordance with the 
New York City
Building Code.
1206.5 Clearance to combustibles. 
A pipe in a hydronic piping system in which the exterior temperature exceed
s 
250°F (
121.1
°C) shall have a minimum clearance of 1 inch (25.4 mm) to combustible materials.
1206.6 Contact with building material. 
A hydronic piping system shall not be in direct contact with building mate-
rials that cause the piping material to degrade 
or corrode, or that interfere with the operation of the system.
1206.7 Water hammer. 
The flow velocity of the hydronic piping system shall be controlled to reduce the possibility 
of water hammer. Where a quick
-
closing valve creates water hammer, an 
enginee
red
water
-
hammer arrestor shall be 
installed. The arrestor shall be located within a range as specified by the manufacturer of the quick
-
closing valve.
1206.8 Steam piping pitch. 
Steam piping shall be installed to drain to the boiler or the steam trap. Ste
am systems 
shall not have drip pockets that reduce the capacity of the steam piping.
1206.9 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains and stresses in the pipe. 
Provisions shall be made to protect piping from damag
e resulting from expansion, contraction and structural settle-
ment. Piping shall be installed so as to avoid structural stresses or strains within building components.
1206.9.1 Flood hazard. 
Piping located in flood hazard areas 
shall comply with Appendix G
of 
the 
New York City 
Building Code
.
HYDRONIC PIPING
1206.10 Pipe support. 
Pipe shall be supported in accordance with Section 305.
Seismic supports shall be provided 
where required by the 
New York City Building Code.
1206.11 Condensation. 
Provisions shall be made to prevent the formation of condensation on the exterior of piping.
SECTION 
MC 
1207
TRANSFER FLUID
1207.1 Flash point. 
The
flash point of transfer fluid in a hydronic piping system shall be not less than 50°F (10°C) 
above the maximum system operating temperature.
1207.2 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
SECTION 
MC 
1208
TESTS
1208.1 General. 
Hydronic piping systems 
other than ground
-
source heat pump loop systems 
shall be tested hydro-
statically at one and one
half times the system design 
operating 
pressure, but not less than 100 psi (689 kPa). The 
duration of each 
test shall be not less than
2 hours. Ground
-
source heat pump loop systems shall be tested in accord-
ance with Section 1210.10.
SECTION 
MC 
1209
EMBEDDED PIPING
1209.1 Materials. 
Embedded piping
shall be plastic pipe or tubing
, in accordance with Section 1202
,
rated at 100 psi 
(689.5 kPa) at 180°F (82.2°C).
1209.2 Pressurizing during installation. 
Piping to be embedded in concrete shall be pressure tested prior to pouring 
concrete. During pouring, the pipe shall be maintained at the proposed operating pressure
.
1209.3 Embedded joints. 
Joints of pipe or tubing that are embedded in a portion of the building, such as concrete or 
plaster, shall be thermally
-
fused.
1209.4 Not embedded related piping. 
Joints of other piping in cavities or running exposed shall be joi
ned in accord-
ance with manufacturer’s instructions and related sections of this code.
1209.5 Thermal barrier required. 
Radiant floor heating systems shall be provided with a thermal barrier in accord-
ance with Sections 1209.5.1 through 1209.5.4.
Exception: 
Insulation shall not be required in engineered systems where it can be demonstrated that the insulation 
will decrease the efficiency or have a negative effect on the installation.
1209.5.1 Slab
-
on
-
grade installation. 
Radiant piping utilized in slab
-
on
-
grad
e applications shall be provided with 
insulating materials installed beneath the piping having a minimum R
-
value of 5.
1209.5.2 Suspended floor installation. 
In suspended floor applications, insulation shall be installed in the joist 
bay cavity serving the
heating space above and shall consist of materials having a minimum R
-
value of 11.
1209.5.3 Thermal break required. 
A thermal break shall be provided consisting of asphalt expansion joint mate-
rials or similar insulating materials at a point where a heated
slab meets a foundation wall or other conductive slab.
1209.5.4 Thermal barrier material marking. 
Insulating materials utilized in thermal barriers shall be installed 
such that the manufacturer’s R
-
value mark is readily observable upon inspection.
SECTION
MC 
1210
PLASTIC PIPE GROUND
-
SOURCE HEAT PUMP LOOP SYSTEMS
HYDRONIC PIPING
1210.1 Ground
-
source heat pump
-
loop water piping. 
Ground
-
source heat pump ground
-
loop piping and tubing 
material for water
-
based systems shall conform to the standards cited in this section.
1210.2
Used materials. 
Reused pipe, fittings, valves, and other materials shall not be permitted in ground
-
source heat 
pump loop systems.
1210.3 Material rating. 
Pipe and tubing shall be rated for the operating temperature and pressure of the ground
-
source heat 
pump loop system. Fittings shall be suitable for the pressure applications and recommended by the man-
ufacturer for installation with the pipe and tubing material installed. Where used underground, materials shall be suit-
able for burial.
1210.4 Piping and t
ubing materials standards. 
Ground
-
source heat pump ground
-
loop pipe and tubing shall con-
form to the standards listed in Table 1210.4.
TABLE 1210.4
GROUND
-
SOURCE LOOP PIPE
MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl chloride 
(CPVC)
ASTM D 
2846; ASTM F 
441; ASTM F 442
Cross
-
linked polyethylene (PEX)
ASTM F 876; ASTM F 877; 
CSA B137.5
Polyethylene/aluminum/polyethylen
e (PE
-
AL
-
PE) pressure pipe
ASTM F 1282; CSA B137.9
High
-
density polyethylene (HDPE)
ASTM D 2737; ASTM D 
3035; ASTM F 
714; AWWA 
C901; CSA B137.1; CSA 
C448; NSF 358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl chloride (PVC)
ASTM D 1785; ASTM D 
2241
Raised temperature polyethylene 
(PE
-
RT)
ASTM F 2623
1210.5 Fittings. 
Ground
-
source heat pump pipe fittings shall conform to the standards listed in Table 1210.5 and, if 
installed underground, shall be suitable for burial. 
TABLE 1210.5
GROUND
-
SOURCE LOOP PIPE FITTINGS
PIPE MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl 
chloride (CPVC)
ASTM D 2846; ASTM F 437; ASTM F 
438; ASTM F 439; CSA B137.6
Cross
-
linked 
polyethylene (PEX)
ASTM F 877; ASTM F 1807; ASTM F 
1960; ASTM F 2080; ASTM F 2159; 
ASTM F 2434; CSA B137.5
Polyethylene/aluminum/
polyethylene (PE
-
AL
-
PE)
ASTM F 1282; ASTM F 2434; CSA 
B137.9
HYDRONIC PIPING
High Density 
Polyethylene (HDPE)
ASTM D 2683; ASTM D 3261; ASTM 
F 1055; CSA B137.1; CSA C448; NSF 
358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl 
chloride 
(PVC)
ASTM D 2464; ASTM D 2466; ASTM 
D 2467; CSA B137.2; CSA B137.3
Raised temperature 
polyethylene (PE
-
RT)
ASTM D 3261; ASTM F 1807; ASTM 
F 2159; CSA B137.1
1210.6 Joints. 
Joints and connections, 
other than those covered by Section 1210 and co
nforming to the ASTM stand-
ards listed therein,
shall be of an approved type. Joints and connections shall be tight for the pressure of the ground
-
source loop system. Joints used underground shall be in accordance with manufacturer’s instructions for buried
appli-
cations.
1210.6.1 Joints between different piping materials. 
Joints between different piping materials shall be made with 
transition fittings compatible with both materials and the fluid contained within the system. Transition fittings must 
be used i
n accordance with manufacturer’s instructions.
1210.6.1.1 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not 
less than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same water line.
1210.6.2 Prep
aration of pipe ends. 
Pipe shall be cut square, be reamed, and be free of burrs and obstructions. 
CPVC, PE, and PVC pipe shall be chamfered. Pipe ends shall have full
-
bore openings and shall not be undercut.
1210.6.3 Joint preparation and installation. 
Whe
re required by Sections 1210.6.4 through 1210.6.6, the prepa-
ration and installation of mechanical and thermoplastic
-
welded joints shall comply with Sections 1210.6.3.1 and 
1210.6.3.2.
1210.6.3.1 Mechanical joints. 
Mechanical joints shall be installed in ac
cordance with the manufacturer’s in-
structions.
1210.6.3.2 Thermoplastic
-
welded joints. 
Joint surfaces for thermoplastic
-
welded joints shall be cleaned by a 
procedure in accordance with the manufacturer’s instructions. Joints shall be welded in accordance w
ith the 
manufacturer’s instructions.
1210.6.4 CPVC plastic pipe. 
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded 
joints complying with Section 1203.3.
‡‡‡
1210.6.5 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints bet
ween cross
-
linked polyethylene plastic 
tubing and fittings shall comply with Section 1210.6.5.1. Mechanical joints shall comply with Section 1210.6.3.
1210.6.5.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
r
ings, 
the fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1210.6.6 Polyethylene plastic pipe and tubing for ground
-
source heat pump loop systems. 
Joints between 
polyethylene plastic pipe and tubing or fittings for 
ground
-
source heat pump loop systems shall be heat fusion 
joints complying with Section 1210.6.6.1, electrofusion joints complying with Section 1210.6.6.2, or stab
-
type 
insertion joints complying with Section 1210.6.6.3.
1210.6.6.1 Heat
-
fusion joints. 
Joints shall be of the socket
-
fusion, saddle
-
fusion or butt
-
fusion type, joined in 
accordance with ASTM D 2657. Joint surfaces shall be clean and free from moisture. Joint surfaces shall be 
heated to melt temperatures and joi
ned. The joint shall be undisturbed until cool. Fittings shall be manufactured 
in accordance with ASTM D 2683 or ASTM D 3261.
1210.6.6.2 Electrofusion joints. 
Joints shall be of the electrofusion type. Joint surfaces shall be clean and free 
from moisture, 
and scoured to expose virgin resin. Joint surfaces shall be heated to melt temperatures for the 
‡‡‡ Chapter 12 was amended by 
Local Law 
77 
of 2023
. This law has an effective
date of June 10, 2023.
CHAPTER 12
HYDRONIC PIPING 
SECTION MC 1201
GENERAL
1201.1 Scope. 
The provisions of this chapter shall govern the construction, installation, alteration and repair of hy-
dronic piping systems. This chapter shall apply to hydronic piping systems that are part of heating, ventilation and air
-
conditioning systems. Such piping systems shall include steam, hot water, chilled water, condenser water, cooling 
coil condensate drain, 
steam condensate and ground
-
source heat pump loop systems. Potable cold and hot water dis-
tribution systems shall be installed in accordance with the 
New York City
Plumbing Code
. 
1201.2 Sizing. 
Piping and piping system components for hydronic systems shall be sized for the 
design requirements
of the system.
1201.3 Standards. 
As an alternative to the provisions of Sections 1202 and 1203, piping shall be designed, installed, 
inspected and tested in accordance with ASME B31.
1 and ASME B31.9, as applicable
. 
SECTION 
MC 
1202
MATERIAL
1202.1 Piping. 
Piping material, other than those contained within this section and conforming with the ASTM stand-
ards listed within this chapter, shall be of an approved type.
Exception: 
Embedded piping regulated by Section 1209, and ground
-
source heat pump loop systems regulated by 
Section 1210.
1202.2 Used existing materials. 
Reused pipe, fittings, valves or other materials shall be clean and free of foreign 
materials.
1202.3 Material rating. 
Materials shall be rated for the operating temperature and pressure of the hydronic system. 
Materials shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards. 
Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior 
of the pipe shall be protected from corrosion and d
egradation.
TABLE 1202.4
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene 
(ABS) plastic pipe
ASTM D 1527; ASTM F 2806
Chlorinated polyvinyl chloride 
(CPVC) plastic pipe
ASTM D 2846; ASTM F 441; 
ASTM F 442
Copper, 
brass, or copper
-
alloy 
pipe
ASTM B 42; ASTM B 43; 
ASTM B 302
Copper, brass, or copper
-
alloy 
tube (Type K, L or M)
ASTM B 75; ASTM B 88; 
ASTM B 135; ASTM B 251
HYDRONIC PIPING
Cross
-
linked 
polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe
ASTM F 1281; CSA
B137.10
Cross
-
linked polyethylene 
(PEX) tubing
ASTM F 876; ASTM F 877
Ductile iron pipe
AWWA C115/A21.15; AWWA 
C151/A21.51 
Polyethylene/aluminum/
polyet
hylene 
(PE
-
AL
-
PE) pressure 
pipe
ASTM F 1282; CSA B137.9
Polypropylene (PP) 
plastic pipe
ASTM F 2389
Polyvinyl chloride (PVC) 
plastic pipe
ASTM D 1785; ASTM D 2241
Raised temperature 
polyethylene (PE
-
RT)
ASTM F 2623; ASTM F 2769
Steel pipe
ASTM A 53/A 53M; ASTM A 
106
Steel tubing
ASTM A 254
1202.5 Pipe fittings. 
Hydronic pipe fittings shall conform to the respective pipe standards or to the standards listed in 
Table 1202.5.
TABLE 1202.5
HYDRONIC PIPE FITTINGS
MATERIAL
STANDARD (see Chapter 15)
Copper, brass, and copper 
alloys
ASME B16.15; ASME B16.18; ASME 
B16.22; 
ASME B16.24; 
ASME 
B16.26; 
ASME B16.51; ASTM F 
1974 
Ductile iron and gray iron
ANSI/AWWA C110/A21.10; 
AWWA C153/A21.53; ASTM A 
126; ASTM A 395; ASTM A 536; 
ASTM F 1476; ASTM F 1548
Malleable iron
ASME B16.3
PE
-
RT fittings
ASTM F 1807; ASTM F 2098; 
ASTM F 2159; ASTM F 2735; 
ASTM F 2769
PEX fittings
ASTM F 877; ASTM F 1807; ASTM 
F 2159
Plastic
ASTM D 2466; ASTM D 2467; 
ASTM F 438; ASTM F 439; ASTM 
F
877; ASTM F 2389; ASTM F 2735
HYDRONIC PIPING
Steel
ASME B16.5; ASME 
B16.9; ASME 
B16.11; ASME B16.28; ASTM A 
53/A 53M; ASTM A 106; ASTM A 
234; ASTM A 420; ASTM A 536; 
ASTM A 395; ASTM F 1476; ASTM 
F 1548
1202.6 Valves. 
Valves shall be constructed of materials that are compatible with the type of piping material and fluids 
in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration compensators. 
Flexible connectors, expansion and vibration 
control devices and fit
tings
, when used, shall protect the components of the hydronic system from damage caused by 
expansion, contraction, transverse movement, angular deflection and vibration,
shall be 
rated for the temperatures 
and pressures of the systems in which the devices
are installed, and shall be compatible with the fluid and all materials 
provided
.
SECTION 
MC 
1203
JOINTS AND CONNECTIONS
1203.1 Approval. 
Joints and connections
, other than those contained in Section 1203 and conforming to the ASTM 
standards listed in Sec
tion 1203,
shall be of an approved type. Joints and connections shall be tight for the pressure 
of the hydronic system.
1203.1.1 Joints between different piping materials. 
Joints between different piping materials shall be 
rated for 
the temperatures and pr
essures of the systems in which the devices are installed and shall be compatible with the 
fluid and all materials provided. 
1203.
1.2 Joints between dissimilar metallic piping materials.
Joints between dissimilar metallic piping mate-
rials shall be provide
d to protect against galvanic corrosion. Such joints shall be 
made with 
dielectric fittings 
conforming to ANSI B16.39 or ASTM F 492, as applicable, shall be rated for the temperatures and pressures of 
the systems in which the devices are installed and shal
l be compatible with the fluid and all materials provided
.
Exception:
Dielectric fittings shall not be required for joints between dissimilar metal piping used within heat 
transfer appliances or equipment when such joints are provided by the appliance or e
quipment manufacturer, 
and such appliance or equipment is connected with isolation valves that are accessible.
1203.2 Preparation of pipe ends. 
Pipe shall be cut square, reamed and chamfered, and shall be free of burrs and 
obstructions. Pipe ends shall hav
e full
-
bore openings and shall not be undercut.
1203.3 Joint preparation and installation. 
Where required by Sections 1203.4 through 1203.14, the preparation and 
installation of brazed, mechanical, soldered, 
solvent
-
cemented
, threaded and welded joints shall comply with Sections 
1203.3.1 through 1203.3.8.
1203.3.1 Brazed joints.
All joints 
shall
be brazed with a 
brazing procedure developed and qualified in accordance 
with the ASME
Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications) or in accord-
ance with 
AWS 
B2.2 Standard for Brazing Procedure and Performance Qualifica
tion
.
1203.3.2 Mechanical joints. 
Mechanical joints shall be installed in accordance with the manufacturer’s instruc-
tions.
1203.3.3 Soldered joints. 
Joint surfaces shall be cleaned. A flux conforming to ASTM B 813 shall be applied. The 
joint shall be solde
red with a solder conforming to ASTM B 32.
1203.3.4 Solvent
-
cemented joints. 
Joint surfaces shall be clean and free of moisture. 
A
primer
, compatible with 
both the piping material and the cement
shall be applied to pipe
-
joint surfaces
, in accordance with t
he manufac-
turer’s requirements
. Joints shall be made while the cement is wet. Solvent cement conforming to the following 
standards shall be applied to all joint surfaces:
1.
ASTM D 2235 for ABS joints.
2.
ASTM F 493 for CPVC joints.
HYDRONIC PIPING
3.
ASTM D 2564 for PVC 
joints.
1203.3.5 Threaded joints. 
Threads shall conform to ASME B1.20.1. Schedule 80 or heavier plastic pipe shall be 
threaded with dies specifically designed for plastic pipe. Thread lubricant, pipe
-
joint compound or tape shall be 
applied on the male threads only and shall be 
compatible
f
or application on the piping material
and fluid
.
1203.3.6 Welded joints.
All joints shall be welded with a welding procedure developed and qualified in accord-
ance with the 
ASME Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications
) or in 
accordance with AWS B2.1 Specifications for Welding Procedure and Performance Qualification.
1203.3.7 Grooved and shouldered mechanical joints. 
Grooved and shouldered mechanical joints shall conform 
to the requirements of ASTM F 1476 and shall be i
nstalled in accordance with the manufacturer’s
instructions.
1203.3.8 Mechanically formed tee fittings. 
Mechanically extracted outlets shall have a height not less than three 
times the thickness of the branch tube wall.
1203.3.8.1 Full flow assurance. 
Bran
ch tubes shall not restrict the flow in the run tube. A dimple/depth stop 
shall be formed in the branch tube to ensure that penetration into the outlet is of the correct depth. For inspection 
purposes, a second dimple shall be placed
1
/
4
inch (6.4 mm) above the first dimple. Dimples shall be aligned 
with the tube run.
1203.3.8.2 Brazed joints. 
Mechanically formed tee fittings shall be brazed in accordance with Section 1203.3.1.
1203.4 ABS plastic pipe. 
Joints between ABS plastic pipe or f
ittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.5 Brass pipe. 
Joints between brass pipe or fittings shall be brazed, mechanical, threaded or welded joints con-
forming to Section 1203.3.
1203.6 Brass tubing. 
Joints bet
ween brass tubing or fittings shall be brazed, mechanical or soldered joints conforming 
to Section 1203.3.
1203.7 Copper or copper
-
alloy pipe. 
Joints between copper or copper
-
alloy pipe or fittings shall be brazed, mechan-
ical, soldered, threaded or welded 
joints conforming to Section 1203.3.
1203.8 Copper or copper
-
alloy tubing. 
Joints between copper or copper
-
alloy tubing or fittings shall be brazed, 
mechanical or soldered joints conforming to Section 1203.3, flared joints conforming to Section 1203.8.1
or
push
-
fit 
joints conforming to Section 1203.8.2.
1203.8.1 Flared joints. 
Flared joints shall be made by a tool designed for that operation.
1203.8.2 Push
-
fit joints. 
Push
-
fit joints shall be installed in accordance with the manufacturer’s instructions.
120
3.9 CPVC plastic pipe.   
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.10 Reserved.
1203.11 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints between cross
-
linked polyethyle
ne plastic tubing 
and fittings shall conform to Sections 1203.11.1 and 1203.11.2. Mechanical joints shall conform to Section 1203.3.
1203.11.1 Compression
-
type fittings. 
Where
compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings 
shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.11.2 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not less 
than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same 
water line.
1203.12 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.13 Steel pipe. 
Joints between steel pipe or fittings shall be mechanical
, threaded or welded 
joints 
conforming to 
Section 1203.3.
1203.14 Steel tubing. 
Joints between steel tubing or fittings shall be mechanical or welded joints conforming to Sec-
tion 1203.3.
HYDRONIC PIPING
1203.15 Polypropylene (PP) plastic. 
Joints between PP plastic pipe and fittings shall comp
ly with Sections 1203.15.1 
and 1203.15.2.
1203.15.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylene fittings, electro
-
fusion polypropylene fittings or by butt
fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1203.15.2 Mechanical and compression sleeve joints. 
Mechanical and compression sleeve joints shal
l be installed 
in accordance with the manufacturer’s instructions.
1203.16 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyethylene 
tubing and fittings shall conform to Sections 1203.16.1 and 1203.16.2. Mechani
cal joints shall conform to Section 
1203.3.
1203.16.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.16.2 PE
-
RT
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 mm) 
of a transition from such metal pipe to PE
-
RT pipe.
1203.17 Polyethylene/aluminum/polyethylene (PE
-
AL
-
PE) pressure pipe. 
Joints between polyethylene/alumi-
num/po
lyethylene pressure pipe and fittings shall conform to Sections 1203.17.1 and 1203.17.2. Mechanical joints 
shall comply with Section 1203.3.
1203.17.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
f
ittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.17.2 PE
-
AL
-
PE
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 
mm) of a transition from such metal pipe to PE
-
AL
-
PE pipe.
1203.18 Cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe. 
Joints 
between cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene pressure pipe and fittings shall conform to 
Sections 1203.18.1 and 1203.18.2. Mecha
nical joints shall comply with Section 1203.3.
1203.18.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.18.2 PEX
-
AL
-
PEX
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches 
(457.2 mm) of a transition from such metal pipe to PEX
-
AL
-
PEX pipe.
SECTION 
MC 
1204
PIPE INSULATION
1204.1 Insulation characteristics. 
Pipe insulation installed in buildings shall conform to the requirements of the 
New 
York City
Energy Conservation Code
,
shall be tested in accordance with ASTM E 84 or UL 723, using the specimen 
preparation and mounting p
rocedures of ASTM E 2231; and shall have a maximum flame spread index of 25 and a 
smoke
-
developed index not exceeding 450. Insulation installed in an air plenum shall comply with Section 602.2.1.
1204.2 Required thickness. 
Hydronic piping shall be insulate
d to the thickness required by the 
New York City
Energy 
Conservation Code.
SECTION 
MC 
1205
VALVES
1205.1 Where required. 
Shutoff valves shall be installed in hydronic piping systems in the locations indicated in 
Sections 1205.1.1 through 1205.1.6.
1205.1.1
Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
HYDRONIC PIPING
Exception: 
Shutoff valves shall not be required where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat 
exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1205.1.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of central utility 
systems, and district
heating and cooling 
systems.
1205.1.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1205.1.4 Pressure
-
reducing valves. 
Shutoff valves shall be installed on both sides of a pressure
-
reduc
ing valve.
1205.1.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a hydronic system such as pumps, air separators, 
metering devices and si
milar equipment.
1205.1.6 Expansion tanks.
Lockable shutoff
valves shall be installed at connections to 
all
expansion tanks.
Valves shall be locked in the open position.
1205.2 Reduced pressure. 
A pressure relief valve shall be installed on the 
low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system design. 
The valve shall be installed in accordance with Section 1006.
SECTION 
MC 
1206
PIPING INSTALLATION
1
206.1 General. 
Piping, valves, fittings and connections shall be installed in accordance with the conditions of ap-
proval.
1206.2 System drain down. 
Hydronic piping systems shall be designed and installed to permit the system to be 
drained. Where the system
drains to the plumbing drainage system, the installation shall conform to the requirements 
of the 
New York City
Plumbing Code.
Exception: 
The buried portions of systems embedded underground.
1206.3 Protection of potable water. 
The potable water system sha
ll be protected from backflow in accordance with 
the 
New York City
Plumbing Code.
1206.4 Pipe penetrations. 
Openings for pipe penetrations in walls, floors or ceilings shall be larger than the penetrat-
ing pipe. Openings through concrete or masonry building
elements shall be sleeved. The annular space surrounding 
pipe penetrations shall be protected in accordance with the 
New York City
Building Code.
1206.5 Clearance to combustibles. 
A pipe in a hydronic piping system in which the exterior temperature exceed
s 
250°F (
121.1
°C) shall have a minimum clearance of 1 inch (25.4 mm) to combustible materials.
1206.6 Contact with building material. 
A hydronic piping system shall not be in direct contact with building mate-
rials that cause the piping material to degrade 
or corrode, or that interfere with the operation of the system.
1206.7 Water hammer. 
The flow velocity of the hydronic piping system shall be controlled to reduce the possibility 
of water hammer. Where a quick
-
closing valve creates water hammer, an 
enginee
red
water
-
hammer arrestor shall be 
installed. The arrestor shall be located within a range as specified by the manufacturer of the quick
-
closing valve.
1206.8 Steam piping pitch. 
Steam piping shall be installed to drain to the boiler or the steam trap. Ste
am systems 
shall not have drip pockets that reduce the capacity of the steam piping.
1206.9 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains and stresses in the pipe. 
Provisions shall be made to protect piping from damag
e resulting from expansion, contraction and structural settle-
ment. Piping shall be installed so as to avoid structural stresses or strains within building components.
1206.9.1 Flood hazard. 
Piping located in flood hazard areas 
shall comply with Appendix G
of 
the 
New York City 
Building Code
.
HYDRONIC PIPING
1206.10 Pipe support. 
Pipe shall be supported in accordance with Section 305.
Seismic supports shall be provided 
where required by the 
New York City Building Code.
1206.11 Condensation. 
Provisions shall be made to prevent the formation of condensation on the exterior of piping.
SECTION 
MC 
1207
TRANSFER FLUID
1207.1 Flash point. 
The
flash point of transfer fluid in a hydronic piping system shall be not less than 50°F (10°C) 
above the maximum system operating temperature.
1207.2 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
SECTION 
MC 
1208
TESTS
1208.1 General. 
Hydronic piping systems 
other than ground
-
source heat pump loop systems 
shall be tested hydro-
statically at one and one
half times the system design 
operating 
pressure, but not less than 100 psi (689 kPa). The 
duration of each 
test shall be not less than
2 hours. Ground
-
source heat pump loop systems shall be tested in accord-
ance with Section 1210.10.
SECTION 
MC 
1209
EMBEDDED PIPING
1209.1 Materials. 
Embedded piping
shall be plastic pipe or tubing
, in accordance with Section 1202
,
rated at 100 psi 
(689.5 kPa) at 180°F (82.2°C).
1209.2 Pressurizing during installation. 
Piping to be embedded in concrete shall be pressure tested prior to pouring 
concrete. During pouring, the pipe shall be maintained at the proposed operating pressure
.
1209.3 Embedded joints. 
Joints of pipe or tubing that are embedded in a portion of the building, such as concrete or 
plaster, shall be thermally
-
fused.
1209.4 Not embedded related piping. 
Joints of other piping in cavities or running exposed shall be joi
ned in accord-
ance with manufacturer’s instructions and related sections of this code.
1209.5 Thermal barrier required. 
Radiant floor heating systems shall be provided with a thermal barrier in accord-
ance with Sections 1209.5.1 through 1209.5.4.
Exception: 
Insulation shall not be required in engineered systems where it can be demonstrated that the insulation 
will decrease the efficiency or have a negative effect on the installation.
1209.5.1 Slab
-
on
-
grade installation. 
Radiant piping utilized in slab
-
on
-
grad
e applications shall be provided with 
insulating materials installed beneath the piping having a minimum R
-
value of 5.
1209.5.2 Suspended floor installation. 
In suspended floor applications, insulation shall be installed in the joist 
bay cavity serving the
heating space above and shall consist of materials having a minimum R
-
value of 11.
1209.5.3 Thermal break required. 
A thermal break shall be provided consisting of asphalt expansion joint mate-
rials or similar insulating materials at a point where a heated
slab meets a foundation wall or other conductive slab.
1209.5.4 Thermal barrier material marking. 
Insulating materials utilized in thermal barriers shall be installed 
such that the manufacturer’s R
-
value mark is readily observable upon inspection.
SECTION
MC 
1210
PLASTIC PIPE GROUND
-
SOURCE HEAT PUMP LOOP SYSTEMS
HYDRONIC PIPING
1210.1 Ground
-
source heat pump
-
loop water piping. 
Ground
-
source heat pump ground
-
loop piping and tubing 
material for water
-
based systems shall conform to the standards cited in this section.
1210.2
Used materials. 
Reused pipe, fittings, valves, and other materials shall not be permitted in ground
-
source heat 
pump loop systems.
1210.3 Material rating. 
Pipe and tubing shall be rated for the operating temperature and pressure of the ground
-
source heat 
pump loop system. Fittings shall be suitable for the pressure applications and recommended by the man-
ufacturer for installation with the pipe and tubing material installed. Where used underground, materials shall be suit-
able for burial.
1210.4 Piping and t
ubing materials standards. 
Ground
-
source heat pump ground
-
loop pipe and tubing shall con-
form to the standards listed in Table 1210.4.
TABLE 1210.4
GROUND
-
SOURCE LOOP PIPE
MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl chloride 
(CPVC)
ASTM D 
2846; ASTM F 
441; ASTM F 442
Cross
-
linked polyethylene (PEX)
ASTM F 876; ASTM F 877; 
CSA B137.5
Polyethylene/aluminum/polyethylen
e (PE
-
AL
-
PE) pressure pipe
ASTM F 1282; CSA B137.9
High
-
density polyethylene (HDPE)
ASTM D 2737; ASTM D 
3035; ASTM F 
714; AWWA 
C901; CSA B137.1; CSA 
C448; NSF 358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl chloride (PVC)
ASTM D 1785; ASTM D 
2241
Raised temperature polyethylene 
(PE
-
RT)
ASTM F 2623
1210.5 Fittings. 
Ground
-
source heat pump pipe fittings shall conform to the standards listed in Table 1210.5 and, if 
installed underground, shall be suitable for burial. 
TABLE 1210.5
GROUND
-
SOURCE LOOP PIPE FITTINGS
PIPE MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl 
chloride (CPVC)
ASTM D 2846; ASTM F 437; ASTM F 
438; ASTM F 439; CSA B137.6
Cross
-
linked 
polyethylene (PEX)
ASTM F 877; ASTM F 1807; ASTM F 
1960; ASTM F 2080; ASTM F 2159; 
ASTM F 2434; CSA B137.5
Polyethylene/aluminum/
polyethylene (PE
-
AL
-
PE)
ASTM F 1282; ASTM F 2434; CSA 
B137.9
HYDRONIC PIPING
High Density 
Polyethylene (HDPE)
ASTM D 2683; ASTM D 3261; ASTM 
F 1055; CSA B137.1; CSA C448; NSF 
358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl 
chloride 
(PVC)
ASTM D 2464; ASTM D 2466; ASTM 
D 2467; CSA B137.2; CSA B137.3
Raised temperature 
polyethylene (PE
-
RT)
ASTM D 3261; ASTM F 1807; ASTM 
F 2159; CSA B137.1
1210.6 Joints. 
Joints and connections, 
other than those covered by Section 1210 and co
nforming to the ASTM stand-
ards listed therein,
shall be of an approved type. Joints and connections shall be tight for the pressure of the ground
-
source loop system. Joints used underground shall be in accordance with manufacturer’s instructions for buried
appli-
cations.
1210.6.1 Joints between different piping materials. 
Joints between different piping materials shall be made with 
transition fittings compatible with both materials and the fluid contained within the system. Transition fittings must 
be used i
n accordance with manufacturer’s instructions.
1210.6.1.1 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not 
less than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same water line.
1210.6.2 Prep
aration of pipe ends. 
Pipe shall be cut square, be reamed, and be free of burrs and obstructions. 
CPVC, PE, and PVC pipe shall be chamfered. Pipe ends shall have full
-
bore openings and shall not be undercut.
1210.6.3 Joint preparation and installation. 
Whe
re required by Sections 1210.6.4 through 1210.6.6, the prepa-
ration and installation of mechanical and thermoplastic
-
welded joints shall comply with Sections 1210.6.3.1 and 
1210.6.3.2.
1210.6.3.1 Mechanical joints. 
Mechanical joints shall be installed in ac
cordance with the manufacturer’s in-
structions.
1210.6.3.2 Thermoplastic
-
welded joints. 
Joint surfaces for thermoplastic
-
welded joints shall be cleaned by a 
procedure in accordance with the manufacturer’s instructions. Joints shall be welded in accordance w
ith the 
manufacturer’s instructions.
1210.6.4 CPVC plastic pipe. 
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded 
joints complying with Section 1203.3.
‡‡‡
1210.6.5 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints bet
ween cross
-
linked polyethylene plastic 
tubing and fittings shall comply with Section 1210.6.5.1. Mechanical joints shall comply with Section 1210.6.3.
1210.6.5.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
r
ings, 
the fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1210.6.6 Polyethylene plastic pipe and tubing for ground
-
source heat pump loop systems. 
Joints between 
polyethylene plastic pipe and tubing or fittings for 
ground
-
source heat pump loop systems shall be heat fusion 
joints complying with Section 1210.6.6.1, electrofusion joints complying with Section 1210.6.6.2, or stab
-
type 
insertion joints complying with Section 1210.6.6.3.
1210.6.6.1 Heat
-
fusion joints. 
Joints shall be of the socket
-
fusion, saddle
-
fusion or butt
-
fusion type, joined in 
accordance with ASTM D 2657. Joint surfaces shall be clean and free from moisture. Joint surfaces shall be 
heated to melt temperatures and joi
ned. The joint shall be undisturbed until cool. Fittings shall be manufactured 
in accordance with ASTM D 2683 or ASTM D 3261.
1210.6.6.2 Electrofusion joints. 
Joints shall be of the electrofusion type. Joint surfaces shall be clean and free 
from moisture, 
and scoured to expose virgin resin. Joint surfaces shall be heated to melt temperatures for the 
‡‡‡ Chapter 12 was amended by 
Local Law 
77 
of 2023
. This law has an effective
date of June 10, 2023.
CHAPTER 12
HYDRONIC PIPING 
SECTION MC 1201
GENERAL
1201.1 Scope. 
The provisions of this chapter shall govern the construction, installation, alteration and repair of hy-
dronic piping systems. This chapter shall apply to hydronic piping systems that are part of heating, ventilation and air
-
conditioning systems. Such piping systems shall include steam, hot water, chilled water, condenser water, cooling 
coil condensate drain, 
steam condensate and ground
-
source heat pump loop systems. Potable cold and hot water dis-
tribution systems shall be installed in accordance with the 
New York City
Plumbing Code
. 
1201.2 Sizing. 
Piping and piping system components for hydronic systems shall be sized for the 
design requirements
of the system.
1201.3 Standards. 
As an alternative to the provisions of Sections 1202 and 1203, piping shall be designed, installed, 
inspected and tested in accordance with ASME B31.
1 and ASME B31.9, as applicable
. 
SECTION 
MC 
1202
MATERIAL
1202.1 Piping. 
Piping material, other than those contained within this section and conforming with the ASTM stand-
ards listed within this chapter, shall be of an approved type.
Exception: 
Embedded piping regulated by Section 1209, and ground
-
source heat pump loop systems regulated by 
Section 1210.
1202.2 Used existing materials. 
Reused pipe, fittings, valves or other materials shall be clean and free of foreign 
materials.
1202.3 Material rating. 
Materials shall be rated for the operating temperature and pressure of the hydronic system. 
Materials shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards. 
Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior 
of the pipe shall be protected from corrosion and d
egradation.
TABLE 1202.4
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene 
(ABS) plastic pipe
ASTM D 1527; ASTM F 2806
Chlorinated polyvinyl chloride 
(CPVC) plastic pipe
ASTM D 2846; ASTM F 441; 
ASTM F 442
Copper, 
brass, or copper
-
alloy 
pipe
ASTM B 42; ASTM B 43; 
ASTM B 302
Copper, brass, or copper
-
alloy 
tube (Type K, L or M)
ASTM B 75; ASTM B 88; 
ASTM B 135; ASTM B 251
HYDRONIC PIPING
Cross
-
linked 
polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe
ASTM F 1281; CSA
B137.10
Cross
-
linked polyethylene 
(PEX) tubing
ASTM F 876; ASTM F 877
Ductile iron pipe
AWWA C115/A21.15; AWWA 
C151/A21.51 
Polyethylene/aluminum/
polyet
hylene 
(PE
-
AL
-
PE) pressure 
pipe
ASTM F 1282; CSA B137.9
Polypropylene (PP) 
plastic pipe
ASTM F 2389
Polyvinyl chloride (PVC) 
plastic pipe
ASTM D 1785; ASTM D 2241
Raised temperature 
polyethylene (PE
-
RT)
ASTM F 2623; ASTM F 2769
Steel pipe
ASTM A 53/A 53M; ASTM A 
106
Steel tubing
ASTM A 254
1202.5 Pipe fittings. 
Hydronic pipe fittings shall conform to the respective pipe standards or to the standards listed in 
Table 1202.5.
TABLE 1202.5
HYDRONIC PIPE FITTINGS
MATERIAL
STANDARD (see Chapter 15)
Copper, brass, and copper 
alloys
ASME B16.15; ASME B16.18; ASME 
B16.22; 
ASME B16.24; 
ASME 
B16.26; 
ASME B16.51; ASTM F 
1974 
Ductile iron and gray iron
ANSI/AWWA C110/A21.10; 
AWWA C153/A21.53; ASTM A 
126; ASTM A 395; ASTM A 536; 
ASTM F 1476; ASTM F 1548
Malleable iron
ASME B16.3
PE
-
RT fittings
ASTM F 1807; ASTM F 2098; 
ASTM F 2159; ASTM F 2735; 
ASTM F 2769
PEX fittings
ASTM F 877; ASTM F 1807; ASTM 
F 2159
Plastic
ASTM D 2466; ASTM D 2467; 
ASTM F 438; ASTM F 439; ASTM 
F
877; ASTM F 2389; ASTM F 2735
HYDRONIC PIPING
Steel
ASME B16.5; ASME 
B16.9; ASME 
B16.11; ASME B16.28; ASTM A 
53/A 53M; ASTM A 106; ASTM A 
234; ASTM A 420; ASTM A 536; 
ASTM A 395; ASTM F 1476; ASTM 
F 1548
1202.6 Valves. 
Valves shall be constructed of materials that are compatible with the type of piping material and fluids 
in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration compensators. 
Flexible connectors, expansion and vibration 
control devices and fit
tings
, when used, shall protect the components of the hydronic system from damage caused by 
expansion, contraction, transverse movement, angular deflection and vibration,
shall be 
rated for the temperatures 
and pressures of the systems in which the devices
are installed, and shall be compatible with the fluid and all materials 
provided
.
SECTION 
MC 
1203
JOINTS AND CONNECTIONS
1203.1 Approval. 
Joints and connections
, other than those contained in Section 1203 and conforming to the ASTM 
standards listed in Sec
tion 1203,
shall be of an approved type. Joints and connections shall be tight for the pressure 
of the hydronic system.
1203.1.1 Joints between different piping materials. 
Joints between different piping materials shall be 
rated for 
the temperatures and pr
essures of the systems in which the devices are installed and shall be compatible with the 
fluid and all materials provided. 
1203.
1.2 Joints between dissimilar metallic piping materials.
Joints between dissimilar metallic piping mate-
rials shall be provide
d to protect against galvanic corrosion. Such joints shall be 
made with 
dielectric fittings 
conforming to ANSI B16.39 or ASTM F 492, as applicable, shall be rated for the temperatures and pressures of 
the systems in which the devices are installed and shal
l be compatible with the fluid and all materials provided
.
Exception:
Dielectric fittings shall not be required for joints between dissimilar metal piping used within heat 
transfer appliances or equipment when such joints are provided by the appliance or e
quipment manufacturer, 
and such appliance or equipment is connected with isolation valves that are accessible.
1203.2 Preparation of pipe ends. 
Pipe shall be cut square, reamed and chamfered, and shall be free of burrs and 
obstructions. Pipe ends shall hav
e full
-
bore openings and shall not be undercut.
1203.3 Joint preparation and installation. 
Where required by Sections 1203.4 through 1203.14, the preparation and 
installation of brazed, mechanical, soldered, 
solvent
-
cemented
, threaded and welded joints shall comply with Sections 
1203.3.1 through 1203.3.8.
1203.3.1 Brazed joints.
All joints 
shall
be brazed with a 
brazing procedure developed and qualified in accordance 
with the ASME
Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications) or in accord-
ance with 
AWS 
B2.2 Standard for Brazing Procedure and Performance Qualifica
tion
.
1203.3.2 Mechanical joints. 
Mechanical joints shall be installed in accordance with the manufacturer’s instruc-
tions.
1203.3.3 Soldered joints. 
Joint surfaces shall be cleaned. A flux conforming to ASTM B 813 shall be applied. The 
joint shall be solde
red with a solder conforming to ASTM B 32.
1203.3.4 Solvent
-
cemented joints. 
Joint surfaces shall be clean and free of moisture. 
A
primer
, compatible with 
both the piping material and the cement
shall be applied to pipe
-
joint surfaces
, in accordance with t
he manufac-
turer’s requirements
. Joints shall be made while the cement is wet. Solvent cement conforming to the following 
standards shall be applied to all joint surfaces:
1.
ASTM D 2235 for ABS joints.
2.
ASTM F 493 for CPVC joints.
HYDRONIC PIPING
3.
ASTM D 2564 for PVC 
joints.
1203.3.5 Threaded joints. 
Threads shall conform to ASME B1.20.1. Schedule 80 or heavier plastic pipe shall be 
threaded with dies specifically designed for plastic pipe. Thread lubricant, pipe
-
joint compound or tape shall be 
applied on the male threads only and shall be 
compatible
f
or application on the piping material
and fluid
.
1203.3.6 Welded joints.
All joints shall be welded with a welding procedure developed and qualified in accord-
ance with the 
ASME Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications
) or in 
accordance with AWS B2.1 Specifications for Welding Procedure and Performance Qualification.
1203.3.7 Grooved and shouldered mechanical joints. 
Grooved and shouldered mechanical joints shall conform 
to the requirements of ASTM F 1476 and shall be i
nstalled in accordance with the manufacturer’s
instructions.
1203.3.8 Mechanically formed tee fittings. 
Mechanically extracted outlets shall have a height not less than three 
times the thickness of the branch tube wall.
1203.3.8.1 Full flow assurance. 
Bran
ch tubes shall not restrict the flow in the run tube. A dimple/depth stop 
shall be formed in the branch tube to ensure that penetration into the outlet is of the correct depth. For inspection 
purposes, a second dimple shall be placed
1
/
4
inch (6.4 mm) above the first dimple. Dimples shall be aligned 
with the tube run.
1203.3.8.2 Brazed joints. 
Mechanically formed tee fittings shall be brazed in accordance with Section 1203.3.1.
1203.4 ABS plastic pipe. 
Joints between ABS plastic pipe or f
ittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.5 Brass pipe. 
Joints between brass pipe or fittings shall be brazed, mechanical, threaded or welded joints con-
forming to Section 1203.3.
1203.6 Brass tubing. 
Joints bet
ween brass tubing or fittings shall be brazed, mechanical or soldered joints conforming 
to Section 1203.3.
1203.7 Copper or copper
-
alloy pipe. 
Joints between copper or copper
-
alloy pipe or fittings shall be brazed, mechan-
ical, soldered, threaded or welded 
joints conforming to Section 1203.3.
1203.8 Copper or copper
-
alloy tubing. 
Joints between copper or copper
-
alloy tubing or fittings shall be brazed, 
mechanical or soldered joints conforming to Section 1203.3, flared joints conforming to Section 1203.8.1
or
push
-
fit 
joints conforming to Section 1203.8.2.
1203.8.1 Flared joints. 
Flared joints shall be made by a tool designed for that operation.
1203.8.2 Push
-
fit joints. 
Push
-
fit joints shall be installed in accordance with the manufacturer’s instructions.
120
3.9 CPVC plastic pipe.   
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.10 Reserved.
1203.11 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints between cross
-
linked polyethyle
ne plastic tubing 
and fittings shall conform to Sections 1203.11.1 and 1203.11.2. Mechanical joints shall conform to Section 1203.3.
1203.11.1 Compression
-
type fittings. 
Where
compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings 
shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.11.2 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not less 
than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same 
water line.
1203.12 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.13 Steel pipe. 
Joints between steel pipe or fittings shall be mechanical
, threaded or welded 
joints 
conforming to 
Section 1203.3.
1203.14 Steel tubing. 
Joints between steel tubing or fittings shall be mechanical or welded joints conforming to Sec-
tion 1203.3.
HYDRONIC PIPING
1203.15 Polypropylene (PP) plastic. 
Joints between PP plastic pipe and fittings shall comp
ly with Sections 1203.15.1 
and 1203.15.2.
1203.15.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylene fittings, electro
-
fusion polypropylene fittings or by butt
fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1203.15.2 Mechanical and compression sleeve joints. 
Mechanical and compression sleeve joints shal
l be installed 
in accordance with the manufacturer’s instructions.
1203.16 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyethylene 
tubing and fittings shall conform to Sections 1203.16.1 and 1203.16.2. Mechani
cal joints shall conform to Section 
1203.3.
1203.16.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.16.2 PE
-
RT
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 mm) 
of a transition from such metal pipe to PE
-
RT pipe.
1203.17 Polyethylene/aluminum/polyethylene (PE
-
AL
-
PE) pressure pipe. 
Joints between polyethylene/alumi-
num/po
lyethylene pressure pipe and fittings shall conform to Sections 1203.17.1 and 1203.17.2. Mechanical joints 
shall comply with Section 1203.3.
1203.17.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
f
ittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.17.2 PE
-
AL
-
PE
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 
mm) of a transition from such metal pipe to PE
-
AL
-
PE pipe.
1203.18 Cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe. 
Joints 
between cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene pressure pipe and fittings shall conform to 
Sections 1203.18.1 and 1203.18.2. Mecha
nical joints shall comply with Section 1203.3.
1203.18.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.18.2 PEX
-
AL
-
PEX
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches 
(457.2 mm) of a transition from such metal pipe to PEX
-
AL
-
PEX pipe.
SECTION 
MC 
1204
PIPE INSULATION
1204.1 Insulation characteristics. 
Pipe insulation installed in buildings shall conform to the requirements of the 
New 
York City
Energy Conservation Code
,
shall be tested in accordance with ASTM E 84 or UL 723, using the specimen 
preparation and mounting p
rocedures of ASTM E 2231; and shall have a maximum flame spread index of 25 and a 
smoke
-
developed index not exceeding 450. Insulation installed in an air plenum shall comply with Section 602.2.1.
1204.2 Required thickness. 
Hydronic piping shall be insulate
d to the thickness required by the 
New York City
Energy 
Conservation Code.
SECTION 
MC 
1205
VALVES
1205.1 Where required. 
Shutoff valves shall be installed in hydronic piping systems in the locations indicated in 
Sections 1205.1.1 through 1205.1.6.
1205.1.1
Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
HYDRONIC PIPING
Exception: 
Shutoff valves shall not be required where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat 
exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1205.1.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of central utility 
systems, and district
heating and cooling 
systems.
1205.1.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1205.1.4 Pressure
-
reducing valves. 
Shutoff valves shall be installed on both sides of a pressure
-
reduc
ing valve.
1205.1.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a hydronic system such as pumps, air separators, 
metering devices and si
milar equipment.
1205.1.6 Expansion tanks.
Lockable shutoff
valves shall be installed at connections to 
all
expansion tanks.
Valves shall be locked in the open position.
1205.2 Reduced pressure. 
A pressure relief valve shall be installed on the 
low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system design. 
The valve shall be installed in accordance with Section 1006.
SECTION 
MC 
1206
PIPING INSTALLATION
1
206.1 General. 
Piping, valves, fittings and connections shall be installed in accordance with the conditions of ap-
proval.
1206.2 System drain down. 
Hydronic piping systems shall be designed and installed to permit the system to be 
drained. Where the system
drains to the plumbing drainage system, the installation shall conform to the requirements 
of the 
New York City
Plumbing Code.
Exception: 
The buried portions of systems embedded underground.
1206.3 Protection of potable water. 
The potable water system sha
ll be protected from backflow in accordance with 
the 
New York City
Plumbing Code.
1206.4 Pipe penetrations. 
Openings for pipe penetrations in walls, floors or ceilings shall be larger than the penetrat-
ing pipe. Openings through concrete or masonry building
elements shall be sleeved. The annular space surrounding 
pipe penetrations shall be protected in accordance with the 
New York City
Building Code.
1206.5 Clearance to combustibles. 
A pipe in a hydronic piping system in which the exterior temperature exceed
s 
250°F (
121.1
°C) shall have a minimum clearance of 1 inch (25.4 mm) to combustible materials.
1206.6 Contact with building material. 
A hydronic piping system shall not be in direct contact with building mate-
rials that cause the piping material to degrade 
or corrode, or that interfere with the operation of the system.
1206.7 Water hammer. 
The flow velocity of the hydronic piping system shall be controlled to reduce the possibility 
of water hammer. Where a quick
-
closing valve creates water hammer, an 
enginee
red
water
-
hammer arrestor shall be 
installed. The arrestor shall be located within a range as specified by the manufacturer of the quick
-
closing valve.
1206.8 Steam piping pitch. 
Steam piping shall be installed to drain to the boiler or the steam trap. Ste
am systems 
shall not have drip pockets that reduce the capacity of the steam piping.
1206.9 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains and stresses in the pipe. 
Provisions shall be made to protect piping from damag
e resulting from expansion, contraction and structural settle-
ment. Piping shall be installed so as to avoid structural stresses or strains within building components.
1206.9.1 Flood hazard. 
Piping located in flood hazard areas 
shall comply with Appendix G
of 
the 
New York City 
Building Code
.
HYDRONIC PIPING
1206.10 Pipe support. 
Pipe shall be supported in accordance with Section 305.
Seismic supports shall be provided 
where required by the 
New York City Building Code.
1206.11 Condensation. 
Provisions shall be made to prevent the formation of condensation on the exterior of piping.
SECTION 
MC 
1207
TRANSFER FLUID
1207.1 Flash point. 
The
flash point of transfer fluid in a hydronic piping system shall be not less than 50°F (10°C) 
above the maximum system operating temperature.
1207.2 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
SECTION 
MC 
1208
TESTS
1208.1 General. 
Hydronic piping systems 
other than ground
-
source heat pump loop systems 
shall be tested hydro-
statically at one and one
half times the system design 
operating 
pressure, but not less than 100 psi (689 kPa). The 
duration of each 
test shall be not less than
2 hours. Ground
-
source heat pump loop systems shall be tested in accord-
ance with Section 1210.10.
SECTION 
MC 
1209
EMBEDDED PIPING
1209.1 Materials. 
Embedded piping
shall be plastic pipe or tubing
, in accordance with Section 1202
,
rated at 100 psi 
(689.5 kPa) at 180°F (82.2°C).
1209.2 Pressurizing during installation. 
Piping to be embedded in concrete shall be pressure tested prior to pouring 
concrete. During pouring, the pipe shall be maintained at the proposed operating pressure
.
1209.3 Embedded joints. 
Joints of pipe or tubing that are embedded in a portion of the building, such as concrete or 
plaster, shall be thermally
-
fused.
1209.4 Not embedded related piping. 
Joints of other piping in cavities or running exposed shall be joi
ned in accord-
ance with manufacturer’s instructions and related sections of this code.
1209.5 Thermal barrier required. 
Radiant floor heating systems shall be provided with a thermal barrier in accord-
ance with Sections 1209.5.1 through 1209.5.4.
Exception: 
Insulation shall not be required in engineered systems where it can be demonstrated that the insulation 
will decrease the efficiency or have a negative effect on the installation.
1209.5.1 Slab
-
on
-
grade installation. 
Radiant piping utilized in slab
-
on
-
grad
e applications shall be provided with 
insulating materials installed beneath the piping having a minimum R
-
value of 5.
1209.5.2 Suspended floor installation. 
In suspended floor applications, insulation shall be installed in the joist 
bay cavity serving the
heating space above and shall consist of materials having a minimum R
-
value of 11.
1209.5.3 Thermal break required. 
A thermal break shall be provided consisting of asphalt expansion joint mate-
rials or similar insulating materials at a point where a heated
slab meets a foundation wall or other conductive slab.
1209.5.4 Thermal barrier material marking. 
Insulating materials utilized in thermal barriers shall be installed 
such that the manufacturer’s R
-
value mark is readily observable upon inspection.
SECTION
MC 
1210
PLASTIC PIPE GROUND
-
SOURCE HEAT PUMP LOOP SYSTEMS
HYDRONIC PIPING
1210.1 Ground
-
source heat pump
-
loop water piping. 
Ground
-
source heat pump ground
-
loop piping and tubing 
material for water
-
based systems shall conform to the standards cited in this section.
1210.2
Used materials. 
Reused pipe, fittings, valves, and other materials shall not be permitted in ground
-
source heat 
pump loop systems.
1210.3 Material rating. 
Pipe and tubing shall be rated for the operating temperature and pressure of the ground
-
source heat 
pump loop system. Fittings shall be suitable for the pressure applications and recommended by the man-
ufacturer for installation with the pipe and tubing material installed. Where used underground, materials shall be suit-
able for burial.
1210.4 Piping and t
ubing materials standards. 
Ground
-
source heat pump ground
-
loop pipe and tubing shall con-
form to the standards listed in Table 1210.4.
TABLE 1210.4
GROUND
-
SOURCE LOOP PIPE
MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl chloride 
(CPVC)
ASTM D 
2846; ASTM F 
441; ASTM F 442
Cross
-
linked polyethylene (PEX)
ASTM F 876; ASTM F 877; 
CSA B137.5
Polyethylene/aluminum/polyethylen
e (PE
-
AL
-
PE) pressure pipe
ASTM F 1282; CSA B137.9
High
-
density polyethylene (HDPE)
ASTM D 2737; ASTM D 
3035; ASTM F 
714; AWWA 
C901; CSA B137.1; CSA 
C448; NSF 358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl chloride (PVC)
ASTM D 1785; ASTM D 
2241
Raised temperature polyethylene 
(PE
-
RT)
ASTM F 2623
1210.5 Fittings. 
Ground
-
source heat pump pipe fittings shall conform to the standards listed in Table 1210.5 and, if 
installed underground, shall be suitable for burial. 
TABLE 1210.5
GROUND
-
SOURCE LOOP PIPE FITTINGS
PIPE MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl 
chloride (CPVC)
ASTM D 2846; ASTM F 437; ASTM F 
438; ASTM F 439; CSA B137.6
Cross
-
linked 
polyethylene (PEX)
ASTM F 877; ASTM F 1807; ASTM F 
1960; ASTM F 2080; ASTM F 2159; 
ASTM F 2434; CSA B137.5
Polyethylene/aluminum/
polyethylene (PE
-
AL
-
PE)
ASTM F 1282; ASTM F 2434; CSA 
B137.9
HYDRONIC PIPING
High Density 
Polyethylene (HDPE)
ASTM D 2683; ASTM D 3261; ASTM 
F 1055; CSA B137.1; CSA C448; NSF 
358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl 
chloride 
(PVC)
ASTM D 2464; ASTM D 2466; ASTM 
D 2467; CSA B137.2; CSA B137.3
Raised temperature 
polyethylene (PE
-
RT)
ASTM D 3261; ASTM F 1807; ASTM 
F 2159; CSA B137.1
1210.6 Joints. 
Joints and connections, 
other than those covered by Section 1210 and co
nforming to the ASTM stand-
ards listed therein,
shall be of an approved type. Joints and connections shall be tight for the pressure of the ground
-
source loop system. Joints used underground shall be in accordance with manufacturer’s instructions for buried
appli-
cations.
1210.6.1 Joints between different piping materials. 
Joints between different piping materials shall be made with 
transition fittings compatible with both materials and the fluid contained within the system. Transition fittings must 
be used i
n accordance with manufacturer’s instructions.
1210.6.1.1 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not 
less than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same water line.
1210.6.2 Prep
aration of pipe ends. 
Pipe shall be cut square, be reamed, and be free of burrs and obstructions. 
CPVC, PE, and PVC pipe shall be chamfered. Pipe ends shall have full
-
bore openings and shall not be undercut.
1210.6.3 Joint preparation and installation. 
Whe
re required by Sections 1210.6.4 through 1210.6.6, the prepa-
ration and installation of mechanical and thermoplastic
-
welded joints shall comply with Sections 1210.6.3.1 and 
1210.6.3.2.
1210.6.3.1 Mechanical joints. 
Mechanical joints shall be installed in ac
cordance with the manufacturer’s in-
structions.
1210.6.3.2 Thermoplastic
-
welded joints. 
Joint surfaces for thermoplastic
-
welded joints shall be cleaned by a 
procedure in accordance with the manufacturer’s instructions. Joints shall be welded in accordance w
ith the 
manufacturer’s instructions.
1210.6.4 CPVC plastic pipe. 
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded 
joints complying with Section 1203.3.
‡‡‡
1210.6.5 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints bet
ween cross
-
linked polyethylene plastic 
tubing and fittings shall comply with Section 1210.6.5.1. Mechanical joints shall comply with Section 1210.6.3.
1210.6.5.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
r
ings, 
the fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1210.6.6 Polyethylene plastic pipe and tubing for ground
-
source heat pump loop systems. 
Joints between 
polyethylene plastic pipe and tubing or fittings for 
ground
-
source heat pump loop systems shall be heat fusion 
joints complying with Section 1210.6.6.1, electrofusion joints complying with Section 1210.6.6.2, or stab
-
type 
insertion joints complying with Section 1210.6.6.3.
1210.6.6.1 Heat
-
fusion joints. 
Joints shall be of the socket
-
fusion, saddle
-
fusion or butt
-
fusion type, joined in 
accordance with ASTM D 2657. Joint surfaces shall be clean and free from moisture. Joint surfaces shall be 
heated to melt temperatures and joi
ned. The joint shall be undisturbed until cool. Fittings shall be manufactured 
in accordance with ASTM D 2683 or ASTM D 3261.
1210.6.6.2 Electrofusion joints. 
Joints shall be of the electrofusion type. Joint surfaces shall be clean and free 
from moisture, 
and scoured to expose virgin resin. Joint surfaces shall be heated to melt temperatures for the 
HYDRONIC PIPING
period of time specified by the manufacturer. The joint shall be undisturbed until cool. Fittings shall be manu-
factured in accordance with ASTM F 1055.
1210.6.6
.3 Stab
-
type insert fittings. 
Joint surfaces shall be clean and free from moisture. Pipe ends shall be 
chamfered and inserted into the fittings to full depth. Fittings shall be manufactured in accordance with ASTM 
F 1924.
1210.6.7 Polypropylene (PP) plasti
c. 
Joints between PP plastic pipe and fittings shall comply with Sections 
1210.6.7.1 and 1210.6.7.2.
1210.6.7.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylen
e fittings, electrofusion polypropylene fittings or by butt fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1210.6.7.2 Mechanical and compression 
sleeve joints. 
Mechanical and compression sleeve joints shall be 
installed in accordance with the manufacturer’s instructions.
1210.6.8 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyeth-
ylene tubing and fittin
gs shall comply with Sections 1210.6.8.1 and 1210.6.8.2. Mechanical joints shall comply 
with Section 1210.6.3.
1210.6.8.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, 
the fittings shall be installed wi
thout omitting the inserts and ferrules or O
-
rings.
1210.6.9 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded 
joints comply with Section 1203.3.
1210.7 Shutoff valves. 
Shutoff valves shall be installed in
ground
-
source loop piping systems in the locations indi-
cated in Sections 1210.7.1 through 1210.7.7.
1210.7.1 Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
Exception: 
Shutoff valves shall not be requi
red where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1210
.7.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of a central utility 
system.
1210.7.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1210.7.4 Pressure
-
reducing valves.
Shutoff valves shall be installed on both sides of a pressure
-
reducing valve.
1210.7.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a gr
ound
-
source loop system such as pumps, air 
separators, metering devices, and similar equipment.
1210.7.6 Expansion tanks. 
Shutoff valves shall be installed at connections to nondiaphragm
-
type expansion tanks.
1210.7.7 Reduced pressure. 
A pressure relief va
lve shall be installed on the low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system 
design. The valve shall be installed in accordance with Section 1006.
1210.8 
Installation. 
Piping, valves, fittings, and connections shall be installed in accordance with the 
conditions of approval.
1210.8.1 Protection of potable water. 
Where ground
-
source heat pump ground
-
loop systems have a connection 
to a potable water supply, t
he potable water system shall be protected from backflow in accordance with the 
New 
York City Plumbing Code
.
1210.8.2 Pipe penetrations. 
Openings for pipe penetrations in walls, floors and ceilings shall be larger than the 
penetrating pipe. Openings throug
h concrete or masonry building elements shall be sleeved. The annular space 
surrounding pipe penetrations shall be protected in accordance with the 
New York City Building Code
.
HYDRONIC PIPING
1210.8.3 Clearance from combustibles. 
A pipe in a ground
-
source heat pump pipin
g system having an exterior 
surface temperature exceeding 250°F (121.1°C) shall have a minimum clearance of 1 inch (25.4 mm) from com-
bustible materials.
1210.8.4 Contact with building material. 
A ground
-
source heat pump ground
-
loop piping system shall not 
be in 
direct contact with building materials that cause the piping or fitting material to degrade or corrode, or that interfere 
with the operation of the system.
1210.8.5 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains 
and stresses in the pipe. 
Provisions shall be made to protect piping from damage resulting from expansion, contraction and structural set-
tlement. Piping shall be installed so as to avoid structural stresses or strains within building components.
1210.8.6 F
lood hazard. 
Piping located in a flood hazard area shall be capable of resisting hydrostatic and hydro-
dynamic loads and stresses, including the effects of buoyancy, during the occurrence of flooding to the design flood 
elevation.
1210.8.7 Pipe support. 
Pip
e shall be supported in accordance with Section 305.
1210.8.8 Velocities. 
Ground
-
source heat pump ground
-
loop systems shall be designed so that the flow velocities 
do not exceed the maximum flow velocity recommended by the pipe and fittings 
manufacturer and shall be con-
trolled to reduce the possibility of water hammer.
1210.8.9 Labeling and marking. 
Ground
-
source heat pump ground
-
loop system piping shall be marked with tape, 
metal tags or other method where it enters a building indicating “GR
OUND
-
SOURCE HEAT PUMP LOOP SYS-
TEM.” The marking shall indicate any antifreeze used in the system by name and concentration.
1210.8.10 Chemical compatibility. 
Antifreeze and other materials used in the system shall be chemically compat-
ible with the 
pipe, tubing, fittings, and mechanical systems.
1210.9 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
1210.10 Tests. 
Before connection header trenches are backfilled, the assembled loop system shall be pr
essure tested 
with water at 100 psi (689.5 kPa) for 15 minutes, in which time there shall not be observed leaks. Flow and pressure 
loss testing shall be performed and the actual flow rates and pressure drops shall be compared to the calculated design 
value
s. If actual flow rate or pressure drop values differ from calculated design values by more than 10 percent, the 
cause shall be identified and corrective action taken.
1210.11 Embedded piping. 
Ground
-
source heat pump ground
-
loop piping to be embedded in co
ncrete shall be pres-
sure tested prior to pouring concrete. During pouring, the pipe shall be maintained at the proposed operating pressure. 
Embedded piping shall comply with Section 1209.
SECTION MC 1211
HIGH
-
PRESSURE STEAM AND
HIGH TEMPERATURE HOT WATER P
IPING SYSTEMS
1211.1 Scope.
The provisions of this section shall apply to high
-
pressure steam piping system, which is defined as a 
system operating at a steam pressure of more than 15 psi (103.4 kPa), and high temperature water intended for 
operation at pr
essures in excess of 160 psi (1103.2 kPa) and temperatures in excess of 250°F (121.1°C). For purposes 
of this section, loops, bends or offsets of the piping shall not be considered expansion joints.
1211.2 New systems.
For purposes of this section, the rep
lacement of existing steam piping systems, the installation 
of a new system in existing buildings, as well as installations in buildings hereafter constructed, shall be considered 
to be new high
-
pressure steam piping systems. The following requirements are
applicable:
1211.2.1 Design.
The design of new steam piping systems shall be conducted as follows:
1.
The system shall be designed by an engineer. An application and plans shall be filed and the approval of the 
department obtained. The plans and applicati
on shall contain, but not be limited to, the following information:
1.1.
Size and location of all steam piping.
‡‡‡ Chapter 12 was amended by 
Local Law 
77 
of 2023
. This law has an effective
date of June 10, 2023.
CHAPTER 12
HYDRONIC PIPING 
SECTION MC 1201
GENERAL
1201.1 Scope. 
The provisions of this chapter shall govern the construction, installation, alteration and repair of hy-
dronic piping systems. This chapter shall apply to hydronic piping systems that are part of heating, ventilation and air
-
conditioning systems. Such piping systems shall include steam, hot water, chilled water, condenser water, cooling 
coil condensate drain, 
steam condensate and ground
-
source heat pump loop systems. Potable cold and hot water dis-
tribution systems shall be installed in accordance with the 
New York City
Plumbing Code
. 
1201.2 Sizing. 
Piping and piping system components for hydronic systems shall be sized for the 
design requirements
of the system.
1201.3 Standards. 
As an alternative to the provisions of Sections 1202 and 1203, piping shall be designed, installed, 
inspected and tested in accordance with ASME B31.
1 and ASME B31.9, as applicable
. 
SECTION 
MC 
1202
MATERIAL
1202.1 Piping. 
Piping material, other than those contained within this section and conforming with the ASTM stand-
ards listed within this chapter, shall be of an approved type.
Exception: 
Embedded piping regulated by Section 1209, and ground
-
source heat pump loop systems regulated by 
Section 1210.
1202.2 Used existing materials. 
Reused pipe, fittings, valves or other materials shall be clean and free of foreign 
materials.
1202.3 Material rating. 
Materials shall be rated for the operating temperature and pressure of the hydronic system. 
Materials shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards. 
Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior 
of the pipe shall be protected from corrosion and d
egradation.
TABLE 1202.4
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene 
(ABS) plastic pipe
ASTM D 1527; ASTM F 2806
Chlorinated polyvinyl chloride 
(CPVC) plastic pipe
ASTM D 2846; ASTM F 441; 
ASTM F 442
Copper, 
brass, or copper
-
alloy 
pipe
ASTM B 42; ASTM B 43; 
ASTM B 302
Copper, brass, or copper
-
alloy 
tube (Type K, L or M)
ASTM B 75; ASTM B 88; 
ASTM B 135; ASTM B 251
HYDRONIC PIPING
Cross
-
linked 
polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe
ASTM F 1281; CSA
B137.10
Cross
-
linked polyethylene 
(PEX) tubing
ASTM F 876; ASTM F 877
Ductile iron pipe
AWWA C115/A21.15; AWWA 
C151/A21.51 
Polyethylene/aluminum/
polyet
hylene 
(PE
-
AL
-
PE) pressure 
pipe
ASTM F 1282; CSA B137.9
Polypropylene (PP) 
plastic pipe
ASTM F 2389
Polyvinyl chloride (PVC) 
plastic pipe
ASTM D 1785; ASTM D 2241
Raised temperature 
polyethylene (PE
-
RT)
ASTM F 2623; ASTM F 2769
Steel pipe
ASTM A 53/A 53M; ASTM A 
106
Steel tubing
ASTM A 254
1202.5 Pipe fittings. 
Hydronic pipe fittings shall conform to the respective pipe standards or to the standards listed in 
Table 1202.5.
TABLE 1202.5
HYDRONIC PIPE FITTINGS
MATERIAL
STANDARD (see Chapter 15)
Copper, brass, and copper 
alloys
ASME B16.15; ASME B16.18; ASME 
B16.22; 
ASME B16.24; 
ASME 
B16.26; 
ASME B16.51; ASTM F 
1974 
Ductile iron and gray iron
ANSI/AWWA C110/A21.10; 
AWWA C153/A21.53; ASTM A 
126; ASTM A 395; ASTM A 536; 
ASTM F 1476; ASTM F 1548
Malleable iron
ASME B16.3
PE
-
RT fittings
ASTM F 1807; ASTM F 2098; 
ASTM F 2159; ASTM F 2735; 
ASTM F 2769
PEX fittings
ASTM F 877; ASTM F 1807; ASTM 
F 2159
Plastic
ASTM D 2466; ASTM D 2467; 
ASTM F 438; ASTM F 439; ASTM 
F
877; ASTM F 2389; ASTM F 2735
HYDRONIC PIPING
Steel
ASME B16.5; ASME 
B16.9; ASME 
B16.11; ASME B16.28; ASTM A 
53/A 53M; ASTM A 106; ASTM A 
234; ASTM A 420; ASTM A 536; 
ASTM A 395; ASTM F 1476; ASTM 
F 1548
1202.6 Valves. 
Valves shall be constructed of materials that are compatible with the type of piping material and fluids 
in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration compensators. 
Flexible connectors, expansion and vibration 
control devices and fit
tings
, when used, shall protect the components of the hydronic system from damage caused by 
expansion, contraction, transverse movement, angular deflection and vibration,
shall be 
rated for the temperatures 
and pressures of the systems in which the devices
are installed, and shall be compatible with the fluid and all materials 
provided
.
SECTION 
MC 
1203
JOINTS AND CONNECTIONS
1203.1 Approval. 
Joints and connections
, other than those contained in Section 1203 and conforming to the ASTM 
standards listed in Sec
tion 1203,
shall be of an approved type. Joints and connections shall be tight for the pressure 
of the hydronic system.
1203.1.1 Joints between different piping materials. 
Joints between different piping materials shall be 
rated for 
the temperatures and pr
essures of the systems in which the devices are installed and shall be compatible with the 
fluid and all materials provided. 
1203.
1.2 Joints between dissimilar metallic piping materials.
Joints between dissimilar metallic piping mate-
rials shall be provide
d to protect against galvanic corrosion. Such joints shall be 
made with 
dielectric fittings 
conforming to ANSI B16.39 or ASTM F 492, as applicable, shall be rated for the temperatures and pressures of 
the systems in which the devices are installed and shal
l be compatible with the fluid and all materials provided
.
Exception:
Dielectric fittings shall not be required for joints between dissimilar metal piping used within heat 
transfer appliances or equipment when such joints are provided by the appliance or e
quipment manufacturer, 
and such appliance or equipment is connected with isolation valves that are accessible.
1203.2 Preparation of pipe ends. 
Pipe shall be cut square, reamed and chamfered, and shall be free of burrs and 
obstructions. Pipe ends shall hav
e full
-
bore openings and shall not be undercut.
1203.3 Joint preparation and installation. 
Where required by Sections 1203.4 through 1203.14, the preparation and 
installation of brazed, mechanical, soldered, 
solvent
-
cemented
, threaded and welded joints shall comply with Sections 
1203.3.1 through 1203.3.8.
1203.3.1 Brazed joints.
All joints 
shall
be brazed with a 
brazing procedure developed and qualified in accordance 
with the ASME
Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications) or in accord-
ance with 
AWS 
B2.2 Standard for Brazing Procedure and Performance Qualifica
tion
.
1203.3.2 Mechanical joints. 
Mechanical joints shall be installed in accordance with the manufacturer’s instruc-
tions.
1203.3.3 Soldered joints. 
Joint surfaces shall be cleaned. A flux conforming to ASTM B 813 shall be applied. The 
joint shall be solde
red with a solder conforming to ASTM B 32.
1203.3.4 Solvent
-
cemented joints. 
Joint surfaces shall be clean and free of moisture. 
A
primer
, compatible with 
both the piping material and the cement
shall be applied to pipe
-
joint surfaces
, in accordance with t
he manufac-
turer’s requirements
. Joints shall be made while the cement is wet. Solvent cement conforming to the following 
standards shall be applied to all joint surfaces:
1.
ASTM D 2235 for ABS joints.
2.
ASTM F 493 for CPVC joints.
HYDRONIC PIPING
3.
ASTM D 2564 for PVC 
joints.
1203.3.5 Threaded joints. 
Threads shall conform to ASME B1.20.1. Schedule 80 or heavier plastic pipe shall be 
threaded with dies specifically designed for plastic pipe. Thread lubricant, pipe
-
joint compound or tape shall be 
applied on the male threads only and shall be 
compatible
f
or application on the piping material
and fluid
.
1203.3.6 Welded joints.
All joints shall be welded with a welding procedure developed and qualified in accord-
ance with the 
ASME Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications
) or in 
accordance with AWS B2.1 Specifications for Welding Procedure and Performance Qualification.
1203.3.7 Grooved and shouldered mechanical joints. 
Grooved and shouldered mechanical joints shall conform 
to the requirements of ASTM F 1476 and shall be i
nstalled in accordance with the manufacturer’s
instructions.
1203.3.8 Mechanically formed tee fittings. 
Mechanically extracted outlets shall have a height not less than three 
times the thickness of the branch tube wall.
1203.3.8.1 Full flow assurance. 
Bran
ch tubes shall not restrict the flow in the run tube. A dimple/depth stop 
shall be formed in the branch tube to ensure that penetration into the outlet is of the correct depth. For inspection 
purposes, a second dimple shall be placed
1
/
4
inch (6.4 mm) above the first dimple. Dimples shall be aligned 
with the tube run.
1203.3.8.2 Brazed joints. 
Mechanically formed tee fittings shall be brazed in accordance with Section 1203.3.1.
1203.4 ABS plastic pipe. 
Joints between ABS plastic pipe or f
ittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.5 Brass pipe. 
Joints between brass pipe or fittings shall be brazed, mechanical, threaded or welded joints con-
forming to Section 1203.3.
1203.6 Brass tubing. 
Joints bet
ween brass tubing or fittings shall be brazed, mechanical or soldered joints conforming 
to Section 1203.3.
1203.7 Copper or copper
-
alloy pipe. 
Joints between copper or copper
-
alloy pipe or fittings shall be brazed, mechan-
ical, soldered, threaded or welded 
joints conforming to Section 1203.3.
1203.8 Copper or copper
-
alloy tubing. 
Joints between copper or copper
-
alloy tubing or fittings shall be brazed, 
mechanical or soldered joints conforming to Section 1203.3, flared joints conforming to Section 1203.8.1
or
push
-
fit 
joints conforming to Section 1203.8.2.
1203.8.1 Flared joints. 
Flared joints shall be made by a tool designed for that operation.
1203.8.2 Push
-
fit joints. 
Push
-
fit joints shall be installed in accordance with the manufacturer’s instructions.
120
3.9 CPVC plastic pipe.   
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.10 Reserved.
1203.11 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints between cross
-
linked polyethyle
ne plastic tubing 
and fittings shall conform to Sections 1203.11.1 and 1203.11.2. Mechanical joints shall conform to Section 1203.3.
1203.11.1 Compression
-
type fittings. 
Where
compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings 
shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.11.2 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not less 
than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same 
water line.
1203.12 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.13 Steel pipe. 
Joints between steel pipe or fittings shall be mechanical
, threaded or welded 
joints 
conforming to 
Section 1203.3.
1203.14 Steel tubing. 
Joints between steel tubing or fittings shall be mechanical or welded joints conforming to Sec-
tion 1203.3.
HYDRONIC PIPING
1203.15 Polypropylene (PP) plastic. 
Joints between PP plastic pipe and fittings shall comp
ly with Sections 1203.15.1 
and 1203.15.2.
1203.15.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylene fittings, electro
-
fusion polypropylene fittings or by butt
fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1203.15.2 Mechanical and compression sleeve joints. 
Mechanical and compression sleeve joints shal
l be installed 
in accordance with the manufacturer’s instructions.
1203.16 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyethylene 
tubing and fittings shall conform to Sections 1203.16.1 and 1203.16.2. Mechani
cal joints shall conform to Section 
1203.3.
1203.16.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.16.2 PE
-
RT
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 mm) 
of a transition from such metal pipe to PE
-
RT pipe.
1203.17 Polyethylene/aluminum/polyethylene (PE
-
AL
-
PE) pressure pipe. 
Joints between polyethylene/alumi-
num/po
lyethylene pressure pipe and fittings shall conform to Sections 1203.17.1 and 1203.17.2. Mechanical joints 
shall comply with Section 1203.3.
1203.17.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
f
ittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.17.2 PE
-
AL
-
PE
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 
mm) of a transition from such metal pipe to PE
-
AL
-
PE pipe.
1203.18 Cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe. 
Joints 
between cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene pressure pipe and fittings shall conform to 
Sections 1203.18.1 and 1203.18.2. Mecha
nical joints shall comply with Section 1203.3.
1203.18.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.18.2 PEX
-
AL
-
PEX
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches 
(457.2 mm) of a transition from such metal pipe to PEX
-
AL
-
PEX pipe.
SECTION 
MC 
1204
PIPE INSULATION
1204.1 Insulation characteristics. 
Pipe insulation installed in buildings shall conform to the requirements of the 
New 
York City
Energy Conservation Code
,
shall be tested in accordance with ASTM E 84 or UL 723, using the specimen 
preparation and mounting p
rocedures of ASTM E 2231; and shall have a maximum flame spread index of 25 and a 
smoke
-
developed index not exceeding 450. Insulation installed in an air plenum shall comply with Section 602.2.1.
1204.2 Required thickness. 
Hydronic piping shall be insulate
d to the thickness required by the 
New York City
Energy 
Conservation Code.
SECTION 
MC 
1205
VALVES
1205.1 Where required. 
Shutoff valves shall be installed in hydronic piping systems in the locations indicated in 
Sections 1205.1.1 through 1205.1.6.
1205.1.1
Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
HYDRONIC PIPING
Exception: 
Shutoff valves shall not be required where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat 
exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1205.1.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of central utility 
systems, and district
heating and cooling 
systems.
1205.1.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1205.1.4 Pressure
-
reducing valves. 
Shutoff valves shall be installed on both sides of a pressure
-
reduc
ing valve.
1205.1.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a hydronic system such as pumps, air separators, 
metering devices and si
milar equipment.
1205.1.6 Expansion tanks.
Lockable shutoff
valves shall be installed at connections to 
all
expansion tanks.
Valves shall be locked in the open position.
1205.2 Reduced pressure. 
A pressure relief valve shall be installed on the 
low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system design. 
The valve shall be installed in accordance with Section 1006.
SECTION 
MC 
1206
PIPING INSTALLATION
1
206.1 General. 
Piping, valves, fittings and connections shall be installed in accordance with the conditions of ap-
proval.
1206.2 System drain down. 
Hydronic piping systems shall be designed and installed to permit the system to be 
drained. Where the system
drains to the plumbing drainage system, the installation shall conform to the requirements 
of the 
New York City
Plumbing Code.
Exception: 
The buried portions of systems embedded underground.
1206.3 Protection of potable water. 
The potable water system sha
ll be protected from backflow in accordance with 
the 
New York City
Plumbing Code.
1206.4 Pipe penetrations. 
Openings for pipe penetrations in walls, floors or ceilings shall be larger than the penetrat-
ing pipe. Openings through concrete or masonry building
elements shall be sleeved. The annular space surrounding 
pipe penetrations shall be protected in accordance with the 
New York City
Building Code.
1206.5 Clearance to combustibles. 
A pipe in a hydronic piping system in which the exterior temperature exceed
s 
250°F (
121.1
°C) shall have a minimum clearance of 1 inch (25.4 mm) to combustible materials.
1206.6 Contact with building material. 
A hydronic piping system shall not be in direct contact with building mate-
rials that cause the piping material to degrade 
or corrode, or that interfere with the operation of the system.
1206.7 Water hammer. 
The flow velocity of the hydronic piping system shall be controlled to reduce the possibility 
of water hammer. Where a quick
-
closing valve creates water hammer, an 
enginee
red
water
-
hammer arrestor shall be 
installed. The arrestor shall be located within a range as specified by the manufacturer of the quick
-
closing valve.
1206.8 Steam piping pitch. 
Steam piping shall be installed to drain to the boiler or the steam trap. Ste
am systems 
shall not have drip pockets that reduce the capacity of the steam piping.
1206.9 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains and stresses in the pipe. 
Provisions shall be made to protect piping from damag
e resulting from expansion, contraction and structural settle-
ment. Piping shall be installed so as to avoid structural stresses or strains within building components.
1206.9.1 Flood hazard. 
Piping located in flood hazard areas 
shall comply with Appendix G
of 
the 
New York City 
Building Code
.
HYDRONIC PIPING
1206.10 Pipe support. 
Pipe shall be supported in accordance with Section 305.
Seismic supports shall be provided 
where required by the 
New York City Building Code.
1206.11 Condensation. 
Provisions shall be made to prevent the formation of condensation on the exterior of piping.
SECTION 
MC 
1207
TRANSFER FLUID
1207.1 Flash point. 
The
flash point of transfer fluid in a hydronic piping system shall be not less than 50°F (10°C) 
above the maximum system operating temperature.
1207.2 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
SECTION 
MC 
1208
TESTS
1208.1 General. 
Hydronic piping systems 
other than ground
-
source heat pump loop systems 
shall be tested hydro-
statically at one and one
half times the system design 
operating 
pressure, but not less than 100 psi (689 kPa). The 
duration of each 
test shall be not less than
2 hours. Ground
-
source heat pump loop systems shall be tested in accord-
ance with Section 1210.10.
SECTION 
MC 
1209
EMBEDDED PIPING
1209.1 Materials. 
Embedded piping
shall be plastic pipe or tubing
, in accordance with Section 1202
,
rated at 100 psi 
(689.5 kPa) at 180°F (82.2°C).
1209.2 Pressurizing during installation. 
Piping to be embedded in concrete shall be pressure tested prior to pouring 
concrete. During pouring, the pipe shall be maintained at the proposed operating pressure
.
1209.3 Embedded joints. 
Joints of pipe or tubing that are embedded in a portion of the building, such as concrete or 
plaster, shall be thermally
-
fused.
1209.4 Not embedded related piping. 
Joints of other piping in cavities or running exposed shall be joi
ned in accord-
ance with manufacturer’s instructions and related sections of this code.
1209.5 Thermal barrier required. 
Radiant floor heating systems shall be provided with a thermal barrier in accord-
ance with Sections 1209.5.1 through 1209.5.4.
Exception: 
Insulation shall not be required in engineered systems where it can be demonstrated that the insulation 
will decrease the efficiency or have a negative effect on the installation.
1209.5.1 Slab
-
on
-
grade installation. 
Radiant piping utilized in slab
-
on
-
grad
e applications shall be provided with 
insulating materials installed beneath the piping having a minimum R
-
value of 5.
1209.5.2 Suspended floor installation. 
In suspended floor applications, insulation shall be installed in the joist 
bay cavity serving the
heating space above and shall consist of materials having a minimum R
-
value of 11.
1209.5.3 Thermal break required. 
A thermal break shall be provided consisting of asphalt expansion joint mate-
rials or similar insulating materials at a point where a heated
slab meets a foundation wall or other conductive slab.
1209.5.4 Thermal barrier material marking. 
Insulating materials utilized in thermal barriers shall be installed 
such that the manufacturer’s R
-
value mark is readily observable upon inspection.
SECTION
MC 
1210
PLASTIC PIPE GROUND
-
SOURCE HEAT PUMP LOOP SYSTEMS
HYDRONIC PIPING
1210.1 Ground
-
source heat pump
-
loop water piping. 
Ground
-
source heat pump ground
-
loop piping and tubing 
material for water
-
based systems shall conform to the standards cited in this section.
1210.2
Used materials. 
Reused pipe, fittings, valves, and other materials shall not be permitted in ground
-
source heat 
pump loop systems.
1210.3 Material rating. 
Pipe and tubing shall be rated for the operating temperature and pressure of the ground
-
source heat 
pump loop system. Fittings shall be suitable for the pressure applications and recommended by the man-
ufacturer for installation with the pipe and tubing material installed. Where used underground, materials shall be suit-
able for burial.
1210.4 Piping and t
ubing materials standards. 
Ground
-
source heat pump ground
-
loop pipe and tubing shall con-
form to the standards listed in Table 1210.4.
TABLE 1210.4
GROUND
-
SOURCE LOOP PIPE
MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl chloride 
(CPVC)
ASTM D 
2846; ASTM F 
441; ASTM F 442
Cross
-
linked polyethylene (PEX)
ASTM F 876; ASTM F 877; 
CSA B137.5
Polyethylene/aluminum/polyethylen
e (PE
-
AL
-
PE) pressure pipe
ASTM F 1282; CSA B137.9
High
-
density polyethylene (HDPE)
ASTM D 2737; ASTM D 
3035; ASTM F 
714; AWWA 
C901; CSA B137.1; CSA 
C448; NSF 358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl chloride (PVC)
ASTM D 1785; ASTM D 
2241
Raised temperature polyethylene 
(PE
-
RT)
ASTM F 2623
1210.5 Fittings. 
Ground
-
source heat pump pipe fittings shall conform to the standards listed in Table 1210.5 and, if 
installed underground, shall be suitable for burial. 
TABLE 1210.5
GROUND
-
SOURCE LOOP PIPE FITTINGS
PIPE MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl 
chloride (CPVC)
ASTM D 2846; ASTM F 437; ASTM F 
438; ASTM F 439; CSA B137.6
Cross
-
linked 
polyethylene (PEX)
ASTM F 877; ASTM F 1807; ASTM F 
1960; ASTM F 2080; ASTM F 2159; 
ASTM F 2434; CSA B137.5
Polyethylene/aluminum/
polyethylene (PE
-
AL
-
PE)
ASTM F 1282; ASTM F 2434; CSA 
B137.9
HYDRONIC PIPING
High Density 
Polyethylene (HDPE)
ASTM D 2683; ASTM D 3261; ASTM 
F 1055; CSA B137.1; CSA C448; NSF 
358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl 
chloride 
(PVC)
ASTM D 2464; ASTM D 2466; ASTM 
D 2467; CSA B137.2; CSA B137.3
Raised temperature 
polyethylene (PE
-
RT)
ASTM D 3261; ASTM F 1807; ASTM 
F 2159; CSA B137.1
1210.6 Joints. 
Joints and connections, 
other than those covered by Section 1210 and co
nforming to the ASTM stand-
ards listed therein,
shall be of an approved type. Joints and connections shall be tight for the pressure of the ground
-
source loop system. Joints used underground shall be in accordance with manufacturer’s instructions for buried
appli-
cations.
1210.6.1 Joints between different piping materials. 
Joints between different piping materials shall be made with 
transition fittings compatible with both materials and the fluid contained within the system. Transition fittings must 
be used i
n accordance with manufacturer’s instructions.
1210.6.1.1 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not 
less than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same water line.
1210.6.2 Prep
aration of pipe ends. 
Pipe shall be cut square, be reamed, and be free of burrs and obstructions. 
CPVC, PE, and PVC pipe shall be chamfered. Pipe ends shall have full
-
bore openings and shall not be undercut.
1210.6.3 Joint preparation and installation. 
Whe
re required by Sections 1210.6.4 through 1210.6.6, the prepa-
ration and installation of mechanical and thermoplastic
-
welded joints shall comply with Sections 1210.6.3.1 and 
1210.6.3.2.
1210.6.3.1 Mechanical joints. 
Mechanical joints shall be installed in ac
cordance with the manufacturer’s in-
structions.
1210.6.3.2 Thermoplastic
-
welded joints. 
Joint surfaces for thermoplastic
-
welded joints shall be cleaned by a 
procedure in accordance with the manufacturer’s instructions. Joints shall be welded in accordance w
ith the 
manufacturer’s instructions.
1210.6.4 CPVC plastic pipe. 
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded 
joints complying with Section 1203.3.
‡‡‡
1210.6.5 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints bet
ween cross
-
linked polyethylene plastic 
tubing and fittings shall comply with Section 1210.6.5.1. Mechanical joints shall comply with Section 1210.6.3.
1210.6.5.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
r
ings, 
the fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1210.6.6 Polyethylene plastic pipe and tubing for ground
-
source heat pump loop systems. 
Joints between 
polyethylene plastic pipe and tubing or fittings for 
ground
-
source heat pump loop systems shall be heat fusion 
joints complying with Section 1210.6.6.1, electrofusion joints complying with Section 1210.6.6.2, or stab
-
type 
insertion joints complying with Section 1210.6.6.3.
1210.6.6.1 Heat
-
fusion joints. 
Joints shall be of the socket
-
fusion, saddle
-
fusion or butt
-
fusion type, joined in 
accordance with ASTM D 2657. Joint surfaces shall be clean and free from moisture. Joint surfaces shall be 
heated to melt temperatures and joi
ned. The joint shall be undisturbed until cool. Fittings shall be manufactured 
in accordance with ASTM D 2683 or ASTM D 3261.
1210.6.6.2 Electrofusion joints. 
Joints shall be of the electrofusion type. Joint surfaces shall be clean and free 
from moisture, 
and scoured to expose virgin resin. Joint surfaces shall be heated to melt temperatures for the 
HYDRONIC PIPING
period of time specified by the manufacturer. The joint shall be undisturbed until cool. Fittings shall be manu-
factured in accordance with ASTM F 1055.
1210.6.6
.3 Stab
-
type insert fittings. 
Joint surfaces shall be clean and free from moisture. Pipe ends shall be 
chamfered and inserted into the fittings to full depth. Fittings shall be manufactured in accordance with ASTM 
F 1924.
1210.6.7 Polypropylene (PP) plasti
c. 
Joints between PP plastic pipe and fittings shall comply with Sections 
1210.6.7.1 and 1210.6.7.2.
1210.6.7.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylen
e fittings, electrofusion polypropylene fittings or by butt fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1210.6.7.2 Mechanical and compression 
sleeve joints. 
Mechanical and compression sleeve joints shall be 
installed in accordance with the manufacturer’s instructions.
1210.6.8 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyeth-
ylene tubing and fittin
gs shall comply with Sections 1210.6.8.1 and 1210.6.8.2. Mechanical joints shall comply 
with Section 1210.6.3.
1210.6.8.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, 
the fittings shall be installed wi
thout omitting the inserts and ferrules or O
-
rings.
1210.6.9 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded 
joints comply with Section 1203.3.
1210.7 Shutoff valves. 
Shutoff valves shall be installed in
ground
-
source loop piping systems in the locations indi-
cated in Sections 1210.7.1 through 1210.7.7.
1210.7.1 Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
Exception: 
Shutoff valves shall not be requi
red where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1210
.7.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of a central utility 
system.
1210.7.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1210.7.4 Pressure
-
reducing valves.
Shutoff valves shall be installed on both sides of a pressure
-
reducing valve.
1210.7.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a gr
ound
-
source loop system such as pumps, air 
separators, metering devices, and similar equipment.
1210.7.6 Expansion tanks. 
Shutoff valves shall be installed at connections to nondiaphragm
-
type expansion tanks.
1210.7.7 Reduced pressure. 
A pressure relief va
lve shall be installed on the low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system 
design. The valve shall be installed in accordance with Section 1006.
1210.8 
Installation. 
Piping, valves, fittings, and connections shall be installed in accordance with the 
conditions of approval.
1210.8.1 Protection of potable water. 
Where ground
-
source heat pump ground
-
loop systems have a connection 
to a potable water supply, t
he potable water system shall be protected from backflow in accordance with the 
New 
York City Plumbing Code
.
1210.8.2 Pipe penetrations. 
Openings for pipe penetrations in walls, floors and ceilings shall be larger than the 
penetrating pipe. Openings throug
h concrete or masonry building elements shall be sleeved. The annular space 
surrounding pipe penetrations shall be protected in accordance with the 
New York City Building Code
.
HYDRONIC PIPING
1210.8.3 Clearance from combustibles. 
A pipe in a ground
-
source heat pump pipin
g system having an exterior 
surface temperature exceeding 250°F (121.1°C) shall have a minimum clearance of 1 inch (25.4 mm) from com-
bustible materials.
1210.8.4 Contact with building material. 
A ground
-
source heat pump ground
-
loop piping system shall not 
be in 
direct contact with building materials that cause the piping or fitting material to degrade or corrode, or that interfere 
with the operation of the system.
1210.8.5 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains 
and stresses in the pipe. 
Provisions shall be made to protect piping from damage resulting from expansion, contraction and structural set-
tlement. Piping shall be installed so as to avoid structural stresses or strains within building components.
1210.8.6 F
lood hazard. 
Piping located in a flood hazard area shall be capable of resisting hydrostatic and hydro-
dynamic loads and stresses, including the effects of buoyancy, during the occurrence of flooding to the design flood 
elevation.
1210.8.7 Pipe support. 
Pip
e shall be supported in accordance with Section 305.
1210.8.8 Velocities. 
Ground
-
source heat pump ground
-
loop systems shall be designed so that the flow velocities 
do not exceed the maximum flow velocity recommended by the pipe and fittings 
manufacturer and shall be con-
trolled to reduce the possibility of water hammer.
1210.8.9 Labeling and marking. 
Ground
-
source heat pump ground
-
loop system piping shall be marked with tape, 
metal tags or other method where it enters a building indicating “GR
OUND
-
SOURCE HEAT PUMP LOOP SYS-
TEM.” The marking shall indicate any antifreeze used in the system by name and concentration.
1210.8.10 Chemical compatibility. 
Antifreeze and other materials used in the system shall be chemically compat-
ible with the 
pipe, tubing, fittings, and mechanical systems.
1210.9 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
1210.10 Tests. 
Before connection header trenches are backfilled, the assembled loop system shall be pr
essure tested 
with water at 100 psi (689.5 kPa) for 15 minutes, in which time there shall not be observed leaks. Flow and pressure 
loss testing shall be performed and the actual flow rates and pressure drops shall be compared to the calculated design 
value
s. If actual flow rate or pressure drop values differ from calculated design values by more than 10 percent, the 
cause shall be identified and corrective action taken.
1210.11 Embedded piping. 
Ground
-
source heat pump ground
-
loop piping to be embedded in co
ncrete shall be pres-
sure tested prior to pouring concrete. During pouring, the pipe shall be maintained at the proposed operating pressure. 
Embedded piping shall comply with Section 1209.
SECTION MC 1211
HIGH
-
PRESSURE STEAM AND
HIGH TEMPERATURE HOT WATER P
IPING SYSTEMS
1211.1 Scope.
The provisions of this section shall apply to high
-
pressure steam piping system, which is defined as a 
system operating at a steam pressure of more than 15 psi (103.4 kPa), and high temperature water intended for 
operation at pr
essures in excess of 160 psi (1103.2 kPa) and temperatures in excess of 250°F (121.1°C). For purposes 
of this section, loops, bends or offsets of the piping shall not be considered expansion joints.
1211.2 New systems.
For purposes of this section, the rep
lacement of existing steam piping systems, the installation 
of a new system in existing buildings, as well as installations in buildings hereafter constructed, shall be considered 
to be new high
-
pressure steam piping systems. The following requirements are
applicable:
1211.2.1 Design.
The design of new steam piping systems shall be conducted as follows:
1.
The system shall be designed by an engineer. An application and plans shall be filed and the approval of the 
department obtained. The plans and applicati
on shall contain, but not be limited to, the following information:
1.1.
Size and location of all steam piping.
HYDRONIC PIPING
1.2.
The operating pressures and temperatures.
1.3.
The location, type, specifications and details of all expansion joints.
1.4.
The design, siz
e, material and location of all anchors, guides and auxiliary steel, and the stresses thereon.
2.
Systems using utility street steam shall be designed for a pressure of 200 psig (1379 kPa) and 413°F (211.7°C) 
up to and including the steam pressure reducing
valve or valves which reduce the pressure of 90 psig (620.5 
kPa) or below. For steam pressures between 90 psig (620.5 kPa) and 16 psig (110.3 kPa), the system shall be 
designed for 125 psig (861.8 kPa).
3.
Steam distribution systems utilizing pressure red
ucing valves.
3.1.
Safety Shutoff Valves (SSO) to protect downstream piping from overpressure shall be allowed in lieu of 
a safety relief valve vented to the outdoors as required by Section 1006.6.
3.2.
SSO shall be designed to automatically close at or be
low the design pressure of the downstream piping 
system that is being protected, to provide positive shutoff against full upstream pressure. Manual reset 
shall be required to reopen the SSO.
3.3.
SSO shall be designed in accordance with the Steam Distribut
ion Utility System requirements of the 
utility company having jurisdiction and ASME B31.1.
4.
Bellows expansion joints shall not be utilized on high pressure steam piping.
Exception: 
Bellows expansion joints shall be permitted for final connection to equip
ment where readily 
accessible for inspection and service and within Mechanical Equipment Rooms.
1211.2.2 Installation.
The installation of new steam piping systems shall be conducted as follows:
1.
Installations, including any welding, shall be subject to 
special inspection.
2.
Welders shall be qualified for all required pipe sizes, wall thicknesses and positions in accordance with the 
ASME
Boiler and Pressure Vessel Code,
Section IX. Requalification is required every five years or sooner 
if the commissione
r has a specific reason to doubt a welder’s ability to make acceptable welds.
3.
Welder qualification testing shall be performed by an approved agency listed with the department, and the 
inspector witnessing the test shall be an authorized AWS Certified We
lding Inspector. If the testing is by 
radiography, the test specimen shall be evaluated by personnel having a minimum radiography qualification 
of Level II in accordance with the ASNT, Document No. SNT
-
TC
-
1A, Supplement A. A successful radio-
graphic test of
a production weld made within the 6 months prior to requalification may be considered as an 
acceptable requalification test.
4.
Copies of the certified welder qualification reports shall be maintained by the responsible welding agency 
and the company perf
orming the welding, and shall be made available upon request to the department.
5.
No reports from any welding inspection agency shall be accepted unless such agency has first requested and 
obtained approval from the department in accordance with rules of 
the department.
6.
Pipe welding shall conform to the following:
6.1.
All piping over 2 inches (
50.8
mm) shall be butt
-
welded. Piping 2 inches (50.8 mm) and under may be 
socket
-
welded or threaded, providing Schedule 80 piping is utilized.
6.2.
Threaded piping may continue to be used for existing construction in size of 6 inches (
152.4
mm) and 
under.
6.3.
Where welding is not feasible, the commissioner may allow an acceptable alternative.
7.
Radiographic examination, when required, shall be performed on butt
-
welds in accordance with ASME 
B31.1 based on the piping system design pressure and shall be as foll
ows:
Piping System Design Pressure
Percentage
90 psig (620.5 kPa) or below
Not RequiredB31.
1 and ASME B31.9, as applicable
. 
SECTION 
MC 
1202
MATERIAL
1202.1 Piping. 
Piping material, other than those contained within this section and conforming with the ASTM stand-
ards listed within this chapter, shall be of an approved type.
Exception: 
Embedded piping regulated by Section 1209, and ground
-
source heat pump loop systems regulated by 
Section 1210.
1202.2 Used existing materials. 
Reused pipe, fittings, valves or other materials shall be clean and free of foreign 
materials.
1202.3 Material rating. 
Materials shall be rated for the operating temperature and pressure of the hydronic system. 
Materials shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards. 
Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior 
of the pipe shall be protected from corrosion and d
egradation.
TABLE 1202.4
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene 
(ABS) plastic pipe
ASTM D 1527; ASTM F 2806
Chlorinated polyvinyl chloride 
(CPVC) plastic pipe
ASTM D 2846; ASTM F 441; 
ASTM F 442
Copper, 
brass, or copper
-
alloy 
pipe
ASTM B 42; ASTM B 43; 
ASTM B 302
Copper, brass, or copper
-
alloy 
tube (Type K, L or M)
ASTM B 75; ASTM B 88; 
ASTM B 135; ASTM B 251
HYDRONIC PIPING
Cross
-
linked 
polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe
ASTM F 1281; CSA
B137.10
Cross
-
linked polyethylene 
(PEX) tubing
ASTM F 876; ASTM F 877
Ductile iron pipe
AWWA C115/A21.15; AWWA 
C151/A21.51 
Polyethylene/aluminum/
polyet
hylene 
(PE
-
AL
-
PE) pressure 
pipe
ASTM F 1282; CSA B137.9
Polypropylene (PP) 
plastic pipe
ASTM F 2389
Polyvinyl chloride (PVC) 
plastic pipe
ASTM D 1785; ASTM D 2241
Raised temperature 
polyethylene (PE
-
RT)
ASTM F 2623; ASTM F 2769
Steel pipe
ASTM A 53/A 53M; ASTM A 
106
Steel tubing
ASTM A 254
1202.5 Pipe fittings. 
Hydronic pipe fittings shall conform to the respective pipe standards or to the standards listed in 
Table 1202.5.
TABLE 1202.5
HYDRONIC PIPE FITTINGS
MATERIAL
STANDARD (see Chapter 15)
Copper, brass, and copper 
alloys
ASME B16.15; ASME B16.18; ASME 
B16.22; 
ASME B16.24; 
ASME 
B16.26; 
ASME B16.51; ASTM F 
1974 
Ductile iron and gray iron
ANSI/AWWA C110/A21.10; 
AWWA C153/A21.53; ASTM A 
126; ASTM A 395; ASTM A 536; 
ASTM F 1476; ASTM F 1548
Malleable iron
ASME B16.3
PE
-
RT fittings
ASTM F 1807; ASTM F 2098; 
ASTM F 2159; ASTM F 2735; 
ASTM F 2769
PEX fittings
ASTM F 877; ASTM F 1807; ASTM 
F 2159
Plastic
ASTM D 2466; ASTM D 2467; 
ASTM F 438; ASTM F 439; ASTM 
F
877; ASTM F 2389; ASTM F 2735
HYDRONIC PIPING
Steel
ASME B16.5; ASME 
B16.9; ASME 
B16.11; ASME B16.28; ASTM A 
53/A 53M; ASTM A 106; ASTM A 
234; ASTM A 420; ASTM A 536; 
ASTM A 395; ASTM F 1476; ASTM 
F 1548
1202.6 Valves. 
Valves shall be constructed of materials that are compatible with the type of piping material and fluids 
in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration compensators. 
Flexible connectors, expansion and vibration 
control devices and fit
tings
, when used, shall protect the components of the hydronic system from damage caused by 
expansion, contraction, transverse movement, angular deflection and vibration,
shall be 
rated for the temperatures 
and pressures of the systems in which the devices
are installed, and shall be compatible with the fluid and all materials 
provided
.
SECTION 
MC 
1203
JOINTS AND CONNECTIONS
1203.1 Approval. 
Joints and connections
, other than those contained in Section 1203 and conforming to the ASTM 
standards listed in Sec
tion 1203,
shall be of an approved type. Joints and connections shall be tight for the pressure 
of the hydronic system.
1203.1.1 Joints between different piping materials. 
Joints between different piping materials shall be 
rated for 
the temperatures and pr
essures of the systems in which the devices are installed and shall be compatible with the 
fluid and all materials provided. 
1203.
1.2 Joints between dissimilar metallic piping materials.
Joints between dissimilar metallic piping mate-
rials shall be provide
d to protect against galvanic corrosion. Such joints shall be 
made with 
dielectric fittings 
conforming to ANSI B16.39 or ASTM F 492, as applicable, shall be rated for the temperatures and pressures of 
the systems in which the devices are installed and shal
l be compatible with the fluid and all materials provided
.
Exception:
Dielectric fittings shall not be required for joints between dissimilar metal piping used within heat 
transfer appliances or equipment when such joints are provided by the appliance or e
quipment manufacturer, 
and such appliance or equipment is connected with isolation valves that are accessible.
1203.2 Preparation of pipe ends. 
Pipe shall be cut square, reamed and chamfered, and shall be free of burrs and 
obstructions. Pipe ends shall hav
e full
-
bore openings and shall not be undercut.
1203.3 Joint preparation and installation. 
Where required by Sections 1203.4 through 1203.14, the preparation and 
installation of brazed, mechanical, soldered, 
solvent
-
cemented
, threaded and welded joints shall comply with Sections 
1203.3.1 through 1203.3.8.
1203.3.1 Brazed joints.
All joints 
shall
be brazed with a 
brazing procedure developed and qualified in accordance 
with the ASME
Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications) or in accord-
ance with 
AWS 
B2.2 Standard for Brazing Procedure and Performance Qualifica
tion
.
1203.3.2 Mechanical joints. 
Mechanical joints shall be installed in accordance with the manufacturer’s instruc-
tions.
1203.3.3 Soldered joints. 
Joint surfaces shall be cleaned. A flux conforming to ASTM B 813 shall be applied. The 
joint shall be solde
red with a solder conforming to ASTM B 32.
1203.3.4 Solvent
-
cemented joints. 
Joint surfaces shall be clean and free of moisture. 
A
primer
, compatible with 
both the piping material and the cement
shall be applied to pipe
-
joint surfaces
, in accordance with t
he manufac-
turer’s requirements
. Joints shall be made while the cement is wet. Solvent cement conforming to the following 
standards shall be applied to all joint surfaces:
1.
ASTM D 2235 for ABS joints.
2.
ASTM F 493 for CPVC joints.
HYDRONIC PIPING
3.
ASTM D 2564 for PVC 
joints.
1203.3.5 Threaded joints. 
Threads shall conform to ASME B1.20.1. Schedule 80 or heavier plastic pipe shall be 
threaded with dies specifically designed for plastic pipe. Thread lubricant, pipe
-
joint compound or tape shall be 
applied on the male threads only and shall be 
compatible
f
or application on the piping material
and fluid
.
1203.3.6 Welded joints.
All joints shall be welded with a welding procedure developed and qualified in accord-
ance with the 
ASME Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications
) or in 
accordance with AWS B2.1 Specifications for Welding Procedure and Performance Qualification.
1203.3.7 Grooved and shouldered mechanical joints. 
Grooved and shouldered mechanical joints shall conform 
to the requirements of ASTM F 1476 and shall be i
nstalled in accordance with the manufacturer’s
instructions.
1203.3.8 Mechanically formed tee fittings. 
Mechanically extracted outlets shall have a height not less than three 
times the thickness of the branch tube wall.
1203.3.8.1 Full flow assurance. 
Bran
ch tubes shall not restrict the flow in the run tube. A dimple/depth stop 
shall be formed in the branch tube to ensure that penetration into the outlet is of the correct depth. For inspection 
purposes, a second dimple shall be placed
1
/
4
inch (6.4 mm) above the first dimple. Dimples shall be aligned 
with the tube run.
1203.3.8.2 Brazed joints. 
Mechanically formed tee fittings shall be brazed in accordance with Section 1203.3.1.
1203.4 ABS plastic pipe. 
Joints between ABS plastic pipe or f
ittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.5 Brass pipe. 
Joints between brass pipe or fittings shall be brazed, mechanical, threaded or welded joints con-
forming to Section 1203.3.
1203.6 Brass tubing. 
Joints bet
ween brass tubing or fittings shall be brazed, mechanical or soldered joints conforming 
to Section 1203.3.
1203.7 Copper or copper
-
alloy pipe. 
Joints between copper or copper
-
alloy pipe or fittings shall be brazed, mechan-
ical, soldered, threaded or welded 
joints conforming to Section 1203.3.
1203.8 Copper or copper
-
alloy tubing. 
Joints between copper or copper
-
alloy tubing or fittings shall be brazed, 
mechanical or soldered joints conforming to Section 1203.3, flared joints conforming to Section 1203.8.1
or
push
-
fit 
joints conforming to Section 1203.8.2.
1203.8.1 Flared joints. 
Flared joints shall be made by a tool designed for that operation.
1203.8.2 Push
-
fit joints. 
Push
-
fit joints shall be installed in accordance with the manufacturer’s instructions.
120
3.9 CPVC plastic pipe.   
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.10 Reserved.
1203.11 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints between cross
-
linked polyethyle
ne plastic tubing 
and fittings shall conform to Sections 1203.11.1 and 1203.11.2. Mechanical joints shall conform to Section 1203.3.
1203.11.1 Compression
-
type fittings. 
Where
compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings 
shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.11.2 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not less 
than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same 
water line.
1203.12 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.13 Steel pipe. 
Joints between steel pipe or fittings shall be mechanical
, threaded or welded 
joints 
conforming to 
Section 1203.3.
1203.14 Steel tubing. 
Joints between steel tubing or fittings shall be mechanical or welded joints conforming to Sec-
tion 1203.3.
HYDRONIC PIPING
1203.15 Polypropylene (PP) plastic. 
Joints between PP plastic pipe and fittings shall comp
ly with Sections 1203.15.1 
and 1203.15.2.
1203.15.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylene fittings, electro
-
fusion polypropylene fittings or by butt
fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1203.15.2 Mechanical and compression sleeve joints. 
Mechanical and compression sleeve joints shal
l be installed 
in accordance with the manufacturer’s instructions.
1203.16 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyethylene 
tubing and fittings shall conform to Sections 1203.16.1 and 1203.16.2. Mechani
cal joints shall conform to Section 
1203.3.
1203.16.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.16.2 PE
-
RT
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 mm) 
of a transition from such metal pipe to PE
-
RT pipe.
1203.17 Polyethylene/aluminum/polyethylene (PE
-
AL
-
PE) pressure pipe. 
Joints between polyethylene/alumi-
num/po
lyethylene pressure pipe and fittings shall conform to Sections 1203.17.1 and 1203.17.2. Mechanical joints 
shall comply with Section 1203.3.
1203.17.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
f
ittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.17.2 PE
-
AL
-
PE
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 
mm) of a transition from such metal pipe to PE
-
AL
-
PE pipe.
1203.18 Cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe. 
Joints 
between cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene pressure pipe and fittings shall conform to 
Sections 1203.18.1 and 1203.18.2. Mecha
nical joints shall comply with Section 1203.3.
1203.18.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.18.2 PEX
-
AL
-
PEX
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches 
(457.2 mm) of a transition from such metal pipe to PEX
-
AL
-
PEX pipe.
SECTION 
MC 
1204
PIPE INSULATION
1204.1 Insulation characteristics. 
Pipe insulation installed in buildings shall conform to the requirements of the 
New 
York City
Energy Conservation Code
,
shall be tested in accordance with ASTM E 84 or UL 723, using the specimen 
preparation and mounting p
rocedures of ASTM E 2231; and shall have a maximum flame spread index of 25 and a 
smoke
-
developed index not exceeding 450. Insulation installed in an air plenum shall comply with Section 602.2.1.
1204.2 Required thickness. 
Hydronic piping shall be insulate
d to the thickness required by the 
New York City
Energy 
Conservation Code.
SECTION 
MC 
1205
VALVES
1205.1 Where required. 
Shutoff valves shall be installed in hydronic piping systems in the locations indicated in 
Sections 1205.1.1 through 1205.1.6.
1205.1.1
Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
HYDRONIC PIPING
Exception: 
Shutoff valves shall not be required where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat 
exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1205.1.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of central utility 
systems, and district
heating and cooling 
systems.
1205.1.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1205.1.4 Pressure
-
reducing valves. 
Shutoff valves shall be installed on both sides of a pressure
-
reduc
ing valve.
1205.1.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a hydronic system such as pumps, air separators, 
metering devices and si
milar equipment.
1205.1.6 Expansion tanks.
Lockable shutoff
valves shall be installed at connections to 
all
expansion tanks.
Valves shall be locked in the open position.
1205.2 Reduced pressure. 
A pressure relief valve shall be installed on the 
low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system design. 
The valve shall be installed in accordance with Section 1006.
SECTION 
MC 
1206
PIPING INSTALLATION
1
206.1 General. 
Piping, valves, fittings and connections shall be installed in accordance with the conditions of ap-
proval.
1206.2 System drain down. 
Hydronic piping systems shall be designed and installed to permit the system to be 
drained. Where the system
drains to the plumbing drainage system, the installation shall conform to the requirements 
of the 
New York City
Plumbing Code.
Exception: 
The buried portions of systems embedded underground.
1206.3 Protection of potable water. 
The potable water system sha
ll be protected from backflow in accordance with 
the 
New York City
Plumbing Code.
1206.4 Pipe penetrations. 
Openings for pipe penetrations in walls, floors or ceilings shall be larger than the penetrat-
ing pipe. Openings through concrete or masonry building
elements shall be sleeved. The annular space surrounding 
pipe penetrations shall be protected in accordance with the 
New York City
Building Code.
1206.5 Clearance to combustibles. 
A pipe in a hydronic piping system in which the exterior temperature exceed
s 
250°F (
121.1
°C) shall have a minimum clearance of 1 inch (25.4 mm) to combustible materials.
1206.6 Contact with building material. 
A hydronic piping system shall not be in direct contact with building mate-
rials that cause the piping material to degrade 
or corrode, or that interfere with the operation of the system.
1206.7 Water hammer. 
The flow velocity of the hydronic piping system shall be controlled to reduce the possibility 
of water hammer. Where a quick
-
closing valve creates water hammer, an 
enginee
red
water
-
hammer arrestor shall be 
installed. The arrestor shall be located within a range as specified by the manufacturer of the quick
-
closing valve.
1206.8 Steam piping pitch. 
Steam piping shall be installed to drain to the boiler or the steam trap. Ste
am systems 
shall not have drip pockets that reduce the capacity of the steam piping.
1206.9 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains and stresses in the pipe. 
Provisions shall be made to protect piping from damag
e resulting from expansion, contraction and structural settle-
ment. Piping shall be installed so as to avoid structural stresses or strains within building components.
1206.9.1 Flood hazard. 
Piping located in flood hazard areas 
shall comply with Appendix G
of 
the 
New York City 
Building Code
.
HYDRONIC PIPING
1206.10 Pipe support. 
Pipe shall be supported in accordance with Section 305.
Seismic supports shall be provided 
where required by the 
New York City Building Code.
1206.11 Condensation. 
Provisions shall be made to prevent the formation of condensation on the exterior of piping.
SECTION 
MC 
1207
TRANSFER FLUID
1207.1 Flash point. 
The
flash point of transfer fluid in a hydronic piping system shall be not less than 50°F (10°C) 
above the maximum system operating temperature.
1207.2 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
SECTION 
MC 
1208
TESTS
1208.1 General. 
Hydronic piping systems 
other than ground
-
source heat pump loop systems 
shall be tested hydro-
statically at one and one
half times the system design 
operating 
pressure, but not less than 100 psi (689 kPa). The 
duration of each 
test shall be not less than
2 hours. Ground
-
source heat pump loop systems shall be tested in accord-
ance with Section 1210.10.
SECTION 
MC 
1209
EMBEDDED PIPING
1209.1 Materials. 
Embedded piping
shall be plastic pipe or tubing
, in accordance with Section 1202
,
rated at 100 psi 
(689.5 kPa) at 180°F (82.2°C).
1209.2 Pressurizing during installation. 
Piping to be embedded in concrete shall be pressure tested prior to pouring 
concrete. During pouring, the pipe shall be maintained at the proposed operating pressure
.
1209.3 Embedded joints. 
Joints of pipe or tubing that are embedded in a portion of the building, such as concrete or 
plaster, shall be thermally
-
fused.
1209.4 Not embedded related piping. 
Joints of other piping in cavities or running exposed shall be joi
ned in accord-
ance with manufacturer’s instructions and related sections of this code.
1209.5 Thermal barrier required. 
Radiant floor heating systems shall be provided with a thermal barrier in accord-
ance with Sections 1209.5.1 through 1209.5.4.
Exception: 
Insulation shall not be required in engineered systems where it can be demonstrated that the insulation 
will decrease the efficiency or have a negative effect on the installation.
1209.5.1 Slab
-
on
-
grade installation. 
Radiant piping utilized in slab
-
on
-
grad
e applications shall be provided with 
insulating materials installed beneath the piping having a minimum R
-
value of 5.
1209.5.2 Suspended floor installation. 
In suspended floor applications, insulation shall be installed in the joist 
bay cavity serving the
heating space above and shall consist of materials having a minimum R
-
value of 11.
1209.5.3 Thermal break required. 
A thermal break shall be provided consisting of asphalt expansion joint mate-
rials or similar insulating materials at a point where a heated
slab meets a foundation wall or other conductive slab.
1209.5.4 Thermal barrier material marking. 
Insulating materials utilized in thermal barriers shall be installed 
such that the manufacturer’s R
-
value mark is readily observable upon inspection.
SECTION
MC 
1210
PLASTIC PIPE GROUND
-
SOURCE HEAT PUMP LOOP SYSTEMS
HYDRONIC PIPING
1210.1 Ground
-
source heat pump
-
loop water piping. 
Ground
-
source heat pump ground
-
loop piping and tubing 
material for water
-
based systems shall conform to the standards cited in this section.
1210.2
Used materials. 
Reused pipe, fittings, valves, and other materials shall not be permitted in ground
-
source heat 
pump loop systems.
1210.3 Material rating. 
Pipe and tubing shall be rated for the operating temperature and pressure of the ground
-
source heat 
pump loop system. Fittings shall be suitable for the pressure applications and recommended by the man-
ufacturer for installation with the pipe and tubing material installed. Where used underground, materials shall be suit-
able for burial.
1210.4 Piping and t
ubing materials standards. 
Ground
-
source heat pump ground
-
loop pipe and tubing shall con-
form to the standards listed in Table 1210.4.
TABLE 1210.4
GROUND
-
SOURCE LOOP PIPE
MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl chloride 
(CPVC)
ASTM D 
2846; ASTM F 
441; ASTM F 442
Cross
-
linked polyethylene (PEX)
ASTM F 876; ASTM F 877; 
CSA B137.5
Polyethylene/aluminum/polyethylen
e (PE
-
AL
-
PE) pressure pipe
ASTM F 1282; CSA B137.9
High
-
density polyethylene (HDPE)
ASTM D 2737; ASTM D 
3035; ASTM F 
714; AWWA 
C901; CSA B137.1; CSA 
C448; NSF 358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl chloride (PVC)
ASTM D 1785; ASTM D 
2241
Raised temperature polyethylene 
(PE
-
RT)
ASTM F 2623
1210.5 Fittings. 
Ground
-
source heat pump pipe fittings shall conform to the standards listed in Table 1210.5 and, if 
installed underground, shall be suitable for burial. 
TABLE 1210.5
GROUND
-
SOURCE LOOP PIPE FITTINGS
PIPE MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl 
chloride (CPVC)
ASTM D 2846; ASTM F 437; ASTM F 
438; ASTM F 439; CSA B137.6
Cross
-
linked 
polyethylene (PEX)
ASTM F 877; ASTM F 1807; ASTM F 
1960; ASTM F 2080; ASTM F 2159; 
ASTM F 2434; CSA B137.5
Polyethylene/aluminum/
polyethylene (PE
-
AL
-
PE)
ASTM F 1282; ASTM F 2434; CSA 
B137.9
HYDRONIC PIPING
High Density 
Polyethylene (HDPE)
ASTM D 2683; ASTM D 3261; ASTM 
F 1055; CSA B137.1; CSA C448; NSF 
358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl 
chloride 
(PVC)
ASTM D 2464; ASTM D 2466; ASTM 
D 2467; CSA B137.2; CSA B137.3
Raised temperature 
polyethylene (PE
-
RT)
ASTM D 3261; ASTM F 1807; ASTM 
F 2159; CSA B137.1
1210.6 Joints. 
Joints and connections, 
other than those covered by Section 1210 and co
nforming to the ASTM stand-
ards listed therein,
shall be of an approved type. Joints and connections shall be tight for the pressure of the ground
-
source loop system. Joints used underground shall be in accordance with manufacturer’s instructions for buried
appli-
cations.
1210.6.1 Joints between different piping materials. 
Joints between different piping materials shall be made with 
transition fittings compatible with both materials and the fluid contained within the system. Transition fittings must 
be used i
n accordance with manufacturer’s instructions.
1210.6.1.1 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not 
less than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same water line.
1210.6.2 Prep
aration of pipe ends. 
Pipe shall be cut square, be reamed, and be free of burrs and obstructions. 
CPVC, PE, and PVC pipe shall be chamfered. Pipe ends shall have full
-
bore openings and shall not be undercut.
1210.6.3 Joint preparation and installation. 
Whe
re required by Sections 1210.6.4 through 1210.6.6, the prepa-
ration and installation of mechanical and thermoplastic
-
welded joints shall comply with Sections 1210.6.3.1 and 
1210.6.3.2.
1210.6.3.1 Mechanical joints. 
Mechanical joints shall be installed in ac
cordance with the manufacturer’s in-
structions.
1210.6.3.2 Thermoplastic
-
welded joints. 
Joint surfaces for thermoplastic
-
welded joints shall be cleaned by a 
procedure in accordance with the manufacturer’s instructions. Joints shall be welded in accordance w
ith the 
manufacturer’s instructions.
1210.6.4 CPVC plastic pipe. 
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded 
joints complying with Section 1203.3.
‡‡‡
1210.6.5 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints bet
ween cross
-
linked polyethylene plastic 
tubing and fittings shall comply with Section 1210.6.5.1. Mechanical joints shall comply with Section 1210.6.3.
1210.6.5.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
r
ings, 
the fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1210.6.6 Polyethylene plastic pipe and tubing for ground
-
source heat pump loop systems. 
Joints between 
polyethylene plastic pipe and tubing or fittings for 
ground
-
source heat pump loop systems shall be heat fusion 
joints complying with Section 1210.6.6.1, electrofusion joints complying with Section 1210.6.6.2, or stab
-
type 
insertion joints complying with Section 1210.6.6.3.
1210.6.6.1 Heat
-
fusion joints. 
Joints shall be of the socket
-
fusion, saddle
-
fusion or butt
-
fusion type, joined in 
accordance with ASTM D 2657. Joint surfaces shall be clean and free from moisture. Joint surfaces shall be 
heated to melt temperatures and joi
ned. The joint shall be undisturbed until cool. Fittings shall be manufactured 
in accordance with ASTM D 2683 or ASTM D 3261.
1210.6.6.2 Electrofusion joints. 
Joints shall be of the electrofusion type. Joint surfaces shall be clean and free 
from moisture, 
and scoured to expose virgin resin. Joint surfaces shall be heated to melt temperatures for the 
HYDRONIC PIPING
period of time specified by the manufacturer. The joint shall be undisturbed until cool. Fittings shall be manu-
factured in accordance with ASTM F 1055.
1210.6.6
.3 Stab
-
type insert fittings. 
Joint surfaces shall be clean and free from moisture. Pipe ends shall be 
chamfered and inserted into the fittings to full depth. Fittings shall be manufactured in accordance with ASTM 
F 1924.
1210.6.7 Polypropylene (PP) plasti
c. 
Joints between PP plastic pipe and fittings shall comply with Sections 
1210.6.7.1 and 1210.6.7.2.
1210.6.7.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylen
e fittings, electrofusion polypropylene fittings or by butt fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1210.6.7.2 Mechanical and compression 
sleeve joints. 
Mechanical and compression sleeve joints shall be 
installed in accordance with the manufacturer’s instructions.
1210.6.8 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyeth-
ylene tubing and fittin
gs shall comply with Sections 1210.6.8.1 and 1210.6.8.2. Mechanical joints shall comply 
with Section 1210.6.3.
1210.6.8.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, 
the fittings shall be installed wi
thout omitting the inserts and ferrules or O
-
rings.
1210.6.9 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded 
joints comply with Section 1203.3.
1210.7 Shutoff valves. 
Shutoff valves shall be installed in
ground
-
source loop piping systems in the locations indi-
cated in Sections 1210.7.1 through 1210.7.7.
1210.7.1 Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
Exception: 
Shutoff valves shall not be requi
red where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1210
.7.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of a central utility 
system.
1210.7.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1210.7.4 Pressure
-
reducing valves.
Shutoff valves shall be installed on both sides of a pressure
-
reducing valve.
1210.7.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a gr
ound
-
source loop system such as pumps, air 
separators, metering devices, and similar equipment.
1210.7.6 Expansion tanks. 
Shutoff valves shall be installed at connections to nondiaphragm
-
type expansion tanks.
1210.7.7 Reduced pressure. 
A pressure relief va
lve shall be installed on the low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system 
design. The valve shall be installed in accordance with Section 1006.
1210.8 
Installation. 
Piping, valves, fittings, and connections shall be installed in accordance with the 
conditions of approval.
1210.8.1 Protection of potable water. 
Where ground
-
source heat pump ground
-
loop systems have a connection 
to a potable water supply, t
he potable water system shall be protected from backflow in accordance with the 
New 
York City Plumbing Code
.
1210.8.2 Pipe penetrations. 
Openings for pipe penetrations in walls, floors and ceilings shall be larger than the 
penetrating pipe. Openings throug
h concrete or masonry building elements shall be sleeved. The annular space 
surrounding pipe penetrations shall be protected in accordance with the 
New York City Building Code
.
HYDRONIC PIPING
1210.8.3 Clearance from combustibles. 
A pipe in a ground
-
source heat pump pipin
g system having an exterior 
surface temperature exceeding 250°F (121.1°C) shall have a minimum clearance of 1 inch (25.4 mm) from com-
bustible materials.
1210.8.4 Contact with building material. 
A ground
-
source heat pump ground
-
loop piping system shall not 
be in 
direct contact with building materials that cause the piping or fitting material to degrade or corrode, or that interfere 
with the operation of the system.
1210.8.5 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains 
and stresses in the pipe. 
Provisions shall be made to protect piping from damage resulting from expansion, contraction and structural set-
tlement. Piping shall be installed so as to avoid structural stresses or strains within building components.
1210.8.6 F
lood hazard. 
Piping located in a flood hazard area shall be capable of resisting hydrostatic and hydro-
dynamic loads and stresses, including the effects of buoyancy, during the occurrence of flooding to the design flood 
elevation.
1210.8.7 Pipe support. 
Pip
e shall be supported in accordance with Section 305.
1210.8.8 Velocities. 
Ground
-
source heat pump ground
-
loop systems shall be designed so that the flow velocities 
do not exceed the maximum flow velocity recommended by the pipe and fittings 
manufacturer and shall be con-
trolled to reduce the possibility of water hammer.
1210.8.9 Labeling and marking. 
Ground
-
source heat pump ground
-
loop system piping shall be marked with tape, 
metal tags or other method where it enters a building indicating “GR
OUND
-
SOURCE HEAT PUMP LOOP SYS-
TEM.” The marking shall indicate any antifreeze used in the system by name and concentration.
1210.8.10 Chemical compatibility. 
Antifreeze and other materials used in the system shall be chemically compat-
ible with the 
pipe, tubing, fittings, and mechanical systems.
1210.9 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
1210.10 Tests. 
Before connection header trenches are backfilled, the assembled loop system shall be pr
essure tested 
with water at 100 psi (689.5 kPa) for 15 minutes, in which time there shall not be observed leaks. Flow and pressure 
loss testing shall be performed and the actual flow rates and pressure drops shall be compared to the calculated design 
value
s. If actual flow rate or pressure drop values differ from calculated design values by more than 10 percent, the 
cause shall be identified and corrective action taken.
1210.11 Embedded piping. 
Ground
-
source heat pump ground
-
loop piping to be embedded in co
ncrete shall be pres-
sure tested prior to pouring concrete. During pouring, the pipe shall be maintained at the proposed operating pressure. 
Embedded piping shall comply with Section 1209.
SECTION MC 1211
HIGH
-
PRESSURE STEAM AND
HIGH TEMPERATURE HOT WATER P
IPING SYSTEMS
1211.1 Scope.
The provisions of this section shall apply to high
-
pressure steam piping system, which is defined as a 
system operating at a steam pressure of more than 15 psi (103.4 kPa), and high temperature water intended for 
operation at pr
essures in excess of 160 psi (1103.2 kPa) and temperatures in excess of 250°F (121.1°C). For purposes 
of this section, loops, bends or offsets of the piping shall not be considered expansion joints.
1211.2 New systems.
For purposes of this section, the rep
lacement of existing steam piping systems, the installation 
of a new system in existing buildings, as well as installations in buildings hereafter constructed, shall be considered 
to be new high
-
pressure steam piping systems. The following requirements are
applicable:
1211.2.1 Design.
The design of new steam piping systems shall be conducted as follows:
1.
The system shall be designed by an engineer. An application and plans shall be filed and the approval of the 
department obtained. The plans and applicati
on shall contain, but not be limited to, the following information:
1.1.
Size and location of all steam piping.
HYDRONIC PIPING
1.2.
The operating pressures and temperatures.
1.3.
The location, type, specifications and details of all expansion joints.
1.4.
The design, siz
e, material and location of all anchors, guides and auxiliary steel, and the stresses thereon.
2.
Systems using utility street steam shall be designed for a pressure of 200 psig (1379 kPa) and 413°F (211.7°C) 
up to and including the steam pressure reducing
valve or valves which reduce the pressure of 90 psig (620.5 
kPa) or below. For steam pressures between 90 psig (620.5 kPa) and 16 psig (110.3 kPa), the system shall be 
designed for 125 psig (861.8 kPa).
3.
Steam distribution systems utilizing pressure red
ucing valves.
3.1.
Safety Shutoff Valves (SSO) to protect downstream piping from overpressure shall be allowed in lieu of 
a safety relief valve vented to the outdoors as required by Section 1006.6.
3.2.
SSO shall be designed to automatically close at or be
low the design pressure of the downstream piping 
system that is being protected, to provide positive shutoff against full upstream pressure. Manual reset 
shall be required to reopen the SSO.
3.3.
SSO shall be designed in accordance with the Steam Distribut
ion Utility System requirements of the 
utility company having jurisdiction and ASME B31.1.
4.
Bellows expansion joints shall not be utilized on high pressure steam piping.
Exception: 
Bellows expansion joints shall be permitted for final connection to equip
ment where readily 
accessible for inspection and service and within Mechanical Equipment Rooms.
1211.2.2 Installation.
The installation of new steam piping systems shall be conducted as follows:
1.
Installations, including any welding, shall be subject to 
special inspection.
2.
Welders shall be qualified for all required pipe sizes, wall thicknesses and positions in accordance with the 
ASME
Boiler and Pressure Vessel Code,
Section IX. Requalification is required every five years or sooner 
if the commissione
r has a specific reason to doubt a welder’s ability to make acceptable welds.
3.
Welder qualification testing shall be performed by an approved agency listed with the department, and the 
inspector witnessing the test shall be an authorized AWS Certified We
lding Inspector. If the testing is by 
radiography, the test specimen shall be evaluated by personnel having a minimum radiography qualification 
of Level II in accordance with the ASNT, Document No. SNT
-
TC
-
1A, Supplement A. A successful radio-
graphic test of
a production weld made within the 6 months prior to requalification may be considered as an 
acceptable requalification test.
4.
Copies of the certified welder qualification reports shall be maintained by the responsible welding agency 
and the company perf
orming the welding, and shall be made available upon request to the department.
5.
No reports from any welding inspection agency shall be accepted unless such agency has first requested and 
obtained approval from the department in accordance with rules of 
the department.
6.
Pipe welding shall conform to the following:
6.1.
All piping over 2 inches (
50.8
mm) shall be butt
-
welded. Piping 2 inches (50.8 mm) and under may be 
socket
-
welded or threaded, providing Schedule 80 piping is utilized.
6.2.
Threaded piping may continue to be used for existing construction in size of 6 inches (
152.4
mm) and 
under.
6.3.
Where welding is not feasible, the commissioner may allow an acceptable alternative.
7.
Radiographic examination, when required, shall be performed on butt
-
welds in accordance with ASME 
B31.1 based on the piping system design pressure and shall be as foll
ows:
Piping System Design Pressure
Percentage
90 psig (620.5 kPa) or below
Not RequiredB31.
1 and ASME B31.9, as applicable
. 
SECTION 
MC 
1202
MATERIAL
1202.1 Piping. 
Piping material, other than those contained within this section and conforming with the ASTM stand-
ards listed within this chapter, shall be of an approved type.
Exception: 
Embedded piping regulated by Section 1209, and ground
-
source heat pump loop systems regulated by 
Section 1210.
1202.2 Used existing materials. 
Reused pipe, fittings, valves or other materials shall be clean and free of foreign 
materials.
1202.3 Material rating. 
Materials shall be rated for the operating temperature and pressure of the hydronic system. 
Materials shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards. 
Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior 
of the pipe shall be protected from corrosion and d
egradation.
TABLE 1202.4
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene 
(ABS) plastic pipe
ASTM D 1527; ASTM F 2806
Chlorinated polyvinyl chloride 
(CPVC) plastic pipe
ASTM D 2846; ASTM F 441; 
ASTM F 442
Copper, 
brass, or copper
-
alloy 
pipe
ASTM B 42; ASTM B 43; 
ASTM B 302
Copper, brass, or copper
-
alloy 
tube (Type K, L or M)
ASTM B 75; ASTM B 88; 
ASTM B 135; ASTM B 251
HYDRONIC PIPING
Cross
-
linked 
polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe
ASTM F 1281; CSA
B137.10
Cross
-
linked polyethylene 
(PEX) tubing
ASTM F 876; ASTM F 877
Ductile iron pipe
AWWA C115/A21.15; AWWA 
C151/A21.51 
Polyethylene/aluminum/
polyet
hylene 
(PE
-
AL
-
PE) pressure 
pipe
ASTM F 1282; CSA B137.9
Polypropylene (PP) 
plastic pipe
ASTM F 2389
Polyvinyl chloride (PVC) 
plastic pipe
ASTM D 1785; ASTM D 2241
Raised temperature 
polyethylene (PE
-
RT)
ASTM F 2623; ASTM F 2769
Steel pipe
ASTM A 53/A 53M; ASTM A 
106
Steel tubing
ASTM A 254
1202.5 Pipe fittings. 
Hydronic pipe fittings shall conform to the respective pipe standards or to the standards listed in 
Table 1202.5.
TABLE 1202.5
HYDRONIC PIPE FITTINGS
MATERIAL
STANDARD (see Chapter 15)
Copper, brass, and copper 
alloys
ASME B16.15; ASME B16.18; ASME 
B16.22; 
ASME B16.24; 
ASME 
B16.26; 
ASME B16.51; ASTM F 
1974 
Ductile iron and gray iron
ANSI/AWWA C110/A21.10; 
AWWA C153/A21.53; ASTM A 
126; ASTM A 395; ASTM A 536; 
ASTM F 1476; ASTM F 1548
Malleable iron
ASME B16.3
PE
-
RT fittings
ASTM F 1807; ASTM F 2098; 
ASTM F 2159; ASTM F 2735; 
ASTM F 2769
PEX fittings
ASTM F 877; ASTM F 1807; ASTM 
F 2159
Plastic
ASTM D 2466; ASTM D 2467; 
ASTM F 438; ASTM F 439; ASTM 
F
877; ASTM F 2389; ASTM F 2735
HYDRONIC PIPING
Steel
ASME B16.5; ASME 
B16.9; ASME 
B16.11; ASME B16.28; ASTM A 
53/A 53M; ASTM A 106; ASTM A 
234; ASTM A 420; ASTM A 536; 
ASTM A 395; ASTM F 1476; ASTM 
F 1548
1202.6 Valves. 
Valves shall be constructed of materials that are compatible with the type of piping material and fluids 
in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration compensators. 
Flexible connectors, expansion and vibration 
control devices and fit
tings
, when used, shall protect the components of the hydronic system from damage caused by 
expansion, contraction, transverse movement, angular deflection and vibration,
shall be 
rated for the temperatures 
and pressures of the systems in which the devices
are installed, and shall be compatible with the fluid and all materials 
provided
.
SECTION 
MC 
1203
JOINTS AND CONNECTIONS
1203.1 Approval. 
Joints and connections
, other than those contained in Section 1203 and conforming to the ASTM 
standards listed in Sec
tion 1203,
shall be of an approved type. Joints and connections shall be tight for the pressure 
of the hydronic system.
1203.1.1 Joints between different piping materials. 
Joints between different piping materials shall be 
rated for 
the temperatures and pr
essures of the systems in which the devices are installed and shall be compatible with the 
fluid and all materials provided. 
1203.
1.2 Joints between dissimilar metallic piping materials.
Joints between dissimilar metallic piping mate-
rials shall be provide
d to protect against galvanic corrosion. Such joints shall be 
made with 
dielectric fittings 
conforming to ANSI B16.39 or ASTM F 492, as applicable, shall be rated for the temperatures and pressures of 
the systems in which the devices are installed and shal
l be compatible with the fluid and all materials provided
.
Exception:
Dielectric fittings shall not be required for joints between dissimilar metal piping used within heat 
transfer appliances or equipment when such joints are provided by the appliance or e
quipment manufacturer, 
and such appliance or equipment is connected with isolation valves that are accessible.
1203.2 Preparation of pipe ends. 
Pipe shall be cut square, reamed and chamfered, and shall be free of burrs and 
obstructions. Pipe ends shall hav
e full
-
bore openings and shall not be undercut.
1203.3 Joint preparation and installation. 
Where required by Sections 1203.4 through 1203.14, the preparation and 
installation of brazed, mechanical, soldered, 
solvent
-
cemented
, threaded and welded joints shall comply with Sections 
1203.3.1 through 1203.3.8.
1203.3.1 Brazed joints.
All joints 
shall
be brazed with a 
brazing procedure developed and qualified in accordance 
with the ASME
Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications) or in accord-
ance with 
AWS 
B2.2 Standard for Brazing Procedure and Performance Qualifica
tion
.
1203.3.2 Mechanical joints. 
Mechanical joints shall be installed in accordance with the manufacturer’s instruc-
tions.
1203.3.3 Soldered joints. 
Joint surfaces shall be cleaned. A flux conforming to ASTM B 813 shall be applied. The 
joint shall be solde
red with a solder conforming to ASTM B 32.
1203.3.4 Solvent
-
cemented joints. 
Joint surfaces shall be clean and free of moisture. 
A
primer
, compatible with 
both the piping material and the cement
shall be applied to pipe
-
joint surfaces
, in accordance with t
he manufac-
turer’s requirements
. Joints shall be made while the cement is wet. Solvent cement conforming to the following 
standards shall be applied to all joint surfaces:
1.
ASTM D 2235 for ABS joints.
2.
ASTM F 493 for CPVC joints.
HYDRONIC PIPING
3.
ASTM D 2564 for PVC 
joints.
1203.3.5 Threaded joints. 
Threads shall conform to ASME B1.20.1. Schedule 80 or heavier plastic pipe shall be 
threaded with dies specifically designed for plastic pipe. Thread lubricant, pipe
-
joint compound or tape shall be 
applied on the male threads only and shall be 
compatible
f
or application on the piping material
and fluid
.
1203.3.6 Welded joints.
All joints shall be welded with a welding procedure developed and qualified in accord-
ance with the 
ASME Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications
) or in 
accordance with AWS B2.1 Specifications for Welding Procedure and Performance Qualification.
1203.3.7 Grooved and shouldered mechanical joints. 
Grooved and shouldered mechanical joints shall conform 
to the requirements of ASTM F 1476 and shall be i
nstalled in accordance with the manufacturer’s
instructions.
1203.3.8 Mechanically formed tee fittings. 
Mechanically extracted outlets shall have a height not less than three 
times the thickness of the branch tube wall.
1203.3.8.1 Full flow assurance. 
Bran
ch tubes shall not restrict the flow in the run tube. A dimple/depth stop 
shall be formed in the branch tube to ensure that penetration into the outlet is of the correct depth. For inspection 
purposes, a second dimple shall be placed
1
/
4
inch (6.4 mm) above the first dimple. Dimples shall be aligned 
with the tube run.
1203.3.8.2 Brazed joints. 
Mechanically formed tee fittings shall be brazed in accordance with Section 1203.3.1.
1203.4 ABS plastic pipe. 
Joints between ABS plastic pipe or f
ittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.5 Brass pipe. 
Joints between brass pipe or fittings shall be brazed, mechanical, threaded or welded joints con-
forming to Section 1203.3.
1203.6 Brass tubing. 
Joints bet
ween brass tubing or fittings shall be brazed, mechanical or soldered joints conforming 
to Section 1203.3.
1203.7 Copper or copper
-
alloy pipe. 
Joints between copper or copper
-
alloy pipe or fittings shall be brazed, mechan-
ical, soldered, threaded or welded 
joints conforming to Section 1203.3.
1203.8 Copper or copper
-
alloy tubing. 
Joints between copper or copper
-
alloy tubing or fittings shall be brazed, 
mechanical or soldered joints conforming to Section 1203.3, flared joints conforming to Section 1203.8.1
or
push
-
fit 
joints conforming to Section 1203.8.2.
1203.8.1 Flared joints. 
Flared joints shall be made by a tool designed for that operation.
1203.8.2 Push
-
fit joints. 
Push
-
fit joints shall be installed in accordance with the manufacturer’s instructions.
120
3.9 CPVC plastic pipe.   
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.10 Reserved.
1203.11 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints between cross
-
linked polyethyle
ne plastic tubing 
and fittings shall conform to Sections 1203.11.1 and 1203.11.2. Mechanical joints shall conform to Section 1203.3.
1203.11.1 Compression
-
type fittings. 
Where
compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings 
shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.11.2 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not less 
than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same 
water line.
1203.12 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.13 Steel pipe. 
Joints between steel pipe or fittings shall be mechanical
, threaded or welded 
joints 
conforming to 
Section 1203.3.
1203.14 Steel tubing. 
Joints between steel tubing or fittings shall be mechanical or welded joints conforming to Sec-
tion 1203.3.
HYDRONIC PIPING
1203.15 Polypropylene (PP) plastic. 
Joints between PP plastic pipe and fittings shall comp
ly with Sections 1203.15.1 
and 1203.15.2.
1203.15.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylene fittings, electro
-
fusion polypropylene fittings or by butt
fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1203.15.2 Mechanical and compression sleeve joints. 
Mechanical and compression sleeve joints shal
l be installed 
in accordance with the manufacturer’s instructions.
1203.16 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyethylene 
tubing and fittings shall conform to Sections 1203.16.1 and 1203.16.2. Mechani
cal joints shall conform to Section 
1203.3.
1203.16.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.16.2 PE
-
RT
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 mm) 
of a transition from such metal pipe to PE
-
RT pipe.
1203.17 Polyethylene/aluminum/polyethylene (PE
-
AL
-
PE) pressure pipe. 
Joints between polyethylene/alumi-
num/po
lyethylene pressure pipe and fittings shall conform to Sections 1203.17.1 and 1203.17.2. Mechanical joints 
shall comply with Section 1203.3.
1203.17.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
f
ittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.17.2 PE
-
AL
-
PE
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 
mm) of a transition from such metal pipe to PE
-
AL
-
PE pipe.
1203.18 Cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe. 
Joints 
between cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene pressure pipe and fittings shall conform to 
Sections 1203.18.1 and 1203.18.2. Mecha
nical joints shall comply with Section 1203.3.
1203.18.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.18.2 PEX
-
AL
-
PEX
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches 
(457.2 mm) of a transition from such metal pipe to PEX
-
AL
-
PEX pipe.
SECTION 
MC 
1204
PIPE INSULATION
1204.1 Insulation characteristics. 
Pipe insulation installed in buildings shall conform to the requirements of the 
New 
York City
Energy Conservation Code
,
shall be tested in accordance with ASTM E 84 or UL 723, using the specimen 
preparation and mounting p
rocedures of ASTM E 2231; and shall have a maximum flame spread index of 25 and a 
smoke
-
developed index not exceeding 450. Insulation installed in an air plenum shall comply with Section 602.2.1.
1204.2 Required thickness. 
Hydronic piping shall be insulate
d to the thickness required by the 
New York City
Energy 
Conservation Code.
SECTION 
MC 
1205
VALVES
1205.1 Where required. 
Shutoff valves shall be installed in hydronic piping systems in the locations indicated in 
Sections 1205.1.1 through 1205.1.6.
1205.1.1
Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
HYDRONIC PIPING
Exception: 
Shutoff valves shall not be required where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat 
exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1205.1.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of central utility 
systems, and district
heating and cooling 
systems.
1205.1.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1205.1.4 Pressure
-
reducing valves. 
Shutoff valves shall be installed on both sides of a pressure
-
reduc
ing valve.
1205.1.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a hydronic system such as pumps, air separators, 
metering devices and si
milar equipment.
1205.1.6 Expansion tanks.
Lockable shutoff
valves shall be installed at connections to 
all
expansion tanks.
Valves shall be locked in the open position.
1205.2 Reduced pressure. 
A pressure relief valve shall be installed on the 
low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system design. 
The valve shall be installed in accordance with Section 1006.
SECTION 
MC 
1206
PIPING INSTALLATION
1
206.1 General. 
Piping, valves, fittings and connections shall be installed in accordance with the conditions of ap-
proval.
1206.2 System drain down. 
Hydronic piping systems shall be designed and installed to permit the system to be 
drained. Where the system
drains to the plumbing drainage system, the installation shall conform to the requirements 
of the 
New York City
Plumbing Code.
Exception: 
The buried portions of systems embedded underground.
1206.3 Protection of potable water. 
The potable water system sha
ll be protected from backflow in accordance with 
the 
New York City
Plumbing Code.
1206.4 Pipe penetrations. 
Openings for pipe penetrations in walls, floors or ceilings shall be larger than the penetrat-
ing pipe. Openings through concrete or masonry building
elements shall be sleeved. The annular space surrounding 
pipe penetrations shall be protected in accordance with the 
New York City
Building Code.
1206.5 Clearance to combustibles. 
A pipe in a hydronic piping system in which the exterior temperature exceed
s 
250°F (
121.1
°C) shall have a minimum clearance of 1 inch (25.4 mm) to combustible materials.
1206.6 Contact with building material. 
A hydronic piping system shall not be in direct contact with building mate-
rials that cause the piping material to degrade 
or corrode, or that interfere with the operation of the system.
1206.7 Water hammer. 
The flow velocity of the hydronic piping system shall be controlled to reduce the possibility 
of water hammer. Where a quick
-
closing valve creates water hammer, an 
enginee
red
water
-
hammer arrestor shall be 
installed. The arrestor shall be located within a range as specified by the manufacturer of the quick
-
closing valve.
1206.8 Steam piping pitch. 
Steam piping shall be installed to drain to the boiler or the steam trap. Ste
am systems 
shall not have drip pockets that reduce the capacity of the steam piping.
1206.9 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains and stresses in the pipe. 
Provisions shall be made to protect piping from damag
e resulting from expansion, contraction and structural settle-
ment. Piping shall be installed so as to avoid structural stresses or strains within building components.
1206.9.1 Flood hazard. 
Piping located in flood hazard areas 
shall comply with Appendix G
of 
the 
New York City 
Building Code
.
HYDRONIC PIPING
1206.10 Pipe support. 
Pipe shall be supported in accordance with Section 305.
Seismic supports shall be provided 
where required by the 
New York City Building Code.
1206.11 Condensation. 
Provisions shall be made to prevent the formation of condensation on the exterior of piping.
SECTION 
MC 
1207
TRANSFER FLUID
1207.1 Flash point. 
The
flash point of transfer fluid in a hydronic piping system shall be not less than 50°F (10°C) 
above the maximum system operating temperature.
1207.2 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
SECTION 
MC 
1208
TESTS
1208.1 General. 
Hydronic piping systems 
other than ground
-
source heat pump loop systems 
shall be tested hydro-
statically at one and one
half times the system design 
operating 
pressure, but not less than 100 psi (689 kPa). The 
duration of each 
test shall be not less than
2 hours. Ground
-
source heat pump loop systems shall be tested in accord-
ance with Section 1210.10.
SECTION 
MC 
1209
EMBEDDED PIPING
1209.1 Materials. 
Embedded piping
shall be plastic pipe or tubing
, in accordance with Section 1202
,
rated at 100 psi 
(689.5 kPa) at 180°F (82.2°C).
1209.2 Pressurizing during installation. 
Piping to be embedded in concrete shall be pressure tested prior to pouring 
concrete. During pouring, the pipe shall be maintained at the proposed operating pressure
.
1209.3 Embedded joints. 
Joints of pipe or tubing that are embedded in a portion of the building, such as concrete or 
plaster, shall be thermally
-
fused.
1209.4 Not embedded related piping. 
Joints of other piping in cavities or running exposed shall be joi
ned in accord-
ance with manufacturer’s instructions and related sections of this code.
1209.5 Thermal barrier required. 
Radiant floor heating systems shall be provided with a thermal barrier in accord-
ance with Sections 1209.5.1 through 1209.5.4.
Exception: 
Insulation shall not be required in engineered systems where it can be demonstrated that the insulation 
will decrease the efficiency or have a negative effect on the installation.
1209.5.1 Slab
-
on
-
grade installation. 
Radiant piping utilized in slab
-
on
-
grad
e applications shall be provided with 
insulating materials installed beneath the piping having a minimum R
-
value of 5.
1209.5.2 Suspended floor installation. 
In suspended floor applications, insulation shall be installed in the joist 
bay cavity serving the
heating space above and shall consist of materials having a minimum R
-
value of 11.
1209.5.3 Thermal break required. 
A thermal break shall be provided consisting of asphalt expansion joint mate-
rials or similar insulating materials at a point where a heated
slab meets a foundation wall or other conductive slab.
1209.5.4 Thermal barrier material marking. 
Insulating materials utilized in thermal barriers shall be installed 
such that the manufacturer’s R
-
value mark is readily observable upon inspection.
SECTION
MC 
1210
PLASTIC PIPE GROUND
-
SOURCE HEAT PUMP LOOP SYSTEMS
HYDRONIC PIPING
1210.1 Ground
-
source heat pump
-
loop water piping. 
Ground
-
source heat pump ground
-
loop piping and tubing 
material for water
-
based systems shall conform to the standards cited in this section.
1210.2
Used materials. 
Reused pipe, fittings, valves, and other materials shall not be permitted in ground
-
source heat 
pump loop systems.
1210.3 Material rating. 
Pipe and tubing shall be rated for the operating temperature and pressure of the ground
-
source heat 
pump loop system. Fittings shall be suitable for the pressure applications and recommended by the man-
ufacturer for installation with the pipe and tubing material installed. Where used underground, materials shall be suit-
able for burial.
1210.4 Piping and t
ubing materials standards. 
Ground
-
source heat pump ground
-
loop pipe and tubing shall con-
form to the standards listed in Table 1210.4.
TABLE 1210.4
GROUND
-
SOURCE LOOP PIPE
MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl chloride 
(CPVC)
ASTM D 
2846; ASTM F 
441; ASTM F 442
Cross
-
linked polyethylene (PEX)
ASTM F 876; ASTM F 877; 
CSA B137.5
Polyethylene/aluminum/polyethylen
e (PE
-
AL
-
PE) pressure pipe
ASTM F 1282; CSA B137.9
High
-
density polyethylene (HDPE)
ASTM D 2737; ASTM D 
3035; ASTM F 
714; AWWA 
C901; CSA B137.1; CSA 
C448; NSF 358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl chloride (PVC)
ASTM D 1785; ASTM D 
2241
Raised temperature polyethylene 
(PE
-
RT)
ASTM F 2623
1210.5 Fittings. 
Ground
-
source heat pump pipe fittings shall conform to the standards listed in Table 1210.5 and, if 
installed underground, shall be suitable for burial. 
TABLE 1210.5
GROUND
-
SOURCE LOOP PIPE FITTINGS
PIPE MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl 
chloride (CPVC)
ASTM D 2846; ASTM F 437; ASTM F 
438; ASTM F 439; CSA B137.6
Cross
-
linked 
polyethylene (PEX)
ASTM F 877; ASTM F 1807; ASTM F 
1960; ASTM F 2080; ASTM F 2159; 
ASTM F 2434; CSA B137.5
Polyethylene/aluminum/
polyethylene (PE
-
AL
-
PE)
ASTM F 1282; ASTM F 2434; CSA 
B137.9
HYDRONIC PIPING
High Density 
Polyethylene (HDPE)
ASTM D 2683; ASTM D 3261; ASTM 
F 1055; CSA B137.1; CSA C448; NSF 
358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl 
chloride 
(PVC)
ASTM D 2464; ASTM D 2466; ASTM 
D 2467; CSA B137.2; CSA B137.3
Raised temperature 
polyethylene (PE
-
RT)
ASTM D 3261; ASTM F 1807; ASTM 
F 2159; CSA B137.1
1210.6 Joints. 
Joints and connections, 
other than those covered by Section 1210 and co
nforming to the ASTM stand-
ards listed therein,
shall be of an approved type. Joints and connections shall be tight for the pressure of the ground
-
source loop system. Joints used underground shall be in accordance with manufacturer’s instructions for buried
appli-
cations.
1210.6.1 Joints between different piping materials. 
Joints between different piping materials shall be made with 
transition fittings compatible with both materials and the fluid contained within the system. Transition fittings must 
be used i
n accordance with manufacturer’s instructions.
1210.6.1.1 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not 
less than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same water line.
1210.6.2 Prep
aration of pipe ends. 
Pipe shall be cut square, be reamed, and be free of burrs and obstructions. 
CPVC, PE, and PVC pipe shall be chamfered. Pipe ends shall have full
-
bore openings and shall not be undercut.
1210.6.3 Joint preparation and installation. 
Whe
re required by Sections 1210.6.4 through 1210.6.6, the prepa-
ration and installation of mechanical and thermoplastic
-
welded joints shall comply with Sections 1210.6.3.1 and 
1210.6.3.2.
1210.6.3.1 Mechanical joints. 
Mechanical joints shall be installed in ac
cordance with the manufacturer’s in-
structions.
1210.6.3.2 Thermoplastic
-
welded joints. 
Joint surfaces for thermoplastic
-
welded joints shall be cleaned by a 
procedure in accordance with the manufacturer’s instructions. Joints shall be welded in accordance w
ith the 
manufacturer’s instructions.
1210.6.4 CPVC plastic pipe. 
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded 
joints complying with Section 1203.3.
‡‡‡
1210.6.5 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints bet
ween cross
-
linked polyethylene plastic 
tubing and fittings shall comply with Section 1210.6.5.1. Mechanical joints shall comply with Section 1210.6.3.
1210.6.5.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
r
ings, 
the fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1210.6.6 Polyethylene plastic pipe and tubing for ground
-
source heat pump loop systems. 
Joints between 
polyethylene plastic pipe and tubing or fittings for 
ground
-
source heat pump loop systems shall be heat fusion 
joints complying with Section 1210.6.6.1, electrofusion joints complying with Section 1210.6.6.2, or stab
-
type 
insertion joints complying with Section 1210.6.6.3.
1210.6.6.1 Heat
-
fusion joints. 
Joints shall be of the socket
-
fusion, saddle
-
fusion or butt
-
fusion type, joined in 
accordance with ASTM D 2657. Joint surfaces shall be clean and free from moisture. Joint surfaces shall be 
heated to melt temperatures and joi
ned. The joint shall be undisturbed until cool. Fittings shall be manufactured 
in accordance with ASTM D 2683 or ASTM D 3261.
1210.6.6.2 Electrofusion joints. 
Joints shall be of the electrofusion type. Joint surfaces shall be clean and free 
from moisture, 
and scoured to expose virgin resin. Joint surfaces shall be heated to melt temperatures for the 
HYDRONIC PIPING
period of time specified by the manufacturer. The joint shall be undisturbed until cool. Fittings shall be manu-
factured in accordance with ASTM F 1055.
1210.6.6
.3 Stab
-
type insert fittings. 
Joint surfaces shall be clean and free from moisture. Pipe ends shall be 
chamfered and inserted into the fittings to full depth. Fittings shall be manufactured in accordance with ASTM 
F 1924.
1210.6.7 Polypropylene (PP) plasti
c. 
Joints between PP plastic pipe and fittings shall comply with Sections 
1210.6.7.1 and 1210.6.7.2.
1210.6.7.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylen
e fittings, electrofusion polypropylene fittings or by butt fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1210.6.7.2 Mechanical and compression 
sleeve joints. 
Mechanical and compression sleeve joints shall be 
installed in accordance with the manufacturer’s instructions.
1210.6.8 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyeth-
ylene tubing and fittin
gs shall comply with Sections 1210.6.8.1 and 1210.6.8.2. Mechanical joints shall comply 
with Section 1210.6.3.
1210.6.8.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, 
the fittings shall be installed wi
thout omitting the inserts and ferrules or O
-
rings.
1210.6.9 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded 
joints comply with Section 1203.3.
1210.7 Shutoff valves. 
Shutoff valves shall be installed in
ground
-
source loop piping systems in the locations indi-
cated in Sections 1210.7.1 through 1210.7.7.
1210.7.1 Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
Exception: 
Shutoff valves shall not be requi
red where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1210
.7.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of a central utility 
system.
1210.7.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1210.7.4 Pressure
-
reducing valves.
Shutoff valves shall be installed on both sides of a pressure
-
reducing valve.
1210.7.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a gr
ound
-
source loop system such as pumps, air 
separators, metering devices, and similar equipment.
1210.7.6 Expansion tanks. 
Shutoff valves shall be installed at connections to nondiaphragm
-
type expansion tanks.
1210.7.7 Reduced pressure. 
A pressure relief va
lve shall be installed on the low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system 
design. The valve shall be installed in accordance with Section 1006.
1210.8 
Installation. 
Piping, valves, fittings, and connections shall be installed in accordance with the 
conditions of approval.
1210.8.1 Protection of potable water. 
Where ground
-
source heat pump ground
-
loop systems have a connection 
to a potable water supply, t
he potable water system shall be protected from backflow in accordance with the 
New 
York City Plumbing Code
.
1210.8.2 Pipe penetrations. 
Openings for pipe penetrations in walls, floors and ceilings shall be larger than the 
penetrating pipe. Openings throug
h concrete or masonry building elements shall be sleeved. The annular space 
surrounding pipe penetrations shall be protected in accordance with the 
New York City Building Code
.
HYDRONIC PIPING
1210.8.3 Clearance from combustibles. 
A pipe in a ground
-
source heat pump pipin
g system having an exterior 
surface temperature exceeding 250°F (121.1°C) shall have a minimum clearance of 1 inch (25.4 mm) from com-
bustible materials.
1210.8.4 Contact with building material. 
A ground
-
source heat pump ground
-
loop piping system shall not 
be in 
direct contact with building materials that cause the piping or fitting material to degrade or corrode, or that interfere 
with the operation of the system.
1210.8.5 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains 
and stresses in the pipe. 
Provisions shall be made to protect piping from damage resulting from expansion, contraction and structural set-
tlement. Piping shall be installed so as to avoid structural stresses or strains within building components.
1210.8.6 F
lood hazard. 
Piping located in a flood hazard area shall be capable of resisting hydrostatic and hydro-
dynamic loads and stresses, including the effects of buoyancy, during the occurrence of flooding to the design flood 
elevation.
1210.8.7 Pipe support. 
Pip
e shall be supported in accordance with Section 305.
1210.8.8 Velocities. 
Ground
-
source heat pump ground
-
loop systems shall be designed so that the flow velocities 
do not exceed the maximum flow velocity recommended by the pipe and fittings 
manufacturer and shall be con-
trolled to reduce the possibility of water hammer.
1210.8.9 Labeling and marking. 
Ground
-
source heat pump ground
-
loop system piping shall be marked with tape, 
metal tags or other method where it enters a building indicating “GR
OUND
-
SOURCE HEAT PUMP LOOP SYS-
TEM.” The marking shall indicate any antifreeze used in the system by name and concentration.
1210.8.10 Chemical compatibility. 
Antifreeze and other materials used in the system shall be chemically compat-
ible with the 
pipe, tubing, fittings, and mechanical systems.
1210.9 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
1210.10 Tests. 
Before connection header trenches are backfilled, the assembled loop system shall be pr
essure tested 
with water at 100 psi (689.5 kPa) for 15 minutes, in which time there shall not be observed leaks. Flow and pressure 
loss testing shall be performed and the actual flow rates and pressure drops shall be compared to the calculated design 
value
s. If actual flow rate or pressure drop values differ from calculated design values by more than 10 percent, the 
cause shall be identified and corrective action taken.
1210.11 Embedded piping. 
Ground
-
source heat pump ground
-
loop piping to be embedded in co
ncrete shall be pres-
sure tested prior to pouring concrete. During pouring, the pipe shall be maintained at the proposed operating pressure. 
Embedded piping shall comply with Section 1209.
SECTION MC 1211
HIGH
-
PRESSURE STEAM AND
HIGH TEMPERATURE HOT WATER P
IPING SYSTEMS
1211.1 Scope.
The provisions of this section shall apply to high
-
pressure steam piping system, which is defined as a 
system operating at a steam pressure of more than 15 psi (103.4 kPa), and high temperature water intended for 
operation at pr
essures in excess of 160 psi (1103.2 kPa) and temperatures in excess of 250°F (121.1°C). For purposes 
of this section, loops, bends or offsets of the piping shall not be considered expansion joints.
1211.2 New systems.
For purposes of this section, the rep
lacement of existing steam piping systems, the installation 
of a new system in existing buildings, as well as installations in buildings hereafter constructed, shall be considered 
to be new high
-
pressure steam piping systems. The following requirements are
applicable:
1211.2.1 Design.
The design of new steam piping systems shall be conducted as follows:
1.
The system shall be designed by an engineer. An application and plans shall be filed and the approval of the 
department obtained. The plans and applicati
on shall contain, but not be limited to, the following information:
1.1.
Size and location of all steam piping.
HYDRONIC PIPING
1.2.
The operating pressures and temperatures.
1.3.
The location, type, specifications and details of all expansion joints.
1.4.
The design, siz
e, material and location of all anchors, guides and auxiliary steel, and the stresses thereon.
2.
Systems using utility street steam shall be designed for a pressure of 200 psig (1379 kPa) and 413°F (211.7°C) 
up to and including the steam pressure reducing
valve or valves which reduce the pressure of 90 psig (620.5 
kPa) or below. For steam pressures between 90 psig (620.5 kPa) and 16 psig (110.3 kPa), the system shall be 
designed for 125 psig (861.8 kPa).
3.
Steam distribution systems utilizing pressure red
ucing valves.
3.1.
Safety Shutoff Valves (SSO) to protect downstream piping from overpressure shall be allowed in lieu of 
a safety relief valve vented to the outdoors as required by Section 1006.6.
3.2.
SSO shall be designed to automatically close at or be
low the design pressure of the downstream piping 
system that is being protected, to provide positive shutoff against full upstream pressure. Manual reset 
shall be required to reopen the SSO.
3.3.
SSO shall be designed in accordance with the Steam Distribut
ion Utility System requirements of the 
utility company having jurisdiction and ASME B31.1.
4.
Bellows expansion joints shall not be utilized on high pressure steam piping.
Exception: 
Bellows expansion joints shall be permitted for final connection to equip
ment where readily 
accessible for inspection and service and within Mechanical Equipment Rooms.
1211.2.2 Installation.
The installation of new steam piping systems shall be conducted as follows:
1.
Installations, including any welding, shall be subject to 
special inspection.
2.
Welders shall be qualified for all required pipe sizes, wall thicknesses and positions in accordance with the 
ASME
Boiler and Pressure Vessel Code,
Section IX. Requalification is required every five years or sooner 
if the commissione
r has a specific reason to doubt a welder’s ability to make acceptable welds.
3.
Welder qualification testing shall be performed by an approved agency listed with the department, and the 
inspector witnessing the test shall be an authorized AWS Certified We
lding Inspector. If the testing is by 
radiography, the test specimen shall be evaluated by personnel having a minimum radiography qualification 
of Level II in accordance with the ASNT, Document No. SNT
-
TC
-
1A, Supplement A. A successful radio-
graphic test of
a production weld made within the 6 months prior to requalification may be considered as an 
acceptable requalification test.
4.
Copies of the certified welder qualification reports shall be maintained by the responsible welding agency 
and the company perf
orming the welding, and shall be made available upon request to the department.
5.
No reports from any welding inspection agency shall be accepted unless such agency has first requested and 
obtained approval from the department in accordance with rules of 
the department.
6.
Pipe welding shall conform to the following:
6.1.
All piping over 2 inches (
50.8
mm) shall be butt
-
welded. Piping 2 inches (50.8 mm) and under may be 
socket
-
welded or threaded, providing Schedule 80 piping is utilized.
6.2.
Threaded piping may continue to be used for existing construction in size of 6 inches (
152.4
mm) and 
under.
6.3.
Where welding is not feasible, the commissioner may allow an acceptable alternative.
7.
Radiographic examination, when required, shall be performed on butt
-
welds in accordance with ASME 
B31.1 based on the piping system design pressure and shall be as foll
ows:
Piping System Design Pressure
Percentage
90 psig (620.5 kPa) or below
Not Required
HYDRONIC PIPING
91 psig (627.4 kPa) to
150 psig (1034.2 kPa)
10 at Random
Over 150 psig (1034.2 kPa)
100
However, if, in the opinion of the engineer responsible for special inspection, radiographic examination is not 
required for piping at pressure between 90 psig (620.5 kPa) and 150 psig (1034.2 kPa), the engineer shall so specify 
in writing, and the final r
eport on the installation may omit the foregoing, and be predicated on all of the other 
requirements noted in this section, and a hydrostatic test.
1211.2.3 Testing.
Hydrostatic testing shall be conducted on the completed installation at 150 percent of the
design 
pressure for all piping pressure. Where the changes in an existing steam system involve less than 30 percent of 
the piping in the system, the testing may be in accordance with ASME B31.1.
1211.2.4 Relocation.
The commissioner, where deemed necessar
y, shall require the replacement or relocation of 
any expansion joints, guides or anchors. The commissioner shall cause the expansion joints in potentially hazard-
ous locations, such as those that are located adjacent to tenant occupied spaces, to be reloca
ted, unless means exist 
or are provided for eliminating the hazard.
1211.3 Existing systems.
Existing steam piping systems shall be in accordance with Sections 1211.3.1 through 
1211.3.2. Upon the completion of a new high
-
pressure steam piping system and de
partment approval of same, the 
rules relating to maintenance requirements and the keeping of records for existing high
-
pressure steam piping sys-
tems shall apply.
1211.3.1 Maintenance inspections.
Expansion joints, anchorage and guides shall be inspected as
follows:
1.
Expansion joints shall be visually inspected monthly.
2.
The anchorage and guides shall be visually inspected annually. Exposure of the structural attachments to the 
buildings of the anchorages or guides shall not be required.
3.
A record of s
uch inspections shall be kept by the person in charge of the mechanical equipment of the building 
or other qualified person designated by the owner and acceptable to the commissioner. The records shall be 
available at the premises and subject to inspection
by the commissioner.
1211.3.2 Work approval.
No joint, anchorage or guides shall be repaired, replaced or relocated without a work 
permit issued by the department. The application for the permit shall contain all pertinent information and shall 
be filed by an engineer knowledgeable as to high
-
pressur
e steam piping systems. The engineer shall be responsible 
for the special inspection of the proposed work in accordance with the approved application. This provision shall 
not apply to the repacking of a slip or ball joint; however, records of such repacki
ng shall be kept in the inspection 
records as provided in Section 1211.3.1, Item 3. When, in the opinion of the engineer, the requirement for prior 
department approval would create an imminent health or safety hazard, the engineer may permit the work to 
pr
oceed without prior approval. In such cases, the engineer shall, prior to the repair, replacement or relocation, 
notify by telephone the borough commissioner of the borough in which the building is located; and, if the emer-
gency occurs at other than normal
working hours, he or she shall notify the department in a manner prescribed by 
the commissioner. This shall be followed by the filing of the application for department approval as specified in 
Section 28
-
105.4.1 of the 
Administrative Code
.
‡‡‡ Chapter 12 was amended by 
Local Law 
77 
of 2023
. This law has an effective
date of June 10, 2023.
CHAPTER 12
HYDRONIC PIPING 
SECTION MC 1201
GENERAL
1201.1 Scope. 
The provisions of this chapter shall govern the construction, installation, alteration and repair of hy-
dronic piping systems. This chapter shall apply to hydronic piping systems that are part of heating, ventilation and air
-
conditioning systems. Such piping systems shall include steam, hot water, chilled water, condenser water, cooling 
coil condensate drain, 
steam condensate and ground
-
source heat pump loop systems. Potable cold and hot water dis-
tribution systems shall be installed in accordance with the 
New York City
Plumbing Code
. 
1201.2 Sizing. 
Piping and piping system components for hydronic systems shall be sized for the 
design requirements
of the system.
1201.3 Standards. 
As an alternative to the provisions of Sections 1202 and 1203, piping shall be designed, installed, 
inspected and tested in accordance with ASME B31.
1 and ASME B31.9, as applicable
. 
SECTION 
MC 
1202
MATERIAL
1202.1 Piping. 
Piping material, other than those contained within this section and conforming with the ASTM stand-
ards listed within this chapter, shall be of an approved type.
Exception: 
Embedded piping regulated by Section 1209, and ground
-
source heat pump loop systems regulated by 
Section 1210.
1202.2 Used existing materials. 
Reused pipe, fittings, valves or other materials shall be clean and free of foreign 
materials.
1202.3 Material rating. 
Materials shall be rated for the operating temperature and pressure of the hydronic system. 
Materials shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards. 
Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior 
of the pipe shall be protected from corrosion and d
egradation.
TABLE 1202.4
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene 
(ABS) plastic pipe
ASTM D 1527; ASTM F 2806
Chlorinated polyvinyl chloride 
(CPVC) plastic pipe
ASTM D 2846; ASTM F 441; 
ASTM F 442
Copper, 
brass, or copper
-
alloy 
pipe
ASTM B 42; ASTM B 43; 
ASTM B 302
Copper, brass, or copper
-
alloy 
tube (Type K, L or M)
ASTM B 75; ASTM B 88; 
ASTM B 135; ASTM B 251
HYDRONIC PIPING
Cross
-
linked 
polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe
ASTM F 1281; CSA
B137.10
Cross
-
linked polyethylene 
(PEX) tubing
ASTM F 876; ASTM F 877
Ductile iron pipe
AWWA C115/A21.15; AWWA 
C151/A21.51 
Polyethylene/aluminum/
polyet
hylene 
(PE
-
AL
-
PE) pressure 
pipe
ASTM F 1282; CSA B137.9
Polypropylene (PP) 
plastic pipe
ASTM F 2389
Polyvinyl chloride (PVC) 
plastic pipe
ASTM D 1785; ASTM D 2241
Raised temperature 
polyethylene (PE
-
RT)
ASTM F 2623; ASTM F 2769
Steel pipe
ASTM A 53/A 53M; ASTM A 
106
Steel tubing
ASTM A 254
1202.5 Pipe fittings. 
Hydronic pipe fittings shall conform to the respective pipe standards or to the standards listed in 
Table 1202.5.
TABLE 1202.5
HYDRONIC PIPE FITTINGS
MATERIAL
STANDARD (see Chapter 15)
Copper, brass, and copper 
alloys
ASME B16.15; ASME B16.18; ASME 
B16.22; 
ASME B16.24; 
ASME 
B16.26; 
ASME B16.51; ASTM F 
1974 
Ductile iron and gray iron
ANSI/AWWA C110/A21.10; 
AWWA C153/A21.53; ASTM A 
126; ASTM A 395; ASTM A 536; 
ASTM F 1476; ASTM F 1548
Malleable iron
ASME B16.3
PE
-
RT fittings
ASTM F 1807; ASTM F 2098; 
ASTM F 2159; ASTM F 2735; 
ASTM F 2769
PEX fittings
ASTM F 877; ASTM F 1807; ASTM 
F 2159
Plastic
ASTM D 2466; ASTM D 2467; 
ASTM F 438; ASTM F 439; ASTM 
F
877; ASTM F 2389; ASTM F 2735
HYDRONIC PIPING
Steel
ASME B16.5; ASME 
B16.9; ASME 
B16.11; ASME B16.28; ASTM A 
53/A 53M; ASTM A 106; ASTM A 
234; ASTM A 420; ASTM A 536; 
ASTM A 395; ASTM F 1476; ASTM 
F 1548
1202.6 Valves. 
Valves shall be constructed of materials that are compatible with the type of piping material and fluids 
in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration compensators. 
Flexible connectors, expansion and vibration 
control devices and fit
tings
, when used, shall protect the components of the hydronic system from damage caused by 
expansion, contraction, transverse movement, angular deflection and vibration,
shall be 
rated for the temperatures 
and pressures of the systems in which the devices
are installed, and shall be compatible with the fluid and all materials 
provided
.
SECTION 
MC 
1203
JOINTS AND CONNECTIONS
1203.1 Approval. 
Joints and connections
, other than those contained in Section 1203 and conforming to the ASTM 
standards listed in Sec
tion 1203,
shall be of an approved type. Joints and connections shall be tight for the pressure 
of the hydronic system.
1203.1.1 Joints between different piping materials. 
Joints between different piping materials shall be 
rated for 
the temperatures and pr
essures of the systems in which the devices are installed and shall be compatible with the 
fluid and all materials provided. 
1203.
1.2 Joints between dissimilar metallic piping materials.
Joints between dissimilar metallic piping mate-
rials shall be provide
d to protect against galvanic corrosion. Such joints shall be 
made with 
dielectric fittings 
conforming to ANSI B16.39 or ASTM F 492, as applicable, shall be rated for the temperatures and pressures of 
the systems in which the devices are installed and shal
l be compatible with the fluid and all materials provided
.
Exception:
Dielectric fittings shall not be required for joints between dissimilar metal piping used within heat 
transfer appliances or equipment when such joints are provided by the appliance or e
quipment manufacturer, 
and such appliance or equipment is connected with isolation valves that are accessible.
1203.2 Preparation of pipe ends. 
Pipe shall be cut square, reamed and chamfered, and shall be free of burrs and 
obstructions. Pipe ends shall hav
e full
-
bore openings and shall not be undercut.
1203.3 Joint preparation and installation. 
Where required by Sections 1203.4 through 1203.14, the preparation and 
installation of brazed, mechanical, soldered, 
solvent
-
cemented
, threaded and welded joints shall comply with Sections 
1203.3.1 through 1203.3.8.
1203.3.1 Brazed joints.
All joints 
shall
be brazed with a 
brazing procedure developed and qualified in accordance 
with the ASME
Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications) or in accord-
ance with 
AWS 
B2.2 Standard for Brazing Procedure and Performance Qualifica
tion
.
1203.3.2 Mechanical joints. 
Mechanical joints shall be installed in accordance with the manufacturer’s instruc-
tions.
1203.3.3 Soldered joints. 
Joint surfaces shall be cleaned. A flux conforming to ASTM B 813 shall be applied. The 
joint shall be solde
red with a solder conforming to ASTM B 32.
1203.3.4 Solvent
-
cemented joints. 
Joint surfaces shall be clean and free of moisture. 
A
primer
, compatible with 
both the piping material and the cement
shall be applied to pipe
-
joint surfaces
, in accordance with t
he manufac-
turer’s requirements
. Joints shall be made while the cement is wet. Solvent cement conforming to the following 
standards shall be applied to all joint surfaces:
1.
ASTM D 2235 for ABS joints.
2.
ASTM F 493 for CPVC joints.
HYDRONIC PIPING
3.
ASTM D 2564 for PVC 
joints.
1203.3.5 Threaded joints. 
Threads shall conform to ASME B1.20.1. Schedule 80 or heavier plastic pipe shall be 
threaded with dies specifically designed for plastic pipe. Thread lubricant, pipe
-
joint compound or tape shall be 
applied on the male threads only and shall be 
compatible
f
or application on the piping material
and fluid
.
1203.3.6 Welded joints.
All joints shall be welded with a welding procedure developed and qualified in accord-
ance with the 
ASME Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications
) or in 
accordance with AWS B2.1 Specifications for Welding Procedure and Performance Qualification.
1203.3.7 Grooved and shouldered mechanical joints. 
Grooved and shouldered mechanical joints shall conform 
to the requirements of ASTM F 1476 and shall be i
nstalled in accordance with the manufacturer’s
instructions.
1203.3.8 Mechanically formed tee fittings. 
Mechanically extracted outlets shall have a height not less than three 
times the thickness of the branch tube wall.
1203.3.8.1 Full flow assurance. 
Bran
ch tubes shall not restrict the flow in the run tube. A dimple/depth stop 
shall be formed in the branch tube to ensure that penetration into the outlet is of the correct depth. For inspection 
purposes, a second dimple shall be placed
1
/
4
inch (6.4 mm) above the first dimple. Dimples shall be aligned 
with the tube run.
1203.3.8.2 Brazed joints. 
Mechanically formed tee fittings shall be brazed in accordance with Section 1203.3.1.
1203.4 ABS plastic pipe. 
Joints between ABS plastic pipe or f
ittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.5 Brass pipe. 
Joints between brass pipe or fittings shall be brazed, mechanical, threaded or welded joints con-
forming to Section 1203.3.
1203.6 Brass tubing. 
Joints bet
ween brass tubing or fittings shall be brazed, mechanical or soldered joints conforming 
to Section 1203.3.
1203.7 Copper or copper
-
alloy pipe. 
Joints between copper or copper
-
alloy pipe or fittings shall be brazed, mechan-
ical, soldered, threaded or welded 
joints conforming to Section 1203.3.
1203.8 Copper or copper
-
alloy tubing. 
Joints between copper or copper
-
alloy tubing or fittings shall be brazed, 
mechanical or soldered joints conforming to Section 1203.3, flared joints conforming to Section 1203.8.1
or
push
-
fit 
joints conforming to Section 1203.8.2.
1203.8.1 Flared joints. 
Flared joints shall be made by a tool designed for that operation.
1203.8.2 Push
-
fit joints. 
Push
-
fit joints shall be installed in accordance with the manufacturer’s instructions.
120
3.9 CPVC plastic pipe.   
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.10 Reserved.
1203.11 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints between cross
-
linked polyethyle
ne plastic tubing 
and fittings shall conform to Sections 1203.11.1 and 1203.11.2. Mechanical joints shall conform to Section 1203.3.
1203.11.1 Compression
-
type fittings. 
Where
compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings 
shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.11.2 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not less 
than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same 
water line.
1203.12 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.13 Steel pipe. 
Joints between steel pipe or fittings shall be mechanical
, threaded or welded 
joints 
conforming to 
Section 1203.3.
1203.14 Steel tubing. 
Joints between steel tubing or fittings shall be mechanical or welded joints conforming to Sec-
tion 1203.3.
HYDRONIC PIPING
1203.15 Polypropylene (PP) plastic. 
Joints between PP plastic pipe and fittings shall comp
ly with Sections 1203.15.1 
and 1203.15.2.
1203.15.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylene fittings, electro
-
fusion polypropylene fittings or by butt
fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1203.15.2 Mechanical and compression sleeve joints. 
Mechanical and compression sleeve joints shal
l be installed 
in accordance with the manufacturer’s instructions.
1203.16 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyethylene 
tubing and fittings shall conform to Sections 1203.16.1 and 1203.16.2. Mechani
cal joints shall conform to Section 
1203.3.
1203.16.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.16.2 PE
-
RT
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 mm) 
of a transition from such metal pipe to PE
-
RT pipe.
1203.17 Polyethylene/aluminum/polyethylene (PE
-
AL
-
PE) pressure pipe. 
Joints between polyethylene/alumi-
num/po
lyethylene pressure pipe and fittings shall conform to Sections 1203.17.1 and 1203.17.2. Mechanical joints 
shall comply with Section 1203.3.
1203.17.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
f
ittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.17.2 PE
-
AL
-
PE
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 
mm) of a transition from such metal pipe to PE
-
AL
-
PE pipe.
1203.18 Cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe. 
Joints 
between cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene pressure pipe and fittings shall conform to 
Sections 1203.18.1 and 1203.18.2. Mecha
nical joints shall comply with Section 1203.3.
1203.18.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.18.2 PEX
-
AL
-
PEX
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches 
(457.2 mm) of a transition from such metal pipe to PEX
-
AL
-
PEX pipe.
SECTION 
MC 
1204
PIPE INSULATION
1204.1 Insulation characteristics. 
Pipe insulation installed in buildings shall conform to the requirements of the 
New 
York City
Energy Conservation Code
,
shall be tested in accordance with ASTM E 84 or UL 723, using the specimen 
preparation and mounting p
rocedures of ASTM E 2231; and shall have a maximum flame spread index of 25 and a 
smoke
-
developed index not exceeding 450. Insulation installed in an air plenum shall comply with Section 602.2.1.
1204.2 Required thickness. 
Hydronic piping shall be insulate
d to the thickness required by the 
New York City
Energy 
Conservation Code.
SECTION 
MC 
1205
VALVES
1205.1 Where required. 
Shutoff valves shall be installed in hydronic piping systems in the locations indicated in 
Sections 1205.1.1 through 1205.1.6.
1205.1.1
Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
HYDRONIC PIPING
Exception: 
Shutoff valves shall not be required where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat 
exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1205.1.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of central utility 
systems, and district
heating and cooling 
systems.
1205.1.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1205.1.4 Pressure
-
reducing valves. 
Shutoff valves shall be installed on both sides of a pressure
-
reduc
ing valve.
1205.1.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a hydronic system such as pumps, air separators, 
metering devices and si
milar equipment.
1205.1.6 Expansion tanks.
Lockable shutoff
valves shall be installed at connections to 
all
expansion tanks.
Valves shall be locked in the open position.
1205.2 Reduced pressure. 
A pressure relief valve shall be installed on the 
low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system design. 
The valve shall be installed in accordance with Section 1006.
SECTION 
MC 
1206
PIPING INSTALLATION
1
206.1 General. 
Piping, valves, fittings and connections shall be installed in accordance with the conditions of ap-
proval.
1206.2 System drain down. 
Hydronic piping systems shall be designed and installed to permit the system to be 
drained. Where the system
drains to the plumbing drainage system, the installation shall conform to the requirements 
of the 
New York City
Plumbing Code.
Exception: 
The buried portions of systems embedded underground.
1206.3 Protection of potable water. 
The potable water system sha
ll be protected from backflow in accordance with 
the 
New York City
Plumbing Code.
1206.4 Pipe penetrations. 
Openings for pipe penetrations in walls, floors or ceilings shall be larger than the penetrat-
ing pipe. Openings through concrete or masonry building
elements shall be sleeved. The annular space surrounding 
pipe penetrations shall be protected in accordance with the 
New York City
Building Code.
1206.5 Clearance to combustibles. 
A pipe in a hydronic piping system in which the exterior temperature exceed
s 
250°F (
121.1
°C) shall have a minimum clearance of 1 inch (25.4 mm) to combustible materials.
1206.6 Contact with building material. 
A hydronic piping system shall not be in direct contact with building mate-
rials that cause the piping material to degrade 
or corrode, or that interfere with the operation of the system.
1206.7 Water hammer. 
The flow velocity of the hydronic piping system shall be controlled to reduce the possibility 
of water hammer. Where a quick
-
closing valve creates water hammer, an 
enginee
red
water
-
hammer arrestor shall be 
installed. The arrestor shall be located within a range as specified by the manufacturer of the quick
-
closing valve.
1206.8 Steam piping pitch. 
Steam piping shall be installed to drain to the boiler or the steam trap. Ste
am systems 
shall not have drip pockets that reduce the capacity of the steam piping.
1206.9 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains and stresses in the pipe. 
Provisions shall be made to protect piping from damag
e resulting from expansion, contraction and structural settle-
ment. Piping shall be installed so as to avoid structural stresses or strains within building components.
1206.9.1 Flood hazard. 
Piping located in flood hazard areas 
shall comply with Appendix G
of 
the 
New York City 
Building Code
.
HYDRONIC PIPING
1206.10 Pipe support. 
Pipe shall be supported in accordance with Section 305.
Seismic supports shall be provided 
where required by the 
New York City Building Code.
1206.11 Condensation. 
Provisions shall be made to prevent the formation of condensation on the exterior of piping.
SECTION 
MC 
1207
TRANSFER FLUID
1207.1 Flash point. 
The
flash point of transfer fluid in a hydronic piping system shall be not less than 50°F (10°C) 
above the maximum system operating temperature.
1207.2 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
SECTION 
MC 
1208
TESTS
1208.1 General. 
Hydronic piping systems 
other than ground
-
source heat pump loop systems 
shall be tested hydro-
statically at one and one
half times the system design 
operating 
pressure, but not less than 100 psi (689 kPa). The 
duration of each 
test shall be not less than
2 hours. Ground
-
source heat pump loop systems shall be tested in accord-
ance with Section 1210.10.
SECTION 
MC 
1209
EMBEDDED PIPING
1209.1 Materials. 
Embedded piping
shall be plastic pipe or tubing
, in accordance with Section 1202
,
rated at 100 psi 
(689.5 kPa) at 180°F (82.2°C).
1209.2 Pressurizing during installation. 
Piping to be embedded in concrete shall be pressure tested prior to pouring 
concrete. During pouring, the pipe shall be maintained at the proposed operating pressure
.
1209.3 Embedded joints. 
Joints of pipe or tubing that are embedded in a portion of the building, such as concrete or 
plaster, shall be thermally
-
fused.
1209.4 Not embedded related piping. 
Joints of other piping in cavities or running exposed shall be joi
ned in accord-
ance with manufacturer’s instructions and related sections of this code.
1209.5 Thermal barrier required. 
Radiant floor heating systems shall be provided with a thermal barrier in accord-
ance with Sections 1209.5.1 through 1209.5.4.
Exception: 
Insulation shall not be required in engineered systems where it can be demonstrated that the insulation 
will decrease the efficiency or have a negative effect on the installation.
1209.5.1 Slab
-
on
-
grade installation. 
Radiant piping utilized in slab
-
on
-
grad
e applications shall be provided with 
insulating materials installed beneath the piping having a minimum R
-
value of 5.
1209.5.2 Suspended floor installation. 
In suspended floor applications, insulation shall be installed in the joist 
bay cavity serving the
heating space above and shall consist of materials having a minimum R
-
value of 11.
1209.5.3 Thermal break required. 
A thermal break shall be provided consisting of asphalt expansion joint mate-
rials or similar insulating materials at a point where a heated
slab meets a foundation wall or other conductive slab.
1209.5.4 Thermal barrier material marking. 
Insulating materials utilized in thermal barriers shall be installed 
such that the manufacturer’s R
-
value mark is readily observable upon inspection.
SECTION
MC 
1210
PLASTIC PIPE GROUND
-
SOURCE HEAT PUMP LOOP SYSTEMS
HYDRONIC PIPING
1210.1 Ground
-
source heat pump
-
loop water piping. 
Ground
-
source heat pump ground
-
loop piping and tubing 
material for water
-
based systems shall conform to the standards cited in this section.
1210.2
Used materials. 
Reused pipe, fittings, valves, and other materials shall not be permitted in ground
-
source heat 
pump loop systems.
1210.3 Material rating. 
Pipe and tubing shall be rated for the operating temperature and pressure of the ground
-
source heat 
pump loop system. Fittings shall be suitable for the pressure applications and recommended by the man-
ufacturer for installation with the pipe and tubing material installed. Where used underground, materials shall be suit-
able for burial.
1210.4 Piping and t
ubing materials standards. 
Ground
-
source heat pump ground
-
loop pipe and tubing shall con-
form to the standards listed in Table 1210.4.
TABLE 1210.4
GROUND
-
SOURCE LOOP PIPE
MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl chloride 
(CPVC)
ASTM D 
2846; ASTM F 
441; ASTM F 442
Cross
-
linked polyethylene (PEX)
ASTM F 876; ASTM F 877; 
CSA B137.5
Polyethylene/aluminum/polyethylen
e (PE
-
AL
-
PE) pressure pipe
ASTM F 1282; CSA B137.9
High
-
density polyethylene (HDPE)
ASTM D 2737; ASTM D 
3035; ASTM F 
714; AWWA 
C901; CSA B137.1; CSA 
C448; NSF 358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl chloride (PVC)
ASTM D 1785; ASTM D 
2241
Raised temperature polyethylene 
(PE
-
RT)
ASTM F 2623
1210.5 Fittings. 
Ground
-
source heat pump pipe fittings shall conform to the standards listed in Table 1210.5 and, if 
installed underground, shall be suitable for burial. 
TABLE 1210.5
GROUND
-
SOURCE LOOP PIPE FITTINGS
PIPE MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl 
chloride (CPVC)
ASTM D 2846; ASTM F 437; ASTM F 
438; ASTM F 439; CSA B137.6
Cross
-
linked 
polyethylene (PEX)
ASTM F 877; ASTM F 1807; ASTM F 
1960; ASTM F 2080; ASTM F 2159; 
ASTM F 2434; CSA B137.5
Polyethylene/aluminum/
polyethylene (PE
-
AL
-
PE)
ASTM F 1282; ASTM F 2434; CSA 
B137.9
HYDRONIC PIPING
High Density 
Polyethylene (HDPE)
ASTM D 2683; ASTM D 3261; ASTM 
F 1055; CSA B137.1; CSA C448; NSF 
358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl 
chloride 
(PVC)
ASTM D 2464; ASTM D 2466; ASTM 
D 2467; CSA B137.2; CSA B137.3
Raised temperature 
polyethylene (PE
-
RT)
ASTM D 3261; ASTM F 1807; ASTM 
F 2159; CSA B137.1
1210.6 Joints. 
Joints and connections, 
other than those covered by Section 1210 and co
nforming to the ASTM stand-
ards listed therein,
shall be of an approved type. Joints and connections shall be tight for the pressure of the ground
-
source loop system. Joints used underground shall be in accordance with manufacturer’s instructions for buried
appli-
cations.
1210.6.1 Joints between different piping materials. 
Joints between different piping materials shall be made with 
transition fittings compatible with both materials and the fluid contained within the system. Transition fittings must 
be used i
n accordance with manufacturer’s instructions.
1210.6.1.1 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not 
less than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same water line.
1210.6.2 Prep
aration of pipe ends. 
Pipe shall be cut square, be reamed, and be free of burrs and obstructions. 
CPVC, PE, and PVC pipe shall be chamfered. Pipe ends shall have full
-
bore openings and shall not be undercut.
1210.6.3 Joint preparation and installation. 
Whe
re required by Sections 1210.6.4 through 1210.6.6, the prepa-
ration and installation of mechanical and thermoplastic
-
welded joints shall comply with Sections 1210.6.3.1 and 
1210.6.3.2.
1210.6.3.1 Mechanical joints. 
Mechanical joints shall be installed in ac
cordance with the manufacturer’s in-
structions.
1210.6.3.2 Thermoplastic
-
welded joints. 
Joint surfaces for thermoplastic
-
welded joints shall be cleaned by a 
procedure in accordance with the manufacturer’s instructions. Joints shall be welded in accordance w
ith the 
manufacturer’s instructions.
1210.6.4 CPVC plastic pipe. 
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded 
joints complying with Section 1203.3.
‡‡‡
1210.6.5 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints bet
ween cross
-
linked polyethylene plastic 
tubing and fittings shall comply with Section 1210.6.5.1. Mechanical joints shall comply with Section 1210.6.3.
1210.6.5.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
r
ings, 
the fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1210.6.6 Polyethylene plastic pipe and tubing for ground
-
source heat pump loop systems. 
Joints between 
polyethylene plastic pipe and tubing or fittings for 
ground
-
source heat pump loop systems shall be heat fusion 
joints complying with Section 1210.6.6.1, electrofusion joints complying with Section 1210.6.6.2, or stab
-
type 
insertion joints complying with Section 1210.6.6.3.
1210.6.6.1 Heat
-
fusion joints. 
Joints shall be of the socket
-
fusion, saddle
-
fusion or butt
-
fusion type, joined in 
accordance with ASTM D 2657. Joint surfaces shall be clean and free from moisture. Joint surfaces shall be 
heated to melt temperatures and joi
ned. The joint shall be undisturbed until cool. Fittings shall be manufactured 
in accordance with ASTM D 2683 or ASTM D 3261.
1210.6.6.2 Electrofusion joints. 
Joints shall be of the electrofusion type. Joint surfaces shall be clean and free 
from moisture, 
and scoured to expose virgin resin. Joint surfaces shall be heated to melt temperatures for the 
HYDRONIC PIPING
period of time specified by the manufacturer. The joint shall be undisturbed until cool. Fittings shall be manu-
factured in accordance with ASTM F 1055.
1210.6.6
.3 Stab
-
type insert fittings. 
Joint surfaces shall be clean and free from moisture. Pipe ends shall be 
chamfered and inserted into the fittings to full depth. Fittings shall be manufactured in accordance with ASTM 
F 1924.
1210.6.7 Polypropylene (PP) plasti
c. 
Joints between PP plastic pipe and fittings shall comply with Sections 
1210.6.7.1 and 1210.6.7.2.
1210.6.7.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylen
e fittings, electrofusion polypropylene fittings or by butt fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1210.6.7.2 Mechanical and compression 
sleeve joints. 
Mechanical and compression sleeve joints shall be 
installed in accordance with the manufacturer’s instructions.
1210.6.8 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyeth-
ylene tubing and fittin
gs shall comply with Sections 1210.6.8.1 and 1210.6.8.2. Mechanical joints shall comply 
with Section 1210.6.3.
1210.6.8.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, 
the fittings shall be installed wi
thout omitting the inserts and ferrules or O
-
rings.
1210.6.9 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded 
joints comply with Section 1203.3.
1210.7 Shutoff valves. 
Shutoff valves shall be installed in
ground
-
source loop piping systems in the locations indi-
cated in Sections 1210.7.1 through 1210.7.7.
1210.7.1 Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
Exception: 
Shutoff valves shall not be requi
red where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1210
.7.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of a central utility 
system.
1210.7.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1210.7.4 Pressure
-
reducing valves.
Shutoff valves shall be installed on both sides of a pressure
-
reducing valve.
1210.7.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a gr
ound
-
source loop system such as pumps, air 
separators, metering devices, and similar equipment.
1210.7.6 Expansion tanks. 
Shutoff valves shall be installed at connections to nondiaphragm
-
type expansion tanks.
1210.7.7 Reduced pressure. 
A pressure relief va
lve shall be installed on the low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system 
design. The valve shall be installed in accordance with Section 1006.
1210.8 
Installation. 
Piping, valves, fittings, and connections shall be installed in accordance with the 
conditions of approval.
1210.8.1 Protection of potable water. 
Where ground
-
source heat pump ground
-
loop systems have a connection 
to a potable water supply, t
he potable water system shall be protected from backflow in accordance with the 
New 
York City Plumbing Code
.
1210.8.2 Pipe penetrations. 
Openings for pipe penetrations in walls, floors and ceilings shall be larger than the 
penetrating pipe. Openings throug
h concrete or masonry building elements shall be sleeved. The annular space 
surrounding pipe penetrations shall be protected in accordance with the 
New York City Building Code
.
HYDRONIC PIPING
1210.8.3 Clearance from combustibles. 
A pipe in a ground
-
source heat pump pipin
g system having an exterior 
surface temperature exceeding 250°F (121.1°C) shall have a minimum clearance of 1 inch (25.4 mm) from com-
bustible materials.
1210.8.4 Contact with building material. 
A ground
-
source heat pump ground
-
loop piping system shall not 
be in 
direct contact with building materials that cause the piping or fitting material to degrade or corrode, or that interfere 
with the operation of the system.
1210.8.5 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains 
and stresses in the pipe. 
Provisions shall be made to protect piping from damage resulting from expansion, contraction and structural set-
tlement. Piping shall be installed so as to avoid structural stresses or strains within building components.
1210.8.6 F
lood hazard. 
Piping located in a flood hazard area shall be capable of resisting hydrostatic and hydro-
dynamic loads and stresses, including the effects of buoyancy, during the occurrence of flooding to the design flood 
elevation.
1210.8.7 Pipe support. 
Pip
e shall be supported in accordance with Section 305.
1210.8.8 Velocities. 
Ground
-
source heat pump ground
-
loop systems shall be designed so that the flow velocities 
do not exceed the maximum flow velocity recommended by the pipe and fittings 
manufacturer and shall be con-
trolled to reduce the possibility of water hammer.
1210.8.9 Labeling and marking. 
Ground
-
source heat pump ground
-
loop system piping shall be marked with tape, 
metal tags or other method where it enters a building indicating “GR
OUND
-
SOURCE HEAT PUMP LOOP SYS-
TEM.” The marking shall indicate any antifreeze used in the system by name and concentration.
1210.8.10 Chemical compatibility. 
Antifreeze and other materials used in the system shall be chemically compat-
ible with the 
pipe, tubing, fittings, and mechanical systems.
1210.9 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
1210.10 Tests. 
Before connection header trenches are backfilled, the assembled loop system shall be pr
essure tested 
with water at 100 psi (689.5 kPa) for 15 minutes, in which time there shall not be observed leaks. Flow and pressure 
loss testing shall be performed and the actual flow rates and pressure drops shall be compared to the calculated design 
value
s. If actual flow rate or pressure drop values differ from calculated design values by more than 10 percent, the 
cause shall be identified and corrective action taken.
1210.11 Embedded piping. 
Ground
-
source heat pump ground
-
loop piping to be embedded in co
ncrete shall be pres-
sure tested prior to pouring concrete. During pouring, the pipe shall be maintained at the proposed operating pressure. 
Embedded piping shall comply with Section 1209.
SECTION MC 1211
HIGH
-
PRESSURE STEAM AND
HIGH TEMPERATURE HOT WATER P
IPING SYSTEMS
1211.1 Scope.
The provisions of this section shall apply to high
-
pressure steam piping system, which is defined as a 
system operating at a steam pressure of more than 15 psi (103.4 kPa), and high temperature water intended for 
operation at pr
essures in excess of 160 psi (1103.2 kPa) and temperatures in excess of 250°F (121.1°C). For purposes 
of this section, loops, bends or offsets of the piping shall not be considered expansion joints.
1211.2 New systems.
For purposes of this section, the rep
lacement of existing steam piping systems, the installation 
of a new system in existing buildings, as well as installations in buildings hereafter constructed, shall be considered 
to be new high
-
pressure steam piping systems. The following requirements are
applicable:
1211.2.1 Design.
The design of new steam piping systems shall be conducted as follows:
1.
The system shall be designed by an engineer. An application and plans shall be filed and the approval of the 
department obtained. The plans and applicati
on shall contain, but not be limited to, the following information:
1.1.
Size and location of all steam piping.
HYDRONIC PIPING
1.2.
The operating pressures and temperatures.
1.3.
The location, type, specifications and details of all expansion joints.
1.4.
The design, siz
e, material and location of all anchors, guides and auxiliary steel, and the stresses thereon.
2.
Systems using utility street steam shall be designed for a pressure of 200 psig (1379 kPa) and 413°F (211.7°C) 
up to and including the steam pressure reducing
valve or valves which reduce the pressure of 90 psig (620.5 
kPa) or below. For steam pressures between 90 psig (620.5 kPa) and 16 psig (110.3 kPa), the system shall be 
designed for 125 psig (861.8 kPa).
3.
Steam distribution systems utilizing pressure red
ucing valves.
3.1.
Safety Shutoff Valves (SSO) to protect downstream piping from overpressure shall be allowed in lieu of 
a safety relief valve vented to the outdoors as required by Section 1006.6.
3.2.
SSO shall be designed to automatically close at or be
low the design pressure of the downstream piping 
system that is being protected, to provide positive shutoff against full upstream pressure. Manual reset 
shall be required to reopen the SSO.
3.3.
SSO shall be designed in accordance with the Steam Distribut
ion Utility System requirements of the 
utility company having jurisdiction and ASME B31.1.
4.
Bellows expansion joints shall not be utilized on high pressure steam piping.
Exception: 
Bellows expansion joints shall be permitted for final connection to equip
ment where readily 
accessible for inspection and service and within Mechanical Equipment Rooms.
1211.2.2 Installation.
The installation of new steam piping systems shall be conducted as follows:
1.
Installations, including any welding, shall be subject to 
special inspection.
2.
Welders shall be qualified for all required pipe sizes, wall thicknesses and positions in accordance with the 
ASME
Boiler and Pressure Vessel Code,
Section IX. Requalification is required every five years or sooner 
if the commissione
r has a specific reason to doubt a welder’s ability to make acceptable welds.
3.
Welder qualification testing shall be performed by an approved agency listed with the department, and the 
inspector witnessing the test shall be an authorized AWS Certified We
lding Inspector. If the testing is by 
radiography, the test specimen shall be evaluated by personnel having a minimum radiography qualification 
of Level II in accordance with the ASNT, Document No. SNT
-
TC
-
1A, Supplement A. A successful radio-
graphic test of
a production weld made within the 6 months prior to requalification may be considered as an 
acceptable requalification test.
4.
Copies of the certified welder qualification reports shall be maintained by the responsible welding agency 
and the company perf
orming the welding, and shall be made available upon request to the department.
5.
No reports from any welding inspection agency shall be accepted unless such agency has first requested and 
obtained approval from the department in accordance with rules of 
the department.
6.
Pipe welding shall conform to the following:
6.1.
All piping over 2 inches (
50.8
mm) shall be butt
-
welded. Piping 2 inches (50.8 mm) and under may be 
socket
-
welded or threaded, providing Schedule 80 piping is utilized.
6.2.
Threaded piping may continue to be used for existing construction in size of 6 inches (
152.4
mm) and 
under.
6.3.
Where welding is not feasible, the commissioner may allow an acceptable alternative.
7.
Radiographic examination, when required, shall be performed on butt
-
welds in accordance with ASME 
B31.1 based on the piping system design pressure and shall be as foll
ows:
Piping System Design Pressure
Percentage
90 psig (620.5 kPa) or below
Not Required
HYDRONIC PIPING
91 psig (627.4 kPa) to
150 psig (1034.2 kPa)
10 at Random
Over 150 psig (1034.2 kPa)
100
However, if, in the opinion of the engineer responsible for special inspection, radiographic examination is not 
required for piping at pressure between 90 psig (620.5 kPa) and 150 psig (1034.2 kPa), the engineer shall so specify 
in writing, and the final r
eport on the installation may omit the foregoing, and be predicated on all of the other 
requirements noted in this section, and a hydrostatic test.
1211.2.3 Testing.
Hydrostatic testing shall be conducted on the completed installation at 150 percent of the
design 
pressure for all piping pressure. Where the changes in an existing steam system involve less than 30 percent of 
the piping in the system, the testing may be in accordance with ASME B31.1.
1211.2.4 Relocation.
The commissioner, where deemed necessar
y, shall require the replacement or relocation of 
any expansion joints, guides or anchors. The commissioner shall cause the expansion joints in potentially hazard-
ous locations, such as those that are located adjacent to tenant occupied spaces, to be reloca
ted, unless means exist 
or are provided for eliminating the hazard.
1211.3 Existing systems.
Existing steam piping systems shall be in accordance with Sections 1211.3.1 through 
1211.3.2. Upon the completion of a new high
-
pressure steam piping system and de
partment approval of same, the 
rules relating to maintenance requirements and the keeping of records for existing high
-
pressure steam piping sys-
tems shall apply.
1211.3.1 Maintenance inspections.
Expansion joints, anchorage and guides shall be inspected as
follows:
1.
Expansion joints shall be visually inspected monthly.
2.
The anchorage and guides shall be visually inspected annually. Exposure of the structural attachments to the 
buildings of the anchorages or guides shall not be required.
3.
A record of s
uch inspections shall be kept by the person in charge of the mechanical equipment of the building 
or other qualified person designated by the owner and acceptable to the commissioner. The records shall be 
available at the premises and subject to inspection
by the commissioner.
1211.3.2 Work approval.
No joint, anchorage or guides shall be repaired, replaced or relocated without a work 
permit issued by the department. The application for the permit shall contain all pertinent information and shall 
be filed by an engineer knowledgeable as to high
-
pressur
e steam piping systems. The engineer shall be responsible 
for the special inspection of the proposed work in accordance with the approved application. This provision shall 
not apply to the repacking of a slip or ball joint; however, records of such repacki
ng shall be kept in the inspection 
records as provided in Section 1211.3.1, Item 3. When, in the opinion of the engineer, the requirement for prior 
department approval would create an imminent health or safety hazard, the engineer may permit the work to 
pr
oceed without prior approval. In such cases, the engineer shall, prior to the repair, replacement or relocation, 
notify by telephone the borough commissioner of the borough in which the building is located; and, if the emer-
gency occurs at other than normal
working hours, he or she shall notify the department in a manner prescribed by 
the commissioner. This shall be followed by the filing of the application for department approval as specified in 
Section 28
-
105.4.1 of the 
Administrative Code
.
‡‡‡ Chapter 12 was amended by 
Local Law 
77 
of 2023
. This law has an effective
date of June 10, 2023.
CHAPTER 12
HYDRONIC PIPING 
SECTION MC 1201
GENERAL
1201.1 Scope. 
The provisions of this chapter shall govern the construction, installation, alteration and repair of hy-
dronic piping systems. This chapter shall apply to hydronic piping systems that are part of heating, ventilation and air
-
conditioning systems. Such piping systems shall include steam, hot water, chilled water, condenser water, cooling 
coil condensate drain, 
steam condensate and ground
-
source heat pump loop systems. Potable cold and hot water dis-
tribution systems shall be installed in accordance with the 
New York City
Plumbing Code
. 
1201.2 Sizing. 
Piping and piping system components for hydronic systems shall be sized for the 
design requirements
of the system.
1201.3 Standards. 
As an alternative to the provisions of Sections 1202 and 1203, piping shall be designed, installed, 
inspected and tested in accordance with ASME B31.
1 and ASME B31.9, as applicable
. 
SECTION 
MC 
1202
MATERIAL
1202.1 Piping. 
Piping material, other than those contained within this section and conforming with the ASTM stand-
ards listed within this chapter, shall be of an approved type.
Exception: 
Embedded piping regulated by Section 1209, and ground
-
source heat pump loop systems regulated by 
Section 1210.
1202.2 Used existing materials. 
Reused pipe, fittings, valves or other materials shall be clean and free of foreign 
materials.
1202.3 Material rating. 
Materials shall be rated for the operating temperature and pressure of the hydronic system. 
Materials shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards. 
Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior 
of the pipe shall be protected from corrosion and d
egradation.
TABLE 1202.4
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene 
(ABS) plastic pipe
ASTM D 1527; ASTM F 2806
Chlorinated polyvinyl chloride 
(CPVC) plastic pipe
ASTM D 2846; ASTM F 441; 
ASTM F 442
Copper, 
brass, or copper
-
alloy 
pipe
ASTM B 42; ASTM B 43; 
ASTM B 302
Copper, brass, or copper
-
alloy 
tube (Type K, L or M)
ASTM B 75; ASTM B 88; 
ASTM B 135; ASTM B 251
HYDRONIC PIPING
Cross
-
linked 
polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe
ASTM F 1281; CSA
B137.10
Cross
-
linked polyethylene 
(PEX) tubing
ASTM F 876; ASTM F 877
Ductile iron pipe
AWWA C115/A21.15; AWWA 
C151/A21.51 
Polyethylene/aluminum/
polyet
hylene 
(PE
-
AL
-
PE) pressure 
pipe
ASTM F 1282; CSA B137.9
Polypropylene (PP) 
plastic pipe
ASTM F 2389
Polyvinyl chloride (PVC) 
plastic pipe
ASTM D 1785; ASTM D 2241
Raised temperature 
polyethylene (PE
-
RT)
ASTM F 2623; ASTM F 2769
Steel pipe
ASTM A 53/A 53M; ASTM A 
106
Steel tubing
ASTM A 254
1202.5 Pipe fittings. 
Hydronic pipe fittings shall conform to the respective pipe standards or to the standards listed in 
Table 1202.5.
TABLE 1202.5
HYDRONIC PIPE FITTINGS
MATERIAL
STANDARD (see Chapter 15)
Copper, brass, and copper 
alloys
ASME B16.15; ASME B16.18; ASME 
B16.22; 
ASME B16.24; 
ASME 
B16.26; 
ASME B16.51; ASTM F 
1974 
Ductile iron and gray iron
ANSI/AWWA C110/A21.10; 
AWWA C153/A21.53; ASTM A 
126; ASTM A 395; ASTM A 536; 
ASTM F 1476; ASTM F 1548
Malleable iron
ASME B16.3
PE
-
RT fittings
ASTM F 1807; ASTM F 2098; 
ASTM F 2159; ASTM F 2735; 
ASTM F 2769
PEX fittings
ASTM F 877; ASTM F 1807; ASTM 
F 2159
Plastic
ASTM D 2466; ASTM D 2467; 
ASTM F 438; ASTM F 439; ASTM 
F
877; ASTM F 2389; ASTM F 2735
HYDRONIC PIPING
Steel
ASME B16.5; ASME 
B16.9; ASME 
B16.11; ASME B16.28; ASTM A 
53/A 53M; ASTM A 106; ASTM A 
234; ASTM A 420; ASTM A 536; 
ASTM A 395; ASTM F 1476; ASTM 
F 1548
1202.6 Valves. 
Valves shall be constructed of materials that are compatible with the type of piping material and fluids 
in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration compensators. 
Flexible connectors, expansion and vibration 
control devices and fit
tings
, when used, shall protect the components of the hydronic system from damage caused by 
expansion, contraction, transverse movement, angular deflection and vibration,
shall be 
rated for the temperatures 
and pressures of the systems in which the devices
are installed, and shall be compatible with the fluid and all materials 
provided
.
SECTION 
MC 
1203
JOINTS AND CONNECTIONS
1203.1 Approval. 
Joints and connections
, other than those contained in Section 1203 and conforming to the ASTM 
standards listed in Sec
tion 1203,
shall be of an approved type. Joints and connections shall be tight for the pressure 
of the hydronic system.
1203.1.1 Joints between different piping materials. 
Joints between different piping materials shall be 
rated for 
the temperatures and pr
essures of the systems in which the devices are installed and shall be compatible with the 
fluid and all materials provided. 
1203.
1.2 Joints between dissimilar metallic piping materials.
Joints between dissimilar metallic piping mate-
rials shall be provide
d to protect against galvanic corrosion. Such joints shall be 
made with 
dielectric fittings 
conforming to ANSI B16.39 or ASTM F 492, as applicable, shall be rated for the temperatures and pressures of 
the systems in which the devices are installed and shal
l be compatible with the fluid and all materials provided
.
Exception:
Dielectric fittings shall not be required for joints between dissimilar metal piping used within heat 
transfer appliances or equipment when such joints are provided by the appliance or e
quipment manufacturer, 
and such appliance or equipment is connected with isolation valves that are accessible.
1203.2 Preparation of pipe ends. 
Pipe shall be cut square, reamed and chamfered, and shall be free of burrs and 
obstructions. Pipe ends shall hav
e full
-
bore openings and shall not be undercut.
1203.3 Joint preparation and installation. 
Where required by Sections 1203.4 through 1203.14, the preparation and 
installation of brazed, mechanical, soldered, 
solvent
-
cemented
, threaded and welded joints shall comply with Sections 
1203.3.1 through 1203.3.8.
1203.3.1 Brazed joints.
All joints 
shall
be brazed with a 
brazing procedure developed and qualified in accordance 
with the ASME
Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications) or in accord-
ance with 
AWS 
B2.2 Standard for Brazing Procedure and Performance Qualifica
tion
.
1203.3.2 Mechanical joints. 
Mechanical joints shall be installed in accordance with the manufacturer’s instruc-
tions.
1203.3.3 Soldered joints. 
Joint surfaces shall be cleaned. A flux conforming to ASTM B 813 shall be applied. The 
joint shall be solde
red with a solder conforming to ASTM B 32.
1203.3.4 Solvent
-
cemented joints. 
Joint surfaces shall be clean and free of moisture. 
A
primer
, compatible with 
both the piping material and the cement
shall be applied to pipe
-
joint surfaces
, in accordance with t
he manufac-
turer’s requirements
. Joints shall be made while the cement is wet. Solvent cement conforming to the following 
standards shall be applied to all joint surfaces:
1.
ASTM D 2235 for ABS joints.
2.
ASTM F 493 for CPVC joints.
HYDRONIC PIPING
3.
ASTM D 2564 for PVC 
joints.
1203.3.5 Threaded joints. 
Threads shall conform to ASME B1.20.1. Schedule 80 or heavier plastic pipe shall be 
threaded with dies specifically designed for plastic pipe. Thread lubricant, pipe
-
joint compound or tape shall be 
applied on the male threads only and shall be 
compatible
f
or application on the piping material
and fluid
.
1203.3.6 Welded joints.
All joints shall be welded with a welding procedure developed and qualified in accord-
ance with the 
ASME Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications
) or in 
accordance with AWS B2.1 Specifications for Welding Procedure and Performance Qualification.
1203.3.7 Grooved and shouldered mechanical joints. 
Grooved and shouldered mechanical joints shall conform 
to the requirements of ASTM F 1476 and shall be i
nstalled in accordance with the manufacturer’s
instructions.
1203.3.8 Mechanically formed tee fittings. 
Mechanically extracted outlets shall have a height not less than three 
times the thickness of the branch tube wall.
1203.3.8.1 Full flow assurance. 
Bran
ch tubes shall not restrict the flow in the run tube. A dimple/depth stop 
shall be formed in the branch tube to ensure that penetration into the outlet is of the correct depth. For inspection 
purposes, a second dimple shall be placed
1
/
4
inch (6.4 mm) above the first dimple. Dimples shall be aligned 
with the tube run.
1203.3.8.2 Brazed joints. 
Mechanically formed tee fittings shall be brazed in accordance with Section 1203.3.1.
1203.4 ABS plastic pipe. 
Joints between ABS plastic pipe or f
ittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.5 Brass pipe. 
Joints between brass pipe or fittings shall be brazed, mechanical, threaded or welded joints con-
forming to Section 1203.3.
1203.6 Brass tubing. 
Joints bet
ween brass tubing or fittings shall be brazed, mechanical or soldered joints conforming 
to Section 1203.3.
1203.7 Copper or copper
-
alloy pipe. 
Joints between copper or copper
-
alloy pipe or fittings shall be brazed, mechan-
ical, soldered, threaded or welded 
joints conforming to Section 1203.3.
1203.8 Copper or copper
-
alloy tubing. 
Joints between copper or copper
-
alloy tubing or fittings shall be brazed, 
mechanical or soldered joints conforming to Section 1203.3, flared joints conforming to Section 1203.8.1
or
push
-
fit 
joints conforming to Section 1203.8.2.
1203.8.1 Flared joints. 
Flared joints shall be made by a tool designed for that operation.
1203.8.2 Push
-
fit joints. 
Push
-
fit joints shall be installed in accordance with the manufacturer’s instructions.
120
3.9 CPVC plastic pipe.   
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.10 Reserved.
1203.11 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints between cross
-
linked polyethyle
ne plastic tubing 
and fittings shall conform to Sections 1203.11.1 and 1203.11.2. Mechanical joints shall conform to Section 1203.3.
1203.11.1 Compression
-
type fittings. 
Where
compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings 
shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.11.2 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not less 
than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same 
water line.
1203.12 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.13 Steel pipe. 
Joints between steel pipe or fittings shall be mechanical
, threaded or welded 
joints 
conforming to 
Section 1203.3.
1203.14 Steel tubing. 
Joints between steel tubing or fittings shall be mechanical or welded joints conforming to Sec-
tion 1203.3.
HYDRONIC PIPING
1203.15 Polypropylene (PP) plastic. 
Joints between PP plastic pipe and fittings shall comp
ly with Sections 1203.15.1 
and 1203.15.2.
1203.15.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylene fittings, electro
-
fusion polypropylene fittings or by butt
fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1203.15.2 Mechanical and compression sleeve joints. 
Mechanical and compression sleeve joints shal
l be installed 
in accordance with the manufacturer’s instructions.
1203.16 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyethylene 
tubing and fittings shall conform to Sections 1203.16.1 and 1203.16.2. Mechani
cal joints shall conform to Section 
1203.3.
1203.16.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.16.2 PE
-
RT
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 mm) 
of a transition from such metal pipe to PE
-
RT pipe.
1203.17 Polyethylene/aluminum/polyethylene (PE
-
AL
-
PE) pressure pipe. 
Joints between polyethylene/alumi-
num/po
lyethylene pressure pipe and fittings shall conform to Sections 1203.17.1 and 1203.17.2. Mechanical joints 
shall comply with Section 1203.3.
1203.17.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
f
ittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.17.2 PE
-
AL
-
PE
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 
mm) of a transition from such metal pipe to PE
-
AL
-
PE pipe.
1203.18 Cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe. 
Joints 
between cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene pressure pipe and fittings shall conform to 
Sections 1203.18.1 and 1203.18.2. Mecha
nical joints shall comply with Section 1203.3.
1203.18.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.18.2 PEX
-
AL
-
PEX
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches 
(457.2 mm) of a transition from such metal pipe to PEX
-
AL
-
PEX pipe.
SECTION 
MC 
1204
PIPE INSULATION
1204.1 Insulation characteristics. 
Pipe insulation installed in buildings shall conform to the requirements of the 
New 
York City
Energy Conservation Code
,
shall be tested in accordance with ASTM E 84 or UL 723, using the specimen 
preparation and mounting p
rocedures of ASTM E 2231; and shall have a maximum flame spread index of 25 and a 
smoke
-
developed index not exceeding 450. Insulation installed in an air plenum shall comply with Section 602.2.1.
1204.2 Required thickness. 
Hydronic piping shall be insulate
d to the thickness required by the 
New York City
Energy 
Conservation Code.
SECTION 
MC 
1205
VALVES
1205.1 Where required. 
Shutoff valves shall be installed in hydronic piping systems in the locations indicated in 
Sections 1205.1.1 through 1205.1.6.
1205.1.1
Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
HYDRONIC PIPING
Exception: 
Shutoff valves shall not be required where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat 
exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1205.1.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of central utility 
systems, and district
heating and cooling 
systems.
1205.1.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1205.1.4 Pressure
-
reducing valves. 
Shutoff valves shall be installed on both sides of a pressure
-
reduc
ing valve.
1205.1.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a hydronic system such as pumps, air separators, 
metering devices and si
milar equipment.
1205.1.6 Expansion tanks.
Lockable shutoff
valves shall be installed at connections to 
all
expansion tanks.
Valves shall be locked in the open position.
1205.2 Reduced pressure. 
A pressure relief valve shall be installed on the 
low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system design. 
The valve shall be installed in accordance with Section 1006.
SECTION 
MC 
1206
PIPING INSTALLATION
1
206.1 General. 
Piping, valves, fittings and connections shall be installed in accordance with the conditions of ap-
proval.
1206.2 System drain down. 
Hydronic piping systems shall be designed and installed to permit the system to be 
drained. Where the system
drains to the plumbing drainage system, the installation shall conform to the requirements 
of the 
New York City
Plumbing Code.
Exception: 
The buried portions of systems embedded underground.
1206.3 Protection of potable water. 
The potable water system sha
ll be protected from backflow in accordance with 
the 
New York City
Plumbing Code.
1206.4 Pipe penetrations. 
Openings for pipe penetrations in walls, floors or ceilings shall be larger than the penetrat-
ing pipe. Openings through concrete or masonry building
elements shall be sleeved. The annular space surrounding 
pipe penetrations shall be protected in accordance with the 
New York City
Building Code.
1206.5 Clearance to combustibles. 
A pipe in a hydronic piping system in which the exterior temperature exceed
s 
250°F (
121.1
°C) shall have a minimum clearance of 1 inch (25.4 mm) to combustible materials.
1206.6 Contact with building material. 
A hydronic piping system shall not be in direct contact with building mate-
rials that cause the piping material to degrade 
or corrode, or that interfere with the operation of the system.
1206.7 Water hammer. 
The flow velocity of the hydronic piping system shall be controlled to reduce the possibility 
of water hammer. Where a quick
-
closing valve creates water hammer, an 
enginee
red
water
-
hammer arrestor shall be 
installed. The arrestor shall be located within a range as specified by the manufacturer of the quick
-
closing valve.
1206.8 Steam piping pitch. 
Steam piping shall be installed to drain to the boiler or the steam trap. Ste
am systems 
shall not have drip pockets that reduce the capacity of the steam piping.
1206.9 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains and stresses in the pipe. 
Provisions shall be made to protect piping from damag
e resulting from expansion, contraction and structural settle-
ment. Piping shall be installed so as to avoid structural stresses or strains within building components.
1206.9.1 Flood hazard. 
Piping located in flood hazard areas 
shall comply with Appendix G
of 
the 
New York City 
Building Code
.
HYDRONIC PIPING
1206.10 Pipe support. 
Pipe shall be supported in accordance with Section 305.
Seismic supports shall be provided 
where required by the 
New York City Building Code.
1206.11 Condensation. 
Provisions shall be made to prevent the formation of condensation on the exterior of piping.
SECTION 
MC 
1207
TRANSFER FLUID
1207.1 Flash point. 
The
flash point of transfer fluid in a hydronic piping system shall be not less than 50°F (10°C) 
above the maximum system operating temperature.
1207.2 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
SECTION 
MC 
1208
TESTS
1208.1 General. 
Hydronic piping systems 
other than ground
-
source heat pump loop systems 
shall be tested hydro-
statically at one and one
half times the system design 
operating 
pressure, but not less than 100 psi (689 kPa). The 
duration of each 
test shall be not less than
2 hours. Ground
-
source heat pump loop systems shall be tested in accord-
ance with Section 1210.10.
SECTION 
MC 
1209
EMBEDDED PIPING
1209.1 Materials. 
Embedded piping
shall be plastic pipe or tubing
, in accordance with Section 1202
,
rated at 100 psi 
(689.5 kPa) at 180°F (82.2°C).
1209.2 Pressurizing during installation. 
Piping to be embedded in concrete shall be pressure tested prior to pouring 
concrete. During pouring, the pipe shall be maintained at the proposed operating pressure
.
1209.3 Embedded joints. 
Joints of pipe or tubing that are embedded in a portion of the building, such as concrete or 
plaster, shall be thermally
-
fused.
1209.4 Not embedded related piping. 
Joints of other piping in cavities or running exposed shall be joi
ned in accord-
ance with manufacturer’s instructions and related sections of this code.
1209.5 Thermal barrier required. 
Radiant floor heating systems shall be provided with a thermal barrier in accord-
ance with Sections 1209.5.1 through 1209.5.4.
Exception: 
Insulation shall not be required in engineered systems where it can be demonstrated that the insulation 
will decrease the efficiency or have a negative effect on the installation.
1209.5.1 Slab
-
on
-
grade installation. 
Radiant piping utilized in slab
-
on
-
grad
e applications shall be provided with 
insulating materials installed beneath the piping having a minimum R
-
value of 5.
1209.5.2 Suspended floor installation. 
In suspended floor applications, insulation shall be installed in the joist 
bay cavity serving the
heating space above and shall consist of materials having a minimum R
-
value of 11.
1209.5.3 Thermal break required. 
A thermal break shall be provided consisting of asphalt expansion joint mate-
rials or similar insulating materials at a point where a heated
slab meets a foundation wall or other conductive slab.
1209.5.4 Thermal barrier material marking. 
Insulating materials utilized in thermal barriers shall be installed 
such that the manufacturer’s R
-
value mark is readily observable upon inspection.
SECTION
MC 
1210
PLASTIC PIPE GROUND
-
SOURCE HEAT PUMP LOOP SYSTEMS
HYDRONIC PIPING
1210.1 Ground
-
source heat pump
-
loop water piping. 
Ground
-
source heat pump ground
-
loop piping and tubing 
material for water
-
based systems shall conform to the standards cited in this section.
1210.2
Used materials. 
Reused pipe, fittings, valves, and other materials shall not be permitted in ground
-
source heat 
pump loop systems.
1210.3 Material rating. 
Pipe and tubing shall be rated for the operating temperature and pressure of the ground
-
source heat 
pump loop system. Fittings shall be suitable for the pressure applications and recommended by the man-
ufacturer for installation with the pipe and tubing material installed. Where used underground, materials shall be suit-
able for burial.
1210.4 Piping and t
ubing materials standards. 
Ground
-
source heat pump ground
-
loop pipe and tubing shall con-
form to the standards listed in Table 1210.4.
TABLE 1210.4
GROUND
-
SOURCE LOOP PIPE
MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl chloride 
(CPVC)
ASTM D 
2846; ASTM F 
441; ASTM F 442
Cross
-
linked polyethylene (PEX)
ASTM F 876; ASTM F 877; 
CSA B137.5
Polyethylene/aluminum/polyethylen
e (PE
-
AL
-
PE) pressure pipe
ASTM F 1282; CSA B137.9
High
-
density polyethylene (HDPE)
ASTM D 2737; ASTM D 
3035; ASTM F 
714; AWWA 
C901; CSA B137.1; CSA 
C448; NSF 358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl chloride (PVC)
ASTM D 1785; ASTM D 
2241
Raised temperature polyethylene 
(PE
-
RT)
ASTM F 2623
1210.5 Fittings. 
Ground
-
source heat pump pipe fittings shall conform to the standards listed in Table 1210.5 and, if 
installed underground, shall be suitable for burial. 
TABLE 1210.5
GROUND
-
SOURCE LOOP PIPE FITTINGS
PIPE MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl 
chloride (CPVC)
ASTM D 2846; ASTM F 437; ASTM F 
438; ASTM F 439; CSA B137.6
Cross
-
linked 
polyethylene (PEX)
ASTM F 877; ASTM F 1807; ASTM F 
1960; ASTM F 2080; ASTM F 2159; 
ASTM F 2434; CSA B137.5
Polyethylene/aluminum/
polyethylene (PE
-
AL
-
PE)
ASTM F 1282; ASTM F 2434; CSA 
B137.9
HYDRONIC PIPING
High Density 
Polyethylene (HDPE)
ASTM D 2683; ASTM D 3261; ASTM 
F 1055; CSA B137.1; CSA C448; NSF 
358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl 
chloride 
(PVC)
ASTM D 2464; ASTM D 2466; ASTM 
D 2467; CSA B137.2; CSA B137.3
Raised temperature 
polyethylene (PE
-
RT)
ASTM D 3261; ASTM F 1807; ASTM 
F 2159; CSA B137.1
1210.6 Joints. 
Joints and connections, 
other than those covered by Section 1210 and co
nforming to the ASTM stand-
ards listed therein,
shall be of an approved type. Joints and connections shall be tight for the pressure of the ground
-
source loop system. Joints used underground shall be in accordance with manufacturer’s instructions for buried
appli-
cations.
1210.6.1 Joints between different piping materials. 
Joints between different piping materials shall be made with 
transition fittings compatible with both materials and the fluid contained within the system. Transition fittings must 
be used i
n accordance with manufacturer’s instructions.
1210.6.1.1 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not 
less than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same water line.
1210.6.2 Prep
aration of pipe ends. 
Pipe shall be cut square, be reamed, and be free of burrs and obstructions. 
CPVC, PE, and PVC pipe shall be chamfered. Pipe ends shall have full
-
bore openings and shall not be undercut.
1210.6.3 Joint preparation and installation. 
Whe
re required by Sections 1210.6.4 through 1210.6.6, the prepa-
ration and installation of mechanical and thermoplastic
-
welded joints shall comply with Sections 1210.6.3.1 and 
1210.6.3.2.
1210.6.3.1 Mechanical joints. 
Mechanical joints shall be installed in ac
cordance with the manufacturer’s in-
structions.
1210.6.3.2 Thermoplastic
-
welded joints. 
Joint surfaces for thermoplastic
-
welded joints shall be cleaned by a 
procedure in accordance with the manufacturer’s instructions. Joints shall be welded in accordance w
ith the 
manufacturer’s instructions.
1210.6.4 CPVC plastic pipe. 
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded 
joints complying with Section 1203.3.
‡‡‡
1210.6.5 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints bet
ween cross
-
linked polyethylene plastic 
tubing and fittings shall comply with Section 1210.6.5.1. Mechanical joints shall comply with Section 1210.6.3.
1210.6.5.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
r
ings, 
the fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1210.6.6 Polyethylene plastic pipe and tubing for ground
-
source heat pump loop systems. 
Joints between 
polyethylene plastic pipe and tubing or fittings for 
ground
-
source heat pump loop systems shall be heat fusion 
joints complying with Section 1210.6.6.1, electrofusion joints complying with Section 1210.6.6.2, or stab
-
type 
insertion joints complying with Section 1210.6.6.3.
1210.6.6.1 Heat
-
fusion joints. 
Joints shall be of the socket
-
fusion, saddle
-
fusion or butt
-
fusion type, joined in 
accordance with ASTM D 2657. Joint surfaces shall be clean and free from moisture. Joint surfaces shall be 
heated to melt temperatures and joi
ned. The joint shall be undisturbed until cool. Fittings shall be manufactured 
in accordance with ASTM D 2683 or ASTM D 3261.
1210.6.6.2 Electrofusion joints. 
Joints shall be of the electrofusion type. Joint surfaces shall be clean and free 
from moisture, 
and scoured to expose virgin resin. Joint surfaces shall be heated to melt temperatures for the 
HYDRONIC PIPING
period of time specified by the manufacturer. The joint shall be undisturbed until cool. Fittings shall be manu-
factured in accordance with ASTM F 1055.
1210.6.6
.3 Stab
-
type insert fittings. 
Joint surfaces shall be clean and free from moisture. Pipe ends shall be 
chamfered and inserted into the fittings to full depth. Fittings shall be manufactured in accordance with ASTM 
F 1924.
1210.6.7 Polypropylene (PP) plasti
c. 
Joints between PP plastic pipe and fittings shall comply with Sections 
1210.6.7.1 and 1210.6.7.2.
1210.6.7.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylen
e fittings, electrofusion polypropylene fittings or by butt fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1210.6.7.2 Mechanical and compression 
sleeve joints. 
Mechanical and compression sleeve joints shall be 
installed in accordance with the manufacturer’s instructions.
1210.6.8 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyeth-
ylene tubing and fittin
gs shall comply with Sections 1210.6.8.1 and 1210.6.8.2. Mechanical joints shall comply 
with Section 1210.6.3.
1210.6.8.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, 
the fittings shall be installed wi
thout omitting the inserts and ferrules or O
-
rings.
1210.6.9 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded 
joints comply with Section 1203.3.
1210.7 Shutoff valves. 
Shutoff valves shall be installed in
ground
-
source loop piping systems in the locations indi-
cated in Sections 1210.7.1 through 1210.7.7.
1210.7.1 Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
Exception: 
Shutoff valves shall not be requi
red where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1210
.7.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of a central utility 
system.
1210.7.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1210.7.4 Pressure
-
reducing valves.
Shutoff valves shall be installed on both sides of a pressure
-
reducing valve.
1210.7.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a gr
ound
-
source loop system such as pumps, air 
separators, metering devices, and similar equipment.
1210.7.6 Expansion tanks. 
Shutoff valves shall be installed at connections to nondiaphragm
-
type expansion tanks.
1210.7.7 Reduced pressure. 
A pressure relief va
lve shall be installed on the low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system 
design. The valve shall be installed in accordance with Section 1006.
1210.8 
Installation. 
Piping, valves, fittings, and connections shall be installed in accordance with the 
conditions of approval.
1210.8.1 Protection of potable water. 
Where ground
-
source heat pump ground
-
loop systems have a connection 
to a potable water supply, t
he potable water system shall be protected from backflow in accordance with the 
New 
York City Plumbing Code
.
1210.8.2 Pipe penetrations. 
Openings for pipe penetrations in walls, floors and ceilings shall be larger than the 
penetrating pipe. Openings throug
h concrete or masonry building elements shall be sleeved. The annular space 
surrounding pipe penetrations shall be protected in accordance with the 
New York City Building Code
.
HYDRONIC PIPING
1210.8.3 Clearance from combustibles. 
A pipe in a ground
-
source heat pump pipin
g system having an exterior 
surface temperature exceeding 250°F (121.1°C) shall have a minimum clearance of 1 inch (25.4 mm) from com-
bustible materials.
1210.8.4 Contact with building material. 
A ground
-
source heat pump ground
-
loop piping system shall not 
be in 
direct contact with building materials that cause the piping or fitting material to degrade or corrode, or that interfere 
with the operation of the system.
1210.8.5 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains 
and stresses in the pipe. 
Provisions shall be made to protect piping from damage resulting from expansion, contraction and structural set-
tlement. Piping shall be installed so as to avoid structural stresses or strains within building components.
1210.8.6 F
lood hazard. 
Piping located in a flood hazard area shall be capable of resisting hydrostatic and hydro-
dynamic loads and stresses, including the effects of buoyancy, during the occurrence of flooding to the design flood 
elevation.
1210.8.7 Pipe support. 
Pip
e shall be supported in accordance with Section 305.
1210.8.8 Velocities. 
Ground
-
source heat pump ground
-
loop systems shall be designed so that the flow velocities 
do not exceed the maximum flow velocity recommended by the pipe and fittings 
manufacturer and shall be con-
trolled to reduce the possibility of water hammer.
1210.8.9 Labeling and marking. 
Ground
-
source heat pump ground
-
loop system piping shall be marked with tape, 
metal tags or other method where it enters a building indicating “GR
OUND
-
SOURCE HEAT PUMP LOOP SYS-
TEM.” The marking shall indicate any antifreeze used in the system by name and concentration.
1210.8.10 Chemical compatibility. 
Antifreeze and other materials used in the system shall be chemically compat-
ible with the 
pipe, tubing, fittings, and mechanical systems.
1210.9 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
1210.10 Tests. 
Before connection header trenches are backfilled, the assembled loop system shall be pr
essure tested 
with water at 100 psi (689.5 kPa) for 15 minutes, in which time there shall not be observed leaks. Flow and pressure 
loss testing shall be performed and the actual flow rates and pressure drops shall be compared to the calculated design 
value
s. If actual flow rate or pressure drop values differ from calculated design values by more than 10 percent, the 
cause shall be identified and corrective action taken.
1210.11 Embedded piping. 
Ground
-
source heat pump ground
-
loop piping to be embedded in co
ncrete shall be pres-
sure tested prior to pouring concrete. During pouring, the pipe shall be maintained at the proposed operating pressure. 
Embedded piping shall comply with Section 1209.
SECTION MC 1211
HIGH
-
PRESSURE STEAM AND
HIGH TEMPERATURE HOT WATER P
IPING SYSTEMS
1211.1 Scope.
The provisions of this section shall apply to high
-
pressure steam piping system, which is defined as a 
system operating at a steam pressure of more than 15 psi (103.4 kPa), and high temperature water intended for 
operation at pr
essures in excess of 160 psi (1103.2 kPa) and temperatures in excess of 250°F (121.1°C). For purposes 
of this section, loops, bends or offsets of the piping shall not be considered expansion joints.
1211.2 New systems.
For purposes of this section, the rep
lacement of existing steam piping systems, the installation 
of a new system in existing buildings, as well as installations in buildings hereafter constructed, shall be considered 
to be new high
-
pressure steam piping systems. The following requirements are
applicable:
1211.2.1 Design.
The design of new steam piping systems shall be conducted as follows:
1.
The system shall be designed by an engineer. An application and plans shall be filed and the approval of the 
department obtained. The plans and applicati
on shall contain, but not be limited to, the following information:
1.1.
Size and location of all steam piping.
HYDRONIC PIPING
1.2.
The operating pressures and temperatures.
1.3.
The location, type, specifications and details of all expansion joints.
1.4.
The design, siz
e, material and location of all anchors, guides and auxiliary steel, and the stresses thereon.
2.
Systems using utility street steam shall be designed for a pressure of 200 psig (1379 kPa) and 413°F (211.7°C) 
up to and including the steam pressure reducing
valve or valves which reduce the pressure of 90 psig (620.5 
kPa) or below. For steam pressures between 90 psig (620.5 kPa) and 16 psig (110.3 kPa), the system shall be 
designed for 125 psig (861.8 kPa).
3.
Steam distribution systems utilizing pressure red
ucing valves.
3.1.
Safety Shutoff Valves (SSO) to protect downstream piping from overpressure shall be allowed in lieu of 
a safety relief valve vented to the outdoors as required by Section 1006.6.
3.2.
SSO shall be designed to automatically close at or be
low the design pressure of the downstream piping 
system that is being protected, to provide positive shutoff against full upstream pressure. Manual reset 
shall be required to reopen the SSO.
3.3.
SSO shall be designed in accordance with the Steam Distribut
ion Utility System requirements of the 
utility company having jurisdiction and ASME B31.1.
4.
Bellows expansion joints shall not be utilized on high pressure steam piping.
Exception: 
Bellows expansion joints shall be permitted for final connection to equip
ment where readily 
accessible for inspection and service and within Mechanical Equipment Rooms.
1211.2.2 Installation.
The installation of new steam piping systems shall be conducted as follows:
1.
Installations, including any welding, shall be subject to 
special inspection.
2.
Welders shall be qualified for all required pipe sizes, wall thicknesses and positions in accordance with the 
ASME
Boiler and Pressure Vessel Code,
Section IX. Requalification is required every five years or sooner 
if the commissione
r has a specific reason to doubt a welder’s ability to make acceptable welds.
3.
Welder qualification testing shall be performed by an approved agency listed with the department, and the 
inspector witnessing the test shall be an authorized AWS Certified We
lding Inspector. If the testing is by 
radiography, the test specimen shall be evaluated by personnel having a minimum radiography qualification 
of Level II in accordance with the ASNT, Document No. SNT
-
TC
-
1A, Supplement A. A successful radio-
graphic test of
a production weld made within the 6 months prior to requalification may be considered as an 
acceptable requalification test.
4.
Copies of the certified welder qualification reports shall be maintained by the responsible welding agency 
and the company perf
orming the welding, and shall be made available upon request to the department.
5.
No reports from any welding inspection agency shall be accepted unless such agency has first requested and 
obtained approval from the department in accordance with rules of 
the department.
6.
Pipe welding shall conform to the following:
6.1.
All piping over 2 inches (
50.8
mm) shall be butt
-
welded. Piping 2 inches (50.8 mm) and under may be 
socket
-
welded or threaded, providing Schedule 80 piping is utilized.
6.2.
Threaded piping may continue to be used for existing construction in size of 6 inches (
152.4
mm) and 
under.
6.3.
Where welding is not feasible, the commissioner may allow an acceptable alternative.
7.
Radiographic examination, when required, shall be performed on butt
-
welds in accordance with ASME 
B31.1 based on the piping system design pressure and shall be as foll
ows:
Piping System Design Pressure
Percentage
90 psig (620.5 kPa) or below
Not Required
HYDRONIC PIPING
91 psig (627.4 kPa) to
150 psig (1034.2 kPa)
10 at Random
Over 150 psig (1034.2 kPa)
100
However, if, in the opinion of the engineer responsible for special inspection, radiographic examination is not 
required for piping at pressure between 90 psig (620.5 kPa) and 150 psig (1034.2 kPa), the engineer shall so specify 
in writing, and the final r
eport on the installation may omit the foregoing, and be predicated on all of the other 
requirements noted in this section, and a hydrostatic test.
1211.2.3 Testing.
Hydrostatic testing shall be conducted on the completed installation at 150 percent of the
design 
pressure for all piping pressure. Where the changes in an existing steam system involve less than 30 percent of 
the piping in the system, the testing may be in accordance with ASME B31.1.
1211.2.4 Relocation.
The commissioner, where deemed necessar
y, shall require the replacement or relocation of 
any expansion joints, guides or anchors. The commissioner shall cause the expansion joints in potentially hazard-
ous locations, such as those that are located adjacent to tenant occupied spaces, to be reloca
ted, unless means exist 
or are provided for eliminating the hazard.
1211.3 Existing systems.
Existing steam piping systems shall be in accordance with Sections 1211.3.1 through 
1211.3.2. Upon the completion of a new high
-
pressure steam piping system and de
partment approval of same, the 
rules relating to maintenance requirements and the keeping of records for existing high
-
pressure steam piping sys-
tems shall apply.
1211.3.1 Maintenance inspections.
Expansion joints, anchorage and guides shall be inspected as
follows:
1.
Expansion joints shall be visually inspected monthly.
2.
The anchorage and guides shall be visually inspected annually. Exposure of the structural attachments to the 
buildings of the anchorages or guides shall not be required.
3.
A record of s
uch inspections shall be kept by the person in charge of the mechanical equipment of the building 
or other qualified person designated by the owner and acceptable to the commissioner. The records shall be 
available at the premises and subject to inspection
by the commissioner.
1211.3.2 Work approval.
No joint, anchorage or guides shall be repaired, replaced or relocated without a work 
permit issued by the department. The application for the permit shall contain all pertinent information and shall 
be filed by an engineer knowledgeable as to high
-
pressur
e steam piping systems. The engineer shall be responsible 
for the special inspection of the proposed work in accordance with the approved application. This provision shall 
not apply to the repacking of a slip or ball joint; however, records of such repacki
ng shall be kept in the inspection 
records as provided in Section 1211.3.1, Item 3. When, in the opinion of the engineer, the requirement for prior 
department approval would create an imminent health or safety hazard, the engineer may permit the work to 
pr
oceed without prior approval. In such cases, the engineer shall, prior to the repair, replacement or relocation, 
notify by telephone the borough commissioner of the borough in which the building is located; and, if the emer-
gency occurs at other than normal
working hours, he or she shall notify the department in a manner prescribed by 
the commissioner. This shall be followed by the filing of the application for department approval as specified in 
Section 28
-
105.4.1 of the 
Administrative Code
.
‡‡‡ Chapter 12 was amended by 
Local Law 
77 
of 2023
. This law has an effective
date of June 10, 2023.
CHAPTER 12
HYDRONIC PIPING 
SECTION MC 1201
GENERAL
1201.1 Scope. 
The provisions of this chapter shall govern the construction, installation, alteration and repair of hy-
dronic piping systems. This chapter shall apply to hydronic piping systems that are part of heating, ventilation and air
-
conditioning systems. Such piping systems shall include steam, hot water, chilled water, condenser water, cooling 
coil condensate drain, 
steam condensate and ground
-
source heat pump loop systems. Potable cold and hot water dis-
tribution systems shall be installed in accordance with the 
New York City
Plumbing Code
. 
1201.2 Sizing. 
Piping and piping system components for hydronic systems shall be sized for the 
design requirements
of the system.
1201.3 Standards. 
As an alternative to the provisions of Sections 1202 and 1203, piping shall be designed, installed, 
inspected and tested in accordance with ASME B31.
1 and ASME B31.9, as applicable
. 
SECTION 
MC 
1202
MATERIAL
1202.1 Piping. 
Piping material, other than those contained within this section and conforming with the ASTM stand-
ards listed within this chapter, shall be of an approved type.
Exception: 
Embedded piping regulated by Section 1209, and ground
-
source heat pump loop systems regulated by 
Section 1210.
1202.2 Used existing materials. 
Reused pipe, fittings, valves or other materials shall be clean and free of foreign 
materials.
1202.3 Material rating. 
Materials shall be rated for the operating temperature and pressure of the hydronic system. 
Materials shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards. 
Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior 
of the pipe shall be protected from corrosion and d
egradation.
TABLE 1202.4
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene 
(ABS) plastic pipe
ASTM D 1527; ASTM F 2806
Chlorinated polyvinyl chloride 
(CPVC) plastic pipe
ASTM D 2846; ASTM F 441; 
ASTM F 442
Copper, 
brass, or copper
-
alloy 
pipe
ASTM B 42; ASTM B 43; 
ASTM B 302
Copper, brass, or copper
-
alloy 
tube (Type K, L or M)
ASTM B 75; ASTM B 88; 
ASTM B 135; ASTM B 251
HYDRONIC PIPING
Cross
-
linked 
polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe
ASTM F 1281; CSA
B137.10
Cross
-
linked polyethylene 
(PEX) tubing
ASTM F 876; ASTM F 877
Ductile iron pipe
AWWA C115/A21.15; AWWA 
C151/A21.51 
Polyethylene/aluminum/
polyet
hylene 
(PE
-
AL
-
PE) pressure 
pipe
ASTM F 1282; CSA B137.9
Polypropylene (PP) 
plastic pipe
ASTM F 2389
Polyvinyl chloride (PVC) 
plastic pipe
ASTM D 1785; ASTM D 2241
Raised temperature 
polyethylene (PE
-
RT)
ASTM F 2623; ASTM F 2769
Steel pipe
ASTM A 53/A 53M; ASTM A 
106
Steel tubing
ASTM A 254
1202.5 Pipe fittings. 
Hydronic pipe fittings shall conform to the respective pipe standards or to the standards listed in 
Table 1202.5.
TABLE 1202.5
HYDRONIC PIPE FITTINGS
MATERIAL
STANDARD (see Chapter 15)
Copper, brass, and copper 
alloys
ASME B16.15; ASME B16.18; ASME 
B16.22; 
ASME B16.24; 
ASME 
B16.26; 
ASME B16.51; ASTM F 
1974 
Ductile iron and gray iron
ANSI/AWWA C110/A21.10; 
AWWA C153/A21.53; ASTM A 
126; ASTM A 395; ASTM A 536; 
ASTM F 1476; ASTM F 1548
Malleable iron
ASME B16.3
PE
-
RT fittings
ASTM F 1807; ASTM F 2098; 
ASTM F 2159; ASTM F 2735; 
ASTM F 2769
PEX fittings
ASTM F 877; ASTM F 1807; ASTM 
F 2159
Plastic
ASTM D 2466; ASTM D 2467; 
ASTM F 438; ASTM F 439; ASTM 
F
877; ASTM F 2389; ASTM F 2735
HYDRONIC PIPING
Steel
ASME B16.5; ASME 
B16.9; ASME 
B16.11; ASME B16.28; ASTM A 
53/A 53M; ASTM A 106; ASTM A 
234; ASTM A 420; ASTM A 536; 
ASTM A 395; ASTM F 1476; ASTM 
F 1548
1202.6 Valves. 
Valves shall be constructed of materials that are compatible with the type of piping material and fluids 
in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration compensators. 
Flexible connectors, expansion and vibration 
control devices and fit
tings
, when used, shall protect the components of the hydronic system from damage caused by 
expansion, contraction, transverse movement, angular deflection and vibration,
shall be 
rated for the temperatures 
and pressures of the systems in which the devices
are installed, and shall be compatible with the fluid and all materials 
provided
.
SECTION 
MC 
1203
JOINTS AND CONNECTIONS
1203.1 Approval. 
Joints and connections
, other than those contained in Section 1203 and conforming to the ASTM 
standards listed in Sec
tion 1203,
shall be of an approved type. Joints and connections shall be tight for the pressure 
of the hydronic system.
1203.1.1 Joints between different piping materials. 
Joints between different piping materials shall be 
rated for 
the temperatures and pr
essures of the systems in which the devices are installed and shall be compatible with the 
fluid and all materials provided. 
1203.
1.2 Joints between dissimilar metallic piping materials.
Joints between dissimilar metallic piping mate-
rials shall be provide
d to protect against galvanic corrosion. Such joints shall be 
made with 
dielectric fittings 
conforming to ANSI B16.39 or ASTM F 492, as applicable, shall be rated for the temperatures and pressures of 
the systems in which the devices are installed and shal
l be compatible with the fluid and all materials provided
.
Exception:
Dielectric fittings shall not be required for joints between dissimilar metal piping used within heat 
transfer appliances or equipment when such joints are provided by the appliance or e
quipment manufacturer, 
and such appliance or equipment is connected with isolation valves that are accessible.
1203.2 Preparation of pipe ends. 
Pipe shall be cut square, reamed and chamfered, and shall be free of burrs and 
obstructions. Pipe ends shall hav
e full
-
bore openings and shall not be undercut.
1203.3 Joint preparation and installation. 
Where required by Sections 1203.4 through 1203.14, the preparation and 
installation of brazed, mechanical, soldered, 
solvent
-
cemented
, threaded and welded joints shall comply with Sections 
1203.3.1 through 1203.3.8.
1203.3.1 Brazed joints.
All joints 
shall
be brazed with a 
brazing procedure developed and qualified in accordance 
with the ASME
Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications) or in accord-
ance with 
AWS 
B2.2 Standard for Brazing Procedure and Performance Qualifica
tion
.
1203.3.2 Mechanical joints. 
Mechanical joints shall be installed in accordance with the manufacturer’s instruc-
tions.
1203.3.3 Soldered joints. 
Joint surfaces shall be cleaned. A flux conforming to ASTM B 813 shall be applied. The 
joint shall be solde
red with a solder conforming to ASTM B 32.
1203.3.4 Solvent
-
cemented joints. 
Joint surfaces shall be clean and free of moisture. 
A
primer
, compatible with 
both the piping material and the cement
shall be applied to pipe
-
joint surfaces
, in accordance with t
he manufac-
turer’s requirements
. Joints shall be made while the cement is wet. Solvent cement conforming to the following 
standards shall be applied to all joint surfaces:
1.
ASTM D 2235 for ABS joints.
2.
ASTM F 493 for CPVC joints.
HYDRONIC PIPING
3.
ASTM D 2564 for PVC 
joints.
1203.3.5 Threaded joints. 
Threads shall conform to ASME B1.20.1. Schedule 80 or heavier plastic pipe shall be 
threaded with dies specifically designed for plastic pipe. Thread lubricant, pipe
-
joint compound or tape shall be 
applied on the male threads only and shall be 
compatible
f
or application on the piping material
and fluid
.
1203.3.6 Welded joints.
All joints shall be welded with a welding procedure developed and qualified in accord-
ance with the 
ASME Boiler and Pressure Vessel Code
, Section IX (Welding and Brazing Qualifications
) or in 
accordance with AWS B2.1 Specifications for Welding Procedure and Performance Qualification.
1203.3.7 Grooved and shouldered mechanical joints. 
Grooved and shouldered mechanical joints shall conform 
to the requirements of ASTM F 1476 and shall be i
nstalled in accordance with the manufacturer’s
instructions.
1203.3.8 Mechanically formed tee fittings. 
Mechanically extracted outlets shall have a height not less than three 
times the thickness of the branch tube wall.
1203.3.8.1 Full flow assurance. 
Bran
ch tubes shall not restrict the flow in the run tube. A dimple/depth stop 
shall be formed in the branch tube to ensure that penetration into the outlet is of the correct depth. For inspection 
purposes, a second dimple shall be placed
1
/
4
inch (6.4 mm) above the first dimple. Dimples shall be aligned 
with the tube run.
1203.3.8.2 Brazed joints. 
Mechanically formed tee fittings shall be brazed in accordance with Section 1203.3.1.
1203.4 ABS plastic pipe. 
Joints between ABS plastic pipe or f
ittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.5 Brass pipe. 
Joints between brass pipe or fittings shall be brazed, mechanical, threaded or welded joints con-
forming to Section 1203.3.
1203.6 Brass tubing. 
Joints bet
ween brass tubing or fittings shall be brazed, mechanical or soldered joints conforming 
to Section 1203.3.
1203.7 Copper or copper
-
alloy pipe. 
Joints between copper or copper
-
alloy pipe or fittings shall be brazed, mechan-
ical, soldered, threaded or welded 
joints conforming to Section 1203.3.
1203.8 Copper or copper
-
alloy tubing. 
Joints between copper or copper
-
alloy tubing or fittings shall be brazed, 
mechanical or soldered joints conforming to Section 1203.3, flared joints conforming to Section 1203.8.1
or
push
-
fit 
joints conforming to Section 1203.8.2.
1203.8.1 Flared joints. 
Flared joints shall be made by a tool designed for that operation.
1203.8.2 Push
-
fit joints. 
Push
-
fit joints shall be installed in accordance with the manufacturer’s instructions.
120
3.9 CPVC plastic pipe.   
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.10 Reserved.
1203.11 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints between cross
-
linked polyethyle
ne plastic tubing 
and fittings shall conform to Sections 1203.11.1 and 1203.11.2. Mechanical joints shall conform to Section 1203.3.
1203.11.1 Compression
-
type fittings. 
Where
compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings 
shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.11.2 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not less 
than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same 
water line.
1203.12 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded joints 
conforming to Section 1203.3.
1203.13 Steel pipe. 
Joints between steel pipe or fittings shall be mechanical
, threaded or welded 
joints 
conforming to 
Section 1203.3.
1203.14 Steel tubing. 
Joints between steel tubing or fittings shall be mechanical or welded joints conforming to Sec-
tion 1203.3.
HYDRONIC PIPING
1203.15 Polypropylene (PP) plastic. 
Joints between PP plastic pipe and fittings shall comp
ly with Sections 1203.15.1 
and 1203.15.2.
1203.15.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylene fittings, electro
-
fusion polypropylene fittings or by butt
fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1203.15.2 Mechanical and compression sleeve joints. 
Mechanical and compression sleeve joints shal
l be installed 
in accordance with the manufacturer’s instructions.
1203.16 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyethylene 
tubing and fittings shall conform to Sections 1203.16.1 and 1203.16.2. Mechani
cal joints shall conform to Section 
1203.3.
1203.16.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.16.2 PE
-
RT
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 mm) 
of a transition from such metal pipe to PE
-
RT pipe.
1203.17 Polyethylene/aluminum/polyethylene (PE
-
AL
-
PE) pressure pipe. 
Joints between polyethylene/alumi-
num/po
lyethylene pressure pipe and fittings shall conform to Sections 1203.17.1 and 1203.17.2. Mechanical joints 
shall comply with Section 1203.3.
1203.17.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
f
ittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.17.2 PE
-
AL
-
PE
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches (457.2 
mm) of a transition from such metal pipe to PE
-
AL
-
PE pipe.
1203.18 Cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene (PEX
-
AL
-
PEX) pressure pipe. 
Joints 
between cross
-
linked polyethylene/aluminum/cross
-
linked polyethylene pressure pipe and fittings shall conform to 
Sections 1203.18.1 and 1203.18.2. Mecha
nical joints shall comply with Section 1203.3.
1203.18.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, the 
fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1203.18.2 PEX
-
AL
-
PEX
-
to
-
metal connections. 
Solder joints in a metal pipe shall not occur within 18 inches 
(457.2 mm) of a transition from such metal pipe to PEX
-
AL
-
PEX pipe.
SECTION 
MC 
1204
PIPE INSULATION
1204.1 Insulation characteristics. 
Pipe insulation installed in buildings shall conform to the requirements of the 
New 
York City
Energy Conservation Code
,
shall be tested in accordance with ASTM E 84 or UL 723, using the specimen 
preparation and mounting p
rocedures of ASTM E 2231; and shall have a maximum flame spread index of 25 and a 
smoke
-
developed index not exceeding 450. Insulation installed in an air plenum shall comply with Section 602.2.1.
1204.2 Required thickness. 
Hydronic piping shall be insulate
d to the thickness required by the 
New York City
Energy 
Conservation Code.
SECTION 
MC 
1205
VALVES
1205.1 Where required. 
Shutoff valves shall be installed in hydronic piping systems in the locations indicated in 
Sections 1205.1.1 through 1205.1.6.
1205.1.1
Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
HYDRONIC PIPING
Exception: 
Shutoff valves shall not be required where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat 
exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1205.1.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of central utility 
systems, and district
heating and cooling 
systems.
1205.1.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1205.1.4 Pressure
-
reducing valves. 
Shutoff valves shall be installed on both sides of a pressure
-
reduc
ing valve.
1205.1.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a hydronic system such as pumps, air separators, 
metering devices and si
milar equipment.
1205.1.6 Expansion tanks.
Lockable shutoff
valves shall be installed at connections to 
all
expansion tanks.
Valves shall be locked in the open position.
1205.2 Reduced pressure. 
A pressure relief valve shall be installed on the 
low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system design. 
The valve shall be installed in accordance with Section 1006.
SECTION 
MC 
1206
PIPING INSTALLATION
1
206.1 General. 
Piping, valves, fittings and connections shall be installed in accordance with the conditions of ap-
proval.
1206.2 System drain down. 
Hydronic piping systems shall be designed and installed to permit the system to be 
drained. Where the system
drains to the plumbing drainage system, the installation shall conform to the requirements 
of the 
New York City
Plumbing Code.
Exception: 
The buried portions of systems embedded underground.
1206.3 Protection of potable water. 
The potable water system sha
ll be protected from backflow in accordance with 
the 
New York City
Plumbing Code.
1206.4 Pipe penetrations. 
Openings for pipe penetrations in walls, floors or ceilings shall be larger than the penetrat-
ing pipe. Openings through concrete or masonry building
elements shall be sleeved. The annular space surrounding 
pipe penetrations shall be protected in accordance with the 
New York City
Building Code.
1206.5 Clearance to combustibles. 
A pipe in a hydronic piping system in which the exterior temperature exceed
s 
250°F (
121.1
°C) shall have a minimum clearance of 1 inch (25.4 mm) to combustible materials.
1206.6 Contact with building material. 
A hydronic piping system shall not be in direct contact with building mate-
rials that cause the piping material to degrade 
or corrode, or that interfere with the operation of the system.
1206.7 Water hammer. 
The flow velocity of the hydronic piping system shall be controlled to reduce the possibility 
of water hammer. Where a quick
-
closing valve creates water hammer, an 
enginee
red
water
-
hammer arrestor shall be 
installed. The arrestor shall be located within a range as specified by the manufacturer of the quick
-
closing valve.
1206.8 Steam piping pitch. 
Steam piping shall be installed to drain to the boiler or the steam trap. Ste
am systems 
shall not have drip pockets that reduce the capacity of the steam piping.
1206.9 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains and stresses in the pipe. 
Provisions shall be made to protect piping from damag
e resulting from expansion, contraction and structural settle-
ment. Piping shall be installed so as to avoid structural stresses or strains within building components.
1206.9.1 Flood hazard. 
Piping located in flood hazard areas 
shall comply with Appendix G
of 
the 
New York City 
Building Code
.
HYDRONIC PIPING
1206.10 Pipe support. 
Pipe shall be supported in accordance with Section 305.
Seismic supports shall be provided 
where required by the 
New York City Building Code.
1206.11 Condensation. 
Provisions shall be made to prevent the formation of condensation on the exterior of piping.
SECTION 
MC 
1207
TRANSFER FLUID
1207.1 Flash point. 
The
flash point of transfer fluid in a hydronic piping system shall be not less than 50°F (10°C) 
above the maximum system operating temperature.
1207.2 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
SECTION 
MC 
1208
TESTS
1208.1 General. 
Hydronic piping systems 
other than ground
-
source heat pump loop systems 
shall be tested hydro-
statically at one and one
half times the system design 
operating 
pressure, but not less than 100 psi (689 kPa). The 
duration of each 
test shall be not less than
2 hours. Ground
-
source heat pump loop systems shall be tested in accord-
ance with Section 1210.10.
SECTION 
MC 
1209
EMBEDDED PIPING
1209.1 Materials. 
Embedded piping
shall be plastic pipe or tubing
, in accordance with Section 1202
,
rated at 100 psi 
(689.5 kPa) at 180°F (82.2°C).
1209.2 Pressurizing during installation. 
Piping to be embedded in concrete shall be pressure tested prior to pouring 
concrete. During pouring, the pipe shall be maintained at the proposed operating pressure
.
1209.3 Embedded joints. 
Joints of pipe or tubing that are embedded in a portion of the building, such as concrete or 
plaster, shall be thermally
-
fused.
1209.4 Not embedded related piping. 
Joints of other piping in cavities or running exposed shall be joi
ned in accord-
ance with manufacturer’s instructions and related sections of this code.
1209.5 Thermal barrier required. 
Radiant floor heating systems shall be provided with a thermal barrier in accord-
ance with Sections 1209.5.1 through 1209.5.4.
Exception: 
Insulation shall not be required in engineered systems where it can be demonstrated that the insulation 
will decrease the efficiency or have a negative effect on the installation.
1209.5.1 Slab
-
on
-
grade installation. 
Radiant piping utilized in slab
-
on
-
grad
e applications shall be provided with 
insulating materials installed beneath the piping having a minimum R
-
value of 5.
1209.5.2 Suspended floor installation. 
In suspended floor applications, insulation shall be installed in the joist 
bay cavity serving the
heating space above and shall consist of materials having a minimum R
-
value of 11.
1209.5.3 Thermal break required. 
A thermal break shall be provided consisting of asphalt expansion joint mate-
rials or similar insulating materials at a point where a heated
slab meets a foundation wall or other conductive slab.
1209.5.4 Thermal barrier material marking. 
Insulating materials utilized in thermal barriers shall be installed 
such that the manufacturer’s R
-
value mark is readily observable upon inspection.
SECTION
MC 
1210
PLASTIC PIPE GROUND
-
SOURCE HEAT PUMP LOOP SYSTEMS
HYDRONIC PIPING
1210.1 Ground
-
source heat pump
-
loop water piping. 
Ground
-
source heat pump ground
-
loop piping and tubing 
material for water
-
based systems shall conform to the standards cited in this section.
1210.2
Used materials. 
Reused pipe, fittings, valves, and other materials shall not be permitted in ground
-
source heat 
pump loop systems.
1210.3 Material rating. 
Pipe and tubing shall be rated for the operating temperature and pressure of the ground
-
source heat 
pump loop system. Fittings shall be suitable for the pressure applications and recommended by the man-
ufacturer for installation with the pipe and tubing material installed. Where used underground, materials shall be suit-
able for burial.
1210.4 Piping and t
ubing materials standards. 
Ground
-
source heat pump ground
-
loop pipe and tubing shall con-
form to the standards listed in Table 1210.4.
TABLE 1210.4
GROUND
-
SOURCE LOOP PIPE
MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl chloride 
(CPVC)
ASTM D 
2846; ASTM F 
441; ASTM F 442
Cross
-
linked polyethylene (PEX)
ASTM F 876; ASTM F 877; 
CSA B137.5
Polyethylene/aluminum/polyethylen
e (PE
-
AL
-
PE) pressure pipe
ASTM F 1282; CSA B137.9
High
-
density polyethylene (HDPE)
ASTM D 2737; ASTM D 
3035; ASTM F 
714; AWWA 
C901; CSA B137.1; CSA 
C448; NSF 358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl chloride (PVC)
ASTM D 1785; ASTM D 
2241
Raised temperature polyethylene 
(PE
-
RT)
ASTM F 2623
1210.5 Fittings. 
Ground
-
source heat pump pipe fittings shall conform to the standards listed in Table 1210.5 and, if 
installed underground, shall be suitable for burial. 
TABLE 1210.5
GROUND
-
SOURCE LOOP PIPE FITTINGS
PIPE MATERIAL
STANDARD (see Chapter 15)
Chlorinated polyvinyl 
chloride (CPVC)
ASTM D 2846; ASTM F 437; ASTM F 
438; ASTM F 439; CSA B137.6
Cross
-
linked 
polyethylene (PEX)
ASTM F 877; ASTM F 1807; ASTM F 
1960; ASTM F 2080; ASTM F 2159; 
ASTM F 2434; CSA B137.5
Polyethylene/aluminum/
polyethylene (PE
-
AL
-
PE)
ASTM F 1282; ASTM F 2434; CSA 
B137.9
HYDRONIC PIPING
High Density 
Polyethylene (HDPE)
ASTM D 2683; ASTM D 3261; ASTM 
F 1055; CSA B137.1; CSA C448; NSF 
358
-
1
Polypropylene (PP
-
R)
ASTM F 2389; CSA B137.11
Polyvinyl 
chloride 
(PVC)
ASTM D 2464; ASTM D 2466; ASTM 
D 2467; CSA B137.2; CSA B137.3
Raised temperature 
polyethylene (PE
-
RT)
ASTM D 3261; ASTM F 1807; ASTM 
F 2159; CSA B137.1
1210.6 Joints. 
Joints and connections, 
other than those covered by Section 1210 and co
nforming to the ASTM stand-
ards listed therein,
shall be of an approved type. Joints and connections shall be tight for the pressure of the ground
-
source loop system. Joints used underground shall be in accordance with manufacturer’s instructions for buried
appli-
cations.
1210.6.1 Joints between different piping materials. 
Joints between different piping materials shall be made with 
transition fittings compatible with both materials and the fluid contained within the system. Transition fittings must 
be used i
n accordance with manufacturer’s instructions.
1210.6.1.1 Plastic
-
to
-
metal connections. 
Soldering on the metal portion of the system shall be performed not 
less than 18 inches (457.2 mm) from a plastic
-
to
-
metal adapter in the same water line.
1210.6.2 Prep
aration of pipe ends. 
Pipe shall be cut square, be reamed, and be free of burrs and obstructions. 
CPVC, PE, and PVC pipe shall be chamfered. Pipe ends shall have full
-
bore openings and shall not be undercut.
1210.6.3 Joint preparation and installation. 
Whe
re required by Sections 1210.6.4 through 1210.6.6, the prepa-
ration and installation of mechanical and thermoplastic
-
welded joints shall comply with Sections 1210.6.3.1 and 
1210.6.3.2.
1210.6.3.1 Mechanical joints. 
Mechanical joints shall be installed in ac
cordance with the manufacturer’s in-
structions.
1210.6.3.2 Thermoplastic
-
welded joints. 
Joint surfaces for thermoplastic
-
welded joints shall be cleaned by a 
procedure in accordance with the manufacturer’s instructions. Joints shall be welded in accordance w
ith the 
manufacturer’s instructions.
1210.6.4 CPVC plastic pipe. 
Joints between CPVC plastic pipe or fittings shall be solvent
-
cemented or threaded 
joints complying with Section 1203.3.
‡‡‡
1210.6.5 Cross
-
linked polyethylene (PEX) plastic tubing. 
Joints bet
ween cross
-
linked polyethylene plastic 
tubing and fittings shall comply with Section 1210.6.5.1. Mechanical joints shall comply with Section 1210.6.3.
1210.6.5.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
r
ings, 
the fittings shall be installed without omitting the inserts and ferrules or O
-
rings.
1210.6.6 Polyethylene plastic pipe and tubing for ground
-
source heat pump loop systems. 
Joints between 
polyethylene plastic pipe and tubing or fittings for 
ground
-
source heat pump loop systems shall be heat fusion 
joints complying with Section 1210.6.6.1, electrofusion joints complying with Section 1210.6.6.2, or stab
-
type 
insertion joints complying with Section 1210.6.6.3.
1210.6.6.1 Heat
-
fusion joints. 
Joints shall be of the socket
-
fusion, saddle
-
fusion or butt
-
fusion type, joined in 
accordance with ASTM D 2657. Joint surfaces shall be clean and free from moisture. Joint surfaces shall be 
heated to melt temperatures and joi
ned. The joint shall be undisturbed until cool. Fittings shall be manufactured 
in accordance with ASTM D 2683 or ASTM D 3261.
1210.6.6.2 Electrofusion joints. 
Joints shall be of the electrofusion type. Joint surfaces shall be clean and free 
from moisture, 
and scoured to expose virgin resin. Joint surfaces shall be heated to melt temperatures for the 
HYDRONIC PIPING
period of time specified by the manufacturer. The joint shall be undisturbed until cool. Fittings shall be manu-
factured in accordance with ASTM F 1055.
1210.6.6
.3 Stab
-
type insert fittings. 
Joint surfaces shall be clean and free from moisture. Pipe ends shall be 
chamfered and inserted into the fittings to full depth. Fittings shall be manufactured in accordance with ASTM 
F 1924.
1210.6.7 Polypropylene (PP) plasti
c. 
Joints between PP plastic pipe and fittings shall comply with Sections 
1210.6.7.1 and 1210.6.7.2.
1210.6.7.1 Heat
-
fusion joints. 
Heat
-
fusion joints for polypropylene (PP) pipe and tubing joints shall be installed 
with socket
-
type heat
-
fused polypropylen
e fittings, electrofusion polypropylene fittings or by butt fusion. Joint 
surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in 
accordance with ASTM F 2389.
1210.6.7.2 Mechanical and compression 
sleeve joints. 
Mechanical and compression sleeve joints shall be 
installed in accordance with the manufacturer’s instructions.
1210.6.8 Raised temperature polyethylene (PE
-
RT) plastic tubing. 
Joints between raised temperature polyeth-
ylene tubing and fittin
gs shall comply with Sections 1210.6.8.1 and 1210.6.8.2. Mechanical joints shall comply 
with Section 1210.6.3.
1210.6.8.1 Compression
-
type fittings. 
Where compression
-
type fittings include inserts and ferrules or O
-
rings, 
the fittings shall be installed wi
thout omitting the inserts and ferrules or O
-
rings.
1210.6.9 PVC plastic pipe. 
Joints between PVC plastic pipe and fittings shall be solvent
-
cemented or threaded 
joints comply with Section 1203.3.
1210.7 Shutoff valves. 
Shutoff valves shall be installed in
ground
-
source loop piping systems in the locations indi-
cated in Sections 1210.7.1 through 1210.7.7.
1210.7.1 Heat exchangers. 
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
Exception: 
Shutoff valves shall not be requi
red where heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer’s boiler and heat exchanger packaged unit and are capable of being isolated from the 
hydronic system by the supply and return valves required by Section 1005.1.
1210
.7.2 Central systems. 
Shutoff valves shall be installed on the building supply and return of a central utility 
system.
1210.7.3 Pressure vessels. 
Shutoff valves shall be installed on the connection to any pressure vessel.
1210.7.4 Pressure
-
reducing valves.
Shutoff valves shall be installed on both sides of a pressure
-
reducing valve.
1210.7.5 Equipment and appliances. 
Shutoff valves shall be installed on connections to mechanical equipment 
and appliances. This requirement does not apply to components of a gr
ound
-
source loop system such as pumps, air 
separators, metering devices, and similar equipment.
1210.7.6 Expansion tanks. 
Shutoff valves shall be installed at connections to nondiaphragm
-
type expansion tanks.
1210.7.7 Reduced pressure. 
A pressure relief va
lve shall be installed on the low
-
pressure side of a hydronic piping 
system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system 
design. The valve shall be installed in accordance with Section 1006.
1210.8 
Installation. 
Piping, valves, fittings, and connections shall be installed in accordance with the 
conditions of approval.
1210.8.1 Protection of potable water. 
Where ground
-
source heat pump ground
-
loop systems have a connection 
to a potable water supply, t
he potable water system shall be protected from backflow in accordance with the 
New 
York City Plumbing Code
.
1210.8.2 Pipe penetrations. 
Openings for pipe penetrations in walls, floors and ceilings shall be larger than the 
penetrating pipe. Openings throug
h concrete or masonry building elements shall be sleeved. The annular space 
surrounding pipe penetrations shall be protected in accordance with the 
New York City Building Code
.
HYDRONIC PIPING
1210.8.3 Clearance from combustibles. 
A pipe in a ground
-
source heat pump pipin
g system having an exterior 
surface temperature exceeding 250°F (121.1°C) shall have a minimum clearance of 1 inch (25.4 mm) from com-
bustible materials.
1210.8.4 Contact with building material. 
A ground
-
source heat pump ground
-
loop piping system shall not 
be in 
direct contact with building materials that cause the piping or fitting material to degrade or corrode, or that interfere 
with the operation of the system.
1210.8.5 Strains and stresses. 
Piping shall be installed so as to prevent detrimental strains 
and stresses in the pipe. 
Provisions shall be made to protect piping from damage resulting from expansion, contraction and structural set-
tlement. Piping shall be installed so as to avoid structural stresses or strains within building components.
1210.8.6 F
lood hazard. 
Piping located in a flood hazard area shall be capable of resisting hydrostatic and hydro-
dynamic loads and stresses, including the effects of buoyancy, during the occurrence of flooding to the design flood 
elevation.
1210.8.7 Pipe support. 
Pip
e shall be supported in accordance with Section 305.
1210.8.8 Velocities. 
Ground
-
source heat pump ground
-
loop systems shall be designed so that the flow velocities 
do not exceed the maximum flow velocity recommended by the pipe and fittings 
manufacturer and shall be con-
trolled to reduce the possibility of water hammer.
1210.8.9 Labeling and marking. 
Ground
-
source heat pump ground
-
loop system piping shall be marked with tape, 
metal tags or other method where it enters a building indicating “GR
OUND
-
SOURCE HEAT PUMP LOOP SYS-
TEM.” The marking shall indicate any antifreeze used in the system by name and concentration.
1210.8.10 Chemical compatibility. 
Antifreeze and other materials used in the system shall be chemically compat-
ible with the 
pipe, tubing, fittings, and mechanical systems.
1210.9 Makeup water. 
The transfer fluid shall be compatible with the makeup water supplied to the system.
1210.10 Tests. 
Before connection header trenches are backfilled, the assembled loop system shall be pr
essure tested 
with water at 100 psi (689.5 kPa) for 15 minutes, in which time there shall not be observed leaks. Flow and pressure 
loss testing shall be performed and the actual flow rates and pressure drops shall be compared to the calculated design 
value
s. If actual flow rate or pressure drop values differ from calculated design values by more than 10 percent, the 
cause shall be identified and corrective action taken.
1210.11 Embedded piping. 
Ground
-
source heat pump ground
-
loop piping to be embedded in co
ncrete shall be pres-
sure tested prior to pouring concrete. During pouring, the pipe shall be maintained at the proposed operating pressure. 
Embedded piping shall comply with Section 1209.
SECTION MC 1211
HIGH
-
PRESSURE STEAM AND
HIGH TEMPERATURE HOT WATER P
IPING SYSTEMS
1211.1 Scope.
The provisions of this section shall apply to high
-
pressure steam piping system, which is defined as a 
system operating at a steam pressure of more than 15 psi (103.4 kPa), and high temperature water intended for 
operation at pr
essures in excess of 160 psi (1103.2 kPa) and temperatures in excess of 250°F (121.1°C). For purposes 
of this section, loops, bends or offsets of the piping shall not be considered expansion joints.
1211.2 New systems.
For purposes of this section, the rep
lacement of existing steam piping systems, the installation 
of a new system in existing buildings, as well as installations in buildings hereafter constructed, shall be considered 
to be new high
-
pressure steam piping systems. The following requirements are
applicable:
1211.2.1 Design.
The design of new steam piping systems shall be conducted as follows:
1.
The system shall be designed by an engineer. An application and plans shall be filed and the approval of the 
department obtained. The plans and applicati
on shall contain, but not be limited to, the following information:
1.1.
Size and location of all steam piping.
HYDRONIC PIPING
1.2.
The operating pressures and temperatures.
1.3.
The location, type, specifications and details of all expansion joints.
1.4.
The design, siz
e, material and location of all anchors, guides and auxiliary steel, and the stresses thereon.
2.
Systems using utility street steam shall be designed for a pressure of 200 psig (1379 kPa) and 413°F (211.7°C) 
up to and including the steam pressure reducing
valve or valves which reduce the pressure of 90 psig (620.5 
kPa) or below. For steam pressures between 90 psig (620.5 kPa) and 16 psig (110.3 kPa), the system shall be 
designed for 125 psig (861.8 kPa).
3.
Steam distribution systems utilizing pressure red
ucing valves.
3.1.
Safety Shutoff Valves (SSO) to protect downstream piping from overpressure shall be allowed in lieu of 
a safety relief valve vented to the outdoors as required by Section 1006.6.
3.2.
SSO shall be designed to automatically close at or be
low the design pressure of the downstream piping 
system that is being protected, to provide positive shutoff against full upstream pressure. Manual reset 
shall be required to reopen the SSO.
3.3.
SSO shall be designed in accordance with the Steam Distribut
ion Utility System requirements of the 
utility company having jurisdiction and ASME B31.1.
4.
Bellows expansion joints shall not be utilized on high pressure steam piping.
Exception: 
Bellows expansion joints shall be permitted for final connection to equip
ment where readily 
accessible for inspection and service and within Mechanical Equipment Rooms.
1211.2.2 Installation.
The installation of new steam piping systems shall be conducted as follows:
1.
Installations, including any welding, shall be subject to 
special inspection.
2.
Welders shall be qualified for all required pipe sizes, wall thicknesses and positions in accordance with the 
ASME
Boiler and Pressure Vessel Code,
Section IX. Requalification is required every five years or sooner 
if the commissione
r has a specific reason to doubt a welder’s ability to make acceptable welds.
3.
Welder qualification testing shall be performed by an approved agency listed with the department, and the 
inspector witnessing the test shall be an authorized AWS Certified We
lding Inspector. If the testing is by 
radiography, the test specimen shall be evaluated by personnel having a minimum radiography qualification 
of Level II in accordance with the ASNT, Document No. SNT
-
TC
-
1A, Supplement A. A successful radio-
graphic test of
a production weld made within the 6 months prior to requalification may be considered as an 
acceptable requalification test.
4.
Copies of the certified welder qualification reports shall be maintained by the responsible welding agency 
and the company perf
orming the welding, and shall be made available upon request to the department.
5.
No reports from any welding inspection agency shall be accepted unless such agency has first requested and 
obtained approval from the department in accordance with rules of 
the department.
6.
Pipe welding shall conform to the following:
6.1.
All piping over 2 inches (
50.8
mm) shall be butt
-
welded. Piping 2 inches (50.8 mm) and under may be 
socket
-
welded or threaded, providing Schedule 80 piping is utilized.
6.2.
Threaded piping may continue to be used for existing construction in size of 6 inches (
152.4
mm) and 
under.
6.3.
Where welding is not feasible, the commissioner may allow an acceptable alternative.
7.
Radiographic examination, when required, shall be performed on butt
-
welds in accordance with ASME 
B31.1 based on the piping system design pressure and shall be as foll
ows:
Piping System Design Pressure
Percentage
90 psig (620.5 kPa) or below
Not Required
HYDRONIC PIPING
91 psig (627.4 kPa) to
150 psig (1034.2 kPa)
10 at Random
Over 150 psig (1034.2 kPa)
100
However, if, in the opinion of the engineer responsible for special inspection, radiographic examination is not 
required for piping at pressure between 90 psig (620.5 kPa) and 150 psig (1034.2 kPa), the engineer shall so specify 
in writing, and the final r
eport on the installation may omit the foregoing, and be predicated on all of the other 
requirements noted in this section, and a hydrostatic test.
1211.2.3 Testing.
Hydrostatic testing shall be conducted on the completed installation at 150 percent of the
design 
pressure for all piping pressure. Where the changes in an existing steam system involve less than 30 percent of 
the piping in the system, the testing may be in accordance with ASME B31.1.
1211.2.4 Relocation.
The commissioner, where deemed necessar
y, shall require the replacement or relocation of 
any expansion joints, guides or anchors. The commissioner shall cause the expansion joints in potentially hazard-
ous locations, such as those that are located adjacent to tenant occupied spaces, to be reloca
ted, unless means exist 
or are provided for eliminating the hazard.
1211.3 Existing systems.
Existing steam piping systems shall be in accordance with Sections 1211.3.1 through 
1211.3.2. Upon the completion of a new high
-
pressure steam piping system and de
partment approval of same, the 
rules relating to maintenance requirements and the keeping of records for existing high
-
pressure steam piping sys-
tems shall apply.
1211.3.1 Maintenance inspections.
Expansion joints, anchorage and guides shall be inspected as
follows:
1.
Expansion joints shall be visually inspected monthly.
2.
The anchorage and guides shall be visually inspected annually. Exposure of the structural attachments to the 
buildings of the anchorages or guides shall not be required.
3.
A record of s
uch inspections shall be kept by the person in charge of the mechanical equipment of the building 
or other qualified person designated by the owner and acceptable to the commissioner. The records shall be 
available at the premises and subject to inspection
by the commissioner.
1211.3.2 Work approval.
No joint, anchorage or guides shall be repaired, replaced or relocated without a work 
permit issued by the department. The application for the permit shall contain all pertinent information and shall 
be filed by an engineer knowledgeable as to high
-
pressur
e steam piping systems. The engineer shall be responsible 
for the special inspection of the proposed work in accordance with the approved application. This provision shall 
not apply to the repacking of a slip or ball joint; however, records of such repacki
ng shall be kept in the inspection 
records as provided in Section 1211.3.1, Item 3. When, in the opinion of the engineer, the requirement for prior 
department approval would create an imminent health or safety hazard, the engineer may permit the work to 
pr
oceed without prior approval. In such cases, the engineer shall, prior to the repair, replacement or relocation, 
notify by telephone the borough commissioner of the borough in which the building is located; and, if the emer-
gency occurs at other than normal
working hours, he or she shall notify the department in a manner prescribed by 
the commissioner. This shall be followed by the filing of the application for department approval as specified in 
Section 28
-
105.4.1 of the 
Administrative Code
.