CHAPTER 9 VENTS SECTION PC 901 GENERAL 901.1 Scope. The provisions of this chapter shall govern the materials, design, construction and installation of vent systems except for vent systems for methane and radon which shall be governed by this section . 901.1.1 Methane and radon venting. The design and mater ials used in the installation of the methane and radon vent systems shall be approved by the commissioner and shall comply with all applicable rules of the Fire De- partment. 901.2 Trap seal protection. The plumbing system shall be provided with a system of vent piping that will permit the admission or emission of air so that the seal of any fixture trap shall not be subjected to a pressure differential of more than 1 inch of water column (249 Pa). 901.2.1 Venting required. Traps and trapped fixtures shall be vented in accordance with one of the venting meth- ods specified in this chapter. 901.3 Chemical waste vent systems. The vent system for a chemical waste system shall be independent of the sanitary vent system and shall terminate separately through the roof to the outdoors . 901.4 Use limitations. The plumbing vent system shall not be utilized for purposes other than the venting of the plumbing system. 901.5 Tests. The vent system shall be tested in accordance with Section 312. 901.6 Engineered systems. Engin eered venting systems shall conform to the provisions of Section 919 . SECTION PC 902 MATERIALS 902.1 Vents. The materials and methods utilized for the construction and installation of venting systems shall comply with the applicable provisions of Section 7 02. 902.2 Sheet copper. Sheet copper for vent pipe flashings shall conform to ASTM B 152 and shall weigh not less than 8 ounces per square foot (2.5 kg/m 2 ). 902.3 Sheet lead. Sheet lead for vent pipe flashings shall weigh not less than 3 pounds per square foot (15 kg/m 2 ) for field - constructed flashings and not less than 2 1 / 2 pounds per square foot (12 kg/m 2 ) for prefabricated flashings. SECTION PC 903 VENT TERMINALS 903.1 Roof extension. Open vent pipes that extend through a roof shall be terminated not less than 24 inches (610 mm) above the roof. Where a roof is to be used for assembly or as a promenade, observation deck, sun bathing deck or similar purposes, open vent pipes shall terminate not less than 7 feet (2134 mm) above the roof. Ap proved vandal - resistant vent caps may be used. 903.2 Frost closure. Vent extensions through a roof or wall shall be not less than 4 inches (102 mm) in diameter. Any increase in the size of the vent shall be made not less than 1 foot (305 mm) inside the the rmal envelope of the building. 903.3 Flashings. The juncture of each vent pipe with the roof line shall be made water tight by an approved flashing. 903.4 Prohibited use. A vent terminal shall not be used for any purpose other than a vent terminal. 903.5 Location of vent terminal. Locations of vent terminals shall comply with Sections 903.5.1 and 903.5.2. VENTS 9 - 2 2022 NEW YORK CITY PLUMBING CODE 903.5.1 New vent terminals. An open vent terminal from a drainage system of the new or altered building shall not be located directly beneath any door, o perable window, or other air intake opening of the building or of an adjacent building, and any such vent terminal shall not be within 10 feet (3048 mm) horizontally of such an opening unless it is at least 3 feet (914 mm) above the top of such opening. Wh en the consent of the owner of an adjoining taller build - ing is obtained, the owner of the new or altered building shall be permitted to carry the new vent stack, with adequate support, to a level above the higher existing roof. 903.5.2 New openings. A doo r, operable window, or other air intake opening of the new or altered building shall not be located within 10 feet (3048 mm) horizontally from an open vent terminal from a drainage system of an existing adjacent building unless the existing terminal is at least 3 feet (914 mm) above such opening. Whenever necessary, the owner of the new building shall at his or her own expense, and with approval of the adjoining owner, offset the vent stack of the adjacent existing building to a distance of 10 feet (3048 mm ) or more from such openings, or shall extend such vent stack to a height of at least 3 feet (924 mm) above the topmost opening. 903.6 Reserved. 903.7 Reserved. SECTION PC 904 OUTDOOR VENT EXTENSIONS 904 .1 Required vent extension. The vent system serving each building drain shall have not less than one vent pipe that extends to the outdoors. 904. 1.1 Installation. The required vent shall be a dry vent that connects to the building drain or an extension of a drain that connects to the building drain. Such vent shall not be an island fixture vent as allowed by Section 916. 904.1.2 Size. The required vent shall be sized in accordance with Section 906.2 based on the required size of the building drain. 904.2 Vent stack required. A vent stack shall be required for every drainage stack that has three branch intervals or more . 904.3 Vent termination. Vent stacks or stack vents shall terminate outdoors above the roof or to the stack vent portion of the soil or waste stack, at least 6 inches (152 mm) above the flood level of the highest fixture connection discharging into the soil or waste stack. 904.4 Vent connection at base. Vent stacks shall connect to the base of the drainage stack. The vent stack shall co nnect at or below the lowest horizontal branch. Where the vent stack connects to the building drain, the connection shall be located downstream of the drainage stack and within a distance of 10 times the diameter of the drainage stack. 904.5 Vent headers. Stack vents and vent stacks connected into a common vent header at the top of the stacks and extending to the open air above the roof at one point shall be sized in accordance with the requirements of Section 906.1, but shall not be smaller than the smalle st stack vent . The number of fixture units shall be the sum of all fixture units on all stacks connected thereto, and the developed length shall be the longest vent length from the intersection at the base of the most distant stack to the vent terminal in the open air, as a direct extension of one stack. 904.6 Sub - stack connections. Where it is desired to terminate stacks at a point below the roof terminus of the main vent stack, the sub - stack may connect to the main vent stack provided the portion of the m ain vent stack above the connection is sized for the total fixture unit load connected thereto, and for the maximum developed length of the stack or sub - stack. SECTION PC 905 VENT CONNECTIONS AND GRADES 905.1 Connection. Individual , branch and circuit vents shall connect to a vent stack, stack vent, or extend to the open air above the roof . VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 3 905.2 Grade. Vent and branch vent pipes shall be so graded and connected as to drain back to the drainage pipe by gravity. 905.3 Vent connection to drainage system. Every dry vent connecting to a horizontal drain shall connect above the centerline of the horizontal drain pipe. 905.4 Reserved. 905.5 Height above fixtures. A connection between a vent pipe and a vent stack or stack vent shall be made at not less than 6 inches (152 mm) above the flood level rim of the highest fixture served by the vent. Horizontal vent pipes forming branch vents, relief vents or loop vents shall be located not less than 6 inches (152 mm) above the flood level rim of the highest fix ture served. 905.6 Vent for future fixtures. Where the drainage piping has been roughed - in for future fixtures, a rough - in con- nection for a vent shall be installed. The vent size shall be not less than one - half the diameter of the rough - in drain to be serv ed. The vent rough - in shall connect to the vent system, or shall be vented by other means as provided for in this chapter. The connection shall be identified to indicate that it is a vent. SECTION PC 906 VENT PIPE SIZING 906.1 Size of stack vents and vent stacks. The minimum required diameter of stack vents and vent stacks shall be determined from the developed length and the total of drainage fixture units connected thereto in accordance with Table 906.1, but in no case shall the diameter be less than one - half the diameter of the drain served or less than 1 1 / 4 inches (32 mm). TABLE 906.1 SIZE AND DEVELOPED LENGTH OF STACK VENTS AND VENT STACKS DIAMETER OF SOIL OR WASTE STACK (inches) TOTAL FIXTURE UNITS BEING VENTED (dfu) MAXIMUM DEVELOPED LENGTH OF VENT (f eet) a DIAMETER OF VENT (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 5 6 8 10 12 1 1 / 4 2 30 — — — — — — — — — — 1 1 / 2 8 50 150 1 1 / 2 10 30 100 2 12 — 75 200 — — — — — — — — 2 20 30 50 150 — 2 1 / 2 42 26 30 100 300 3 10 — 42 150 360 1,040 — — — — — — 3 21 32 110 270 810 3 53 27 94 230 680 3 102 — 25 86 210 620 — — — — — — 4 43 — 35 85 250 980 4 140 — 27 65 200 750 4 320 — — 23 55 170 640 — — — — —STACK VENTS AND VENT STACKS DIAMETER OF SOIL OR WASTE STACK (inches) TOTAL FIXTURE UNITS BEING VENTED (dfu) MAXIMUM DEVELOPED LENGTH OF VENT (f eet) a DIAMETER OF VENT (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 5 6 8 10 12 1 1 / 4 2 30 — — — — — — — — — — 1 1 / 2 8 50 150 1 1 / 2 10 30 100 2 12 — 75 200 — — — — — — — — 2 20 30 50 150 — 2 1 / 2 42 26 30 100 300 3 10 — 42 150 360 1,040 — — — — — — 3 21 32 110 270 810 3 53 27 94 230 680 3 102 — 25 86 210 620 — — — — — — 4 43 — 35 85 250 980 4 140 — 27 65 200 750 4 320 — — 23 55 170 640 — — — — —STACK VENTS AND VENT STACKS DIAMETER OF SOIL OR WASTE STACK (inches) TOTAL FIXTURE UNITS BEING VENTED (dfu) MAXIMUM DEVELOPED LENGTH OF VENT (f eet) a DIAMETER OF VENT (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 5 6 8 10 12 1 1 / 4 2 30 — — — — — — — — — — 1 1 / 2 8 50 150 1 1 / 2 10 30 100 2 12 — 75 200 — — — — — — — — 2 20 30 50 150 — 2 1 / 2 42 26 30 100 300 3 10 — 42 150 360 1,040 — — — — — — 3 21 32 110 270 810 3 53 27 94 230 680 3 102 — 25 86 210 620 — — — — — — 4 43 — 35 85 250 980 4 140 — 27 65 200 750 4 320 — — 23 55 170 640 — — — — — VENTS 9 - 4 2022 NEW YORK CITY PLUMBING CODE 4 540 21 50 150 580 — 5 190 28 82 320 990 5 490 — — — 21 63 250 760 — — — — 5 940 18 53 210 670 5 1,400 16 49 190 590 6 500 — — — — 33 130 400 1,000 — — — 6 1,100 — 26 100 310 780 6 2,000 — 22 84 260 660 6 2,900 — — — — 20 77 240 600 — — — 8 1,800 — 31 95 240 940 8 3,400 — 24 73 190 729 8 5,600 — — — — — 20 62 160 610 — — 8 7,600 18 56 140 560 — 10 4,000 — 31 78 310 960 10 7,200 — — — — — — 24 60 240 740 — 10 11,000 20 51 200 630 10 15,000 18 46 180 571 12 7,300 — — — — — — — 31 120 380 940 12 13,000 — 24 94 300 720 12 20,000 — 20 79 250 610 12 26,000 — — — — — — — 18 72 230 500 15 15,000 — 40 130 310 15 25,000 — 31 96 240 15 38,000 — — — — — — — — 26 81 200 15 50,000 24 74 180 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm. a. The developed length shall be measured from the vent connection to the open air. 906.2 Vents other than stack vents or vent stacks. The diameter of individual vents, branch vents, circuit vents and relief vents shall be at least one - half the required diameter of the drain served. The required size of the drain shall be determined in accordance with Table 710.1(2). Vent pipes shall not be less than 1 1 / 4 inches (32 mm) in diameter. Vents shall be sized in accordance with Table 906.1 utilizing the drainage fixture units and the corresponding CHAPTER 9 VENTS SECTION PC 901 GENERAL 901.1 Scope. The provisions of this chapter shall govern the materials, design, construction and installation of vent systems except for vent systems for methane and radon which shall be governed by this section . 901.1.1 Methane and radon venting. The design and mater ials used in the installation of the methane and radon vent systems shall be approved by the commissioner and shall comply with all applicable rules of the Fire De- partment. 901.2 Trap seal protection. The plumbing system shall be provided with a system of vent piping that will permit the admission or emission of air so that the seal of any fixture trap shall not be subjected to a pressure differential of more than 1 inch of water column (249 Pa). 901.2.1 Venting required. Traps and trapped fixtures shall be vented in accordance with one of the venting meth- ods specified in this chapter. 901.3 Chemical waste vent systems. The vent system for a chemical waste system shall be independent of the sanitary vent system and shall terminate separately through the roof to the outdoors . 901.4 Use limitations. The plumbing vent system shall not be utilized for purposes other than the venting of the plumbing system. 901.5 Tests. The vent system shall be tested in accordance with Section 312. 901.6 Engineered systems. Engin eered venting systems shall conform to the provisions of Section 919 . SECTION PC 902 MATERIALS 902.1 Vents. The materials and methods utilized for the construction and installation of venting systems shall comply with the applicable provisions of Section 7 02. 902.2 Sheet copper. Sheet copper for vent pipe flashings shall conform to ASTM B 152 and shall weigh not less than 8 ounces per square foot (2.5 kg/m 2 ). 902.3 Sheet lead. Sheet lead for vent pipe flashings shall weigh not less than 3 pounds per square foot (15 kg/m 2 ) for field - constructed flashings and not less than 2 1 / 2 pounds per square foot (12 kg/m 2 ) for prefabricated flashings. SECTION PC 903 VENT TERMINALS 903.1 Roof extension. Open vent pipes that extend through a roof shall be terminated not less than 24 inches (610 mm) above the roof. Where a roof is to be used for assembly or as a promenade, observation deck, sun bathing deck or similar purposes, open vent pipes shall terminate not less than 7 feet (2134 mm) above the roof. Ap proved vandal - resistant vent caps may be used. 903.2 Frost closure. Vent extensions through a roof or wall shall be not less than 4 inches (102 mm) in diameter. Any increase in the size of the vent shall be made not less than 1 foot (305 mm) inside the the rmal envelope of the building. 903.3 Flashings. The juncture of each vent pipe with the roof line shall be made water tight by an approved flashing. 903.4 Prohibited use. A vent terminal shall not be used for any purpose other than a vent terminal. 903.5 Location of vent terminal. Locations of vent terminals shall comply with Sections 903.5.1 and 903.5.2. VENTS 9 - 2 2022 NEW YORK CITY PLUMBING CODE 903.5.1 New vent terminals. An open vent terminal from a drainage system of the new or altered building shall not be located directly beneath any door, o perable window, or other air intake opening of the building or of an adjacent building, and any such vent terminal shall not be within 10 feet (3048 mm) horizontally of such an opening unless it is at least 3 feet (914 mm) above the top of such opening. Wh en the consent of the owner of an adjoining taller build - ing is obtained, the owner of the new or altered building shall be permitted to carry the new vent stack, with adequate support, to a level above the higher existing roof. 903.5.2 New openings. A doo r, operable window, or other air intake opening of the new or altered building shall not be located within 10 feet (3048 mm) horizontally from an open vent terminal from a drainage system of an existing adjacent building unless the existing terminal is at least 3 feet (914 mm) above such opening. Whenever necessary, the owner of the new building shall at his or her own expense, and with approval of the adjoining owner, offset the vent stack of the adjacent existing building to a distance of 10 feet (3048 mm ) or more from such openings, or shall extend such vent stack to a height of at least 3 feet (924 mm) above the topmost opening. 903.6 Reserved. 903.7 Reserved. SECTION PC 904 OUTDOOR VENT EXTENSIONS 904 .1 Required vent extension. The vent system serving each building drain shall have not less than one vent pipe that extends to the outdoors. 904. 1.1 Installation. The required vent shall be a dry vent that connects to the building drain or an extension of a drain that connects to the building drain. Such vent shall not be an island fixture vent as allowed by Section 916. 904.1.2 Size. The required vent shall be sized in accordance with Section 906.2 based on the required size of the building drain. 904.2 Vent stack required. A vent stack shall be required for every drainage stack that has three branch intervals or more . 904.3 Vent termination. Vent stacks or stack vents shall terminate outdoors above the roof or to the stack vent portion of the soil or waste stack, at least 6 inches (152 mm) above the flood level of the highest fixture connection discharging into the soil or waste stack. 904.4 Vent connection at base. Vent stacks shall connect to the base of the drainage stack. The vent stack shall co nnect at or below the lowest horizontal branch. Where the vent stack connects to the building drain, the connection shall be located downstream of the drainage stack and within a distance of 10 times the diameter of the drainage stack. 904.5 Vent headers. Stack vents and vent stacks connected into a common vent header at the top of the stacks and extending to the open air above the roof at one point shall be sized in accordance with the requirements of Section 906.1, but shall not be smaller than the smalle st stack vent . The number of fixture units shall be the sum of all fixture units on all stacks connected thereto, and the developed length shall be the longest vent length from the intersection at the base of the most distant stack to the vent terminal in the open air, as a direct extension of one stack. 904.6 Sub - stack connections. Where it is desired to terminate stacks at a point below the roof terminus of the main vent stack, the sub - stack may connect to the main vent stack provided the portion of the m ain vent stack above the connection is sized for the total fixture unit load connected thereto, and for the maximum developed length of the stack or sub - stack. SECTION PC 905 VENT CONNECTIONS AND GRADES 905.1 Connection. Individual , branch and circuit vents shall connect to a vent stack, stack vent, or extend to the open air above the roof . VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 3 905.2 Grade. Vent and branch vent pipes shall be so graded and connected as to drain back to the drainage pipe by gravity. 905.3 Vent connection to drainage system. Every dry vent connecting to a horizontal drain shall connect above the centerline of the horizontal drain pipe. 905.4 Reserved. 905.5 Height above fixtures. A connection between a vent pipe and a vent stack or stack vent shall be made at not less than 6 inches (152 mm) above the flood level rim of the highest fixture served by the vent. Horizontal vent pipes forming branch vents, relief vents or loop vents shall be located not less than 6 inches (152 mm) above the flood level rim of the highest fix ture served. 905.6 Vent for future fixtures. Where the drainage piping has been roughed - in for future fixtures, a rough - in con- nection for a vent shall be installed. The vent size shall be not less than one - half the diameter of the rough - in drain to be serv ed. The vent rough - in shall connect to the vent system, or shall be vented by other means as provided for in this chapter. The connection shall be identified to indicate that it is a vent. SECTION PC 906 VENT PIPE SIZING 906.1 Size of stack vents and vent stacks. The minimum required diameter of stack vents and vent stacks shall be determined from the developed length and the total of drainage fixture units connected thereto in accordance with Table 906.1, but in no case shall the diameter be less than one - half the diameter of the drain served or less than 1 1 / 4 inches (32 mm). TABLE 906.1 SIZE AND DEVELOPED LENGTH OF STACK VENTS AND VENT STACKS DIAMETER OF SOIL OR WASTE STACK (inches) TOTAL FIXTURE UNITS BEING VENTED (dfu) MAXIMUM DEVELOPED LENGTH OF VENT (f eet) a DIAMETER OF VENT (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 5 6 8 10 12 1 1 / 4 2 30 — — — — — — — — — — 1 1 / 2 8 50 150 1 1 / 2 10 30 100 2 12 — 75 200 — — — — — — — — 2 20 30 50 150 — 2 1 / 2 42 26 30 100 300 3 10 — 42 150 360 1,040 — — — — — — 3 21 32 110 270 810 3 53 27 94 230 680 3 102 — 25 86 210 620 — — — — — — 4 43 — 35 85 250 980 4 140 — 27 65 200 750 4 320 — — 23 55 170 640 — — — — — VENTS 9 - 4 2022 NEW YORK CITY PLUMBING CODE 4 540 21 50 150 580 — 5 190 28 82 320 990 5 490 — — — 21 63 250 760 — — — — 5 940 18 53 210 670 5 1,400 16 49 190 590 6 500 — — — — 33 130 400 1,000 — — — 6 1,100 — 26 100 310 780 6 2,000 — 22 84 260 660 6 2,900 — — — — 20 77 240 600 — — — 8 1,800 — 31 95 240 940 8 3,400 — 24 73 190 729 8 5,600 — — — — — 20 62 160 610 — — 8 7,600 18 56 140 560 — 10 4,000 — 31 78 310 960 10 7,200 — — — — — — 24 60 240 740 — 10 11,000 20 51 200 630 10 15,000 18 46 180 571 12 7,300 — — — — — — — 31 120 380 940 12 13,000 — 24 94 300 720 12 20,000 — 20 79 250 610 12 26,000 — — — — — — — 18 72 230 500 15 15,000 — 40 130 310 15 25,000 — 31 96 240 15 38,000 — — — — — — — — 26 81 200 15 50,000 24 74 180 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm. a. The developed length shall be measured from the vent connection to the open air. 906.2 Vents other than stack vents or vent stacks. The diameter of individual vents, branch vents, circuit vents and relief vents shall be at least one - half the required diameter of the drain served. The required size of the drain shall be determined in accordance with Table 710.1(2). Vent pipes shall not be less than 1 1 / 4 inches (32 mm) in diameter. Vents shall be sized in accordance with Table 906.1 utilizing the drainage fixture units and the corresponding CHAPTER 9 VENTS SECTION PC 901 GENERAL 901.1 Scope. The provisions of this chapter shall govern the materials, design, construction and installation of vent systems except for vent systems for methane and radon which shall be governed by this section . 901.1.1 Methane and radon venting. The design and mater ials used in the installation of the methane and radon vent systems shall be approved by the commissioner and shall comply with all applicable rules of the Fire De- partment. 901.2 Trap seal protection. The plumbing system shall be provided with a system of vent piping that will permit the admission or emission of air so that the seal of any fixture trap shall not be subjected to a pressure differential of more than 1 inch of water column (249 Pa). 901.2.1 Venting required. Traps and trapped fixtures shall be vented in accordance with one of the venting meth- ods specified in this chapter. 901.3 Chemical waste vent systems. The vent system for a chemical waste system shall be independent of the sanitary vent system and shall terminate separately through the roof to the outdoors . 901.4 Use limitations. The plumbing vent system shall not be utilized for purposes other than the venting of the plumbing system. 901.5 Tests. The vent system shall be tested in accordance with Section 312. 901.6 Engineered systems. Engin eered venting systems shall conform to the provisions of Section 919 . SECTION PC 902 MATERIALS 902.1 Vents. The materials and methods utilized for the construction and installation of venting systems shall comply with the applicable provisions of Section 7 02. 902.2 Sheet copper. Sheet copper for vent pipe flashings shall conform to ASTM B 152 and shall weigh not less than 8 ounces per square foot (2.5 kg/m 2 ). 902.3 Sheet lead. Sheet lead for vent pipe flashings shall weigh not less than 3 pounds per square foot (15 kg/m 2 ) for field - constructed flashings and not less than 2 1 / 2 pounds per square foot (12 kg/m 2 ) for prefabricated flashings. SECTION PC 903 VENT TERMINALS 903.1 Roof extension. Open vent pipes that extend through a roof shall be terminated not less than 24 inches (610 mm) above the roof. Where a roof is to be used for assembly or as a promenade, observation deck, sun bathing deck or similar purposes, open vent pipes shall terminate not less than 7 feet (2134 mm) above the roof. Ap proved vandal - resistant vent caps may be used. 903.2 Frost closure. Vent extensions through a roof or wall shall be not less than 4 inches (102 mm) in diameter. Any increase in the size of the vent shall be made not less than 1 foot (305 mm) inside the the rmal envelope of the building. 903.3 Flashings. The juncture of each vent pipe with the roof line shall be made water tight by an approved flashing. 903.4 Prohibited use. A vent terminal shall not be used for any purpose other than a vent terminal. 903.5 Location of vent terminal. Locations of vent terminals shall comply with Sections 903.5.1 and 903.5.2. VENTS 9 - 2 2022 NEW YORK CITY PLUMBING CODE 903.5.1 New vent terminals. An open vent terminal from a drainage system of the new or altered building shall not be located directly beneath any door, o perable window, or other air intake opening of the building or of an adjacent building, and any such vent terminal shall not be within 10 feet (3048 mm) horizontally of such an opening unless it is at least 3 feet (914 mm) above the top of such opening. Wh en the consent of the owner of an adjoining taller build - ing is obtained, the owner of the new or altered building shall be permitted to carry the new vent stack, with adequate support, to a level above the higher existing roof. 903.5.2 New openings. A doo r, operable window, or other air intake opening of the new or altered building shall not be located within 10 feet (3048 mm) horizontally from an open vent terminal from a drainage system of an existing adjacent building unless the existing terminal is at least 3 feet (914 mm) above such opening. Whenever necessary, the owner of the new building shall at his or her own expense, and with approval of the adjoining owner, offset the vent stack of the adjacent existing building to a distance of 10 feet (3048 mm ) or more from such openings, or shall extend such vent stack to a height of at least 3 feet (924 mm) above the topmost opening. 903.6 Reserved. 903.7 Reserved. SECTION PC 904 OUTDOOR VENT EXTENSIONS 904 .1 Required vent extension. The vent system serving each building drain shall have not less than one vent pipe that extends to the outdoors. 904. 1.1 Installation. The required vent shall be a dry vent that connects to the building drain or an extension of a drain that connects to the building drain. Such vent shall not be an island fixture vent as allowed by Section 916. 904.1.2 Size. The required vent shall be sized in accordance with Section 906.2 based on the required size of the building drain. 904.2 Vent stack required. A vent stack shall be required for every drainage stack that has three branch intervals or more . 904.3 Vent termination. Vent stacks or stack vents shall terminate outdoors above the roof or to the stack vent portion of the soil or waste stack, at least 6 inches (152 mm) above the flood level of the highest fixture connection discharging into the soil or waste stack. 904.4 Vent connection at base. Vent stacks shall connect to the base of the drainage stack. The vent stack shall co nnect at or below the lowest horizontal branch. Where the vent stack connects to the building drain, the connection shall be located downstream of the drainage stack and within a distance of 10 times the diameter of the drainage stack. 904.5 Vent headers. Stack vents and vent stacks connected into a common vent header at the top of the stacks and extending to the open air above the roof at one point shall be sized in accordance with the requirements of Section 906.1, but shall not be smaller than the smalle st stack vent . The number of fixture units shall be the sum of all fixture units on all stacks connected thereto, and the developed length shall be the longest vent length from the intersection at the base of the most distant stack to the vent terminal in the open air, as a direct extension of one stack. 904.6 Sub - stack connections. Where it is desired to terminate stacks at a point below the roof terminus of the main vent stack, the sub - stack may connect to the main vent stack provided the portion of the m ain vent stack above the connection is sized for the total fixture unit load connected thereto, and for the maximum developed length of the stack or sub - stack. SECTION PC 905 VENT CONNECTIONS AND GRADES 905.1 Connection. Individual , branch and circuit vents shall connect to a vent stack, stack vent, or extend to the open air above the roof . VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 3 905.2 Grade. Vent and branch vent pipes shall be so graded and connected as to drain back to the drainage pipe by gravity. 905.3 Vent connection to drainage system. Every dry vent connecting to a horizontal drain shall connect above the centerline of the horizontal drain pipe. 905.4 Reserved. 905.5 Height above fixtures. A connection between a vent pipe and a vent stack or stack vent shall be made at not less than 6 inches (152 mm) above the flood level rim of the highest fixture served by the vent. Horizontal vent pipes forming branch vents, relief vents or loop vents shall be located not less than 6 inches (152 mm) above the flood level rim of the highest fix ture served. 905.6 Vent for future fixtures. Where the drainage piping has been roughed - in for future fixtures, a rough - in con- nection for a vent shall be installed. The vent size shall be not less than one - half the diameter of the rough - in drain to be serv ed. The vent rough - in shall connect to the vent system, or shall be vented by other means as provided for in this chapter. The connection shall be identified to indicate that it is a vent. SECTION PC 906 VENT PIPE SIZING 906.1 Size of stack vents and vent stacks. The minimum required diameter of stack vents and vent stacks shall be determined from the developed length and the total of drainage fixture units connected thereto in accordance with Table 906.1, but in no case shall the diameter be less than one - half the diameter of the drain served or less than 1 1 / 4 inches (32 mm). TABLE 906.1 SIZE AND DEVELOPED LENGTH OF STACK VENTS AND VENT STACKS DIAMETER OF SOIL OR WASTE STACK (inches) TOTAL FIXTURE UNITS BEING VENTED (dfu) MAXIMUM DEVELOPED LENGTH OF VENT (f eet) a DIAMETER OF VENT (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 5 6 8 10 12 1 1 / 4 2 30 — — — — — — — — — — 1 1 / 2 8 50 150 1 1 / 2 10 30 100 2 12 — 75 200 — — — — — — — — 2 20 30 50 150 — 2 1 / 2 42 26 30 100 300 3 10 — 42 150 360 1,040 — — — — — — 3 21 32 110 270 810 3 53 27 94 230 680 3 102 — 25 86 210 620 — — — — — — 4 43 — 35 85 250 980 4 140 — 27 65 200 750 4 320 — — 23 55 170 640 — — — — — VENTS 9 - 4 2022 NEW YORK CITY PLUMBING CODE 4 540 21 50 150 580 — 5 190 28 82 320 990 5 490 — — — 21 63 250 760 — — — — 5 940 18 53 210 670 5 1,400 16 49 190 590 6 500 — — — — 33 130 400 1,000 — — — 6 1,100 — 26 100 310 780 6 2,000 — 22 84 260 660 6 2,900 — — — — 20 77 240 600 — — — 8 1,800 — 31 95 240 940 8 3,400 — 24 73 190 729 8 5,600 — — — — — 20 62 160 610 — — 8 7,600 18 56 140 560 — 10 4,000 — 31 78 310 960 10 7,200 — — — — — — 24 60 240 740 — 10 11,000 20 51 200 630 10 15,000 18 46 180 571 12 7,300 — — — — — — — 31 120 380 940 12 13,000 — 24 94 300 720 12 20,000 — 20 79 250 610 12 26,000 — — — — — — — 18 72 230 500 15 15,000 — 40 130 310 15 25,000 — 31 96 240 15 38,000 — — — — — — — — 26 81 200 15 50,000 24 74 180 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm. a. The developed length shall be measured from the vent connection to the open air. 906.2 Vents other than stack vents or vent stacks. The diameter of individual vents, branch vents, circuit vents and relief vents shall be at least one - half the required diameter of the drain served. The required size of the drain shall be determined in accordance with Table 710.1(2). Vent pipes shall not be less than 1 1 / 4 inches (32 mm) in diameter. Vents shall be sized in accordance with Table 906.1 utilizing the drainage fixture units and the corresponding VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 5 developed length. Relief vents for soil and waste stacks in buildings having more than 10 branch intervals shall be sized in accordance with Section 908.2. 906.3 Developed length. The developed length of individual, branch, circuit and relief vents shall be measured from the farthest point of vent connection to the drainage system to the point of connection to the vent stack, stack vent or termination outside of the building. 906.4 Multiple branch vents. Where multiple branch vents are connected to a common branch vent, the common branch vent shall be sized in accordance with this section based on the size of the co mmon horizontal drainage branch that is or would be required to serve the total drainage fixture unit load being vented. 906.5 Ejector vents. Ejector vent sizes shall be determined in accordance with Sections 906.5.1 and 906.5.2. 906.5.1 Sewage pumps and s ewage ejectors other than pneumatic. Drainage piping below sewer level shall be vented in the same manner as that of a gravity system. Building sump vent sizes for sumps with sewage pumps or sewage ejectors, other than pneumatic, shall be determined in acc ordance with Table 906.5.1. Where a building sump vent connects to a sanitary vent system, the sanitary branch vent shall be at least 3 inches (76 mm) in diameter. TABLE 906.5.1 SIZE AND LENGTH OF SUMP VENTS DISCHARGE CAPACITY OF PUMP (gpm) MAXIMUM DEVELOP ED LENGTH OF VENT (feet) a Diameter of vent (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 10 No limit b No limit No limit No limit No limit No limit 20 270 No limit No limit No limit No limit No limit 40 72 160 No limit No limit No limit No limit 60 31 75 270 No limit No limit No limit 80 16 41 150 380 No limit No limit 100 10 c 25 97 250 No limit No limit 150 Not permitted 10 c 44 110 370 No limit 200 Not permitted Not permitted 20 60 210 No limit 250 Not permitted Not permitted 10 36 132 No limit 300 Not permitted Not permitted 10 c 22 88 380 400 Not permitted Not permitted Not permitted 10 c 44 210 500 Not permitted Not permitted Not permitted Not permitted 24 130 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 gallon per minute = 3.785 L/m. a. Developed length plus an appropriate allowance for entrance losses and friction due to fittings, changes in direction and dia meter. Suggested allowances shall be obtained from NBS Monograph 31 or other approved sources. An allowance of 50 percent of the de veloped length shall be assumed if a more precise value is not available. b. Actual values greater than 500 feet. c. Less than 10 feet. 906.5.2 Pneumatic sewage ejectors. The air pressure relief pipe from a pneumatic sewage ejector shall be con- nected to a n independent vent stack terminating as required for vent extensions through the roof. The relief pipe VENTS 9 - 6 2022 NEW YORK CITY PLUMBING CODE shall be sized to relieve air pressure inside the ejector to atmospheric pressure, but shall be not less than 1 1 / 2 inches (38 mm) in size. SECTION PC 907 VENTS FOR STACK OFFSETS 907.1 Vent for horizontal offset of drainage stack. Horizontal offsets of drainage stacks shall be vented where five or more branch intervals are located above the offset. The offset shall be vented by venting the upper section of the drainage stack and the lower section of the drainage stack. 907.2 Upper section. The upper section of the drainage stack shall be vented as a separate stack with a vent stack connection installed in accordance with Section 904.4. The offset shall be considered the base of the stack. 907.3 Lower section. The lower section of the drainage stack shall be vented by a yoke vent connecting between the offset and the next lower horizontal branch. The yoke vent connection shall be permitted to be a vertical extension of the drainage stack. The size of the yoke vent and connection shall be a minimum of the size required for the vent stack of the drainage stack. SECTION PC 908 RELIEF VENTS — STACKS OF MORE THAN 10 BRANCH INTERVALS 908.1 Where required. Soil and w aste stacks in buildings having more than 10 branch intervals shall be provided with a relief vent at each tenth interval installed, beginning with the top floor. 908.2 Size and connection. The size of the relief vent shall be equal to the size of the vent stack to which it connects. The lower end of each relief vent shall connect to the soil or waste stack through a wye below the horizontal branch serving the floor, and the upper end shall connect to the vent stack through a tee or inverted wye not less th an 3 feet (914 mm) above the floor. SECTION PC 909 FIXTURE VENTS 909.1 Distance of trap from vent. Each fixture trap shall have a protecting vent located so that the slope and the developed length in the fixture drain from the trap weir to the vent fitting are within the requirements set forth in Table 909.1. Exception: The developed length of the fixture drain from the trap weir to the vent fitting for self - siphoning fix- tures, such as water closets, shall not be limited. TABLE 909.1 MAXIMUM DISTANCE OF FIX TURE TRAP FROM VENT SIZE OF TRAP (inches) SLOPE (inch per foot) DISTANCE FROM TRAP (feet) 1 1 / 4 1 / 4 5 1 1 / 2 1 / 4 6 2 1 / 4 8 3 1 / 8 12 4 1 / 8 16 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 inch per foot = 83.3 mm/m. VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 7 909.2 Venting of fixture drains. The vent for a fixture drain, except where serving a fixture with integral traps, such as water closets, shall connect above the weir of the fixture trap being vented. 909.3 Crown vent. A vent shall not be installed within two pipe diameters of the trap weir . SECTION PC 910 INDIVIDUAL VENT 910.1 Individual vent permitted. Each trap and trapped fixture is permitted to be provided with an individual vent. The individual vent shall connect to the fixture drain of the trap or trapped fixture being vente d in accordance with section 909.1, but at a distance not to exceed 16 feet (4876 mm). 910.2 Floor drain vents. No vents will be required for piping serving floor drains when the floor drain is located not more than 15 feet (4572 mm) from the vented line to which it connects. SECTION PC 911 COMMON VENT 911.1 Individual vent as common vent. An individual vent is permitted to vent two traps or trapped fixtures as a common vent. The traps or trapped fixtures being common vented shall be located on the same floor level. 911.2 Connection at the same level. Where the fixture drains being common vented connect at the same level, the vent connection shall be at the interconnection of the fixture drains. Exception: Where wet vents are permitted by this code, the wet vent connection may be located downstream of the interconnection. 911.3 Connection at different levels. Where the fixture drains connect at different levels, the vent shall connect as a vertical extension of the vertical drain. The vertical drain p ipe connecting the two fixture drains shall be considered the vent for the lower fixture drain, and shall be sized in accordance with Table 911.3 . The upper fixture shall not be a water closet. TABLE 911.3 COMMON VENT SIZES PIPE SIZE (inches) MAXIMUM DISCH ARGE FROM UPPER FIXTURE DRAIN (dfu) 1 1 / 2 1 2 4 2 1 / 2 to 3 6 For SI: 1 inch = 25.4 mm. SECTION PC 912 WET VENTING 912.1 Horizontal wet vent permitted. Any combination of fixtures within one bathroom group located in the same room is permitted to be vented by a horizontal wet vent. The wet vent shall be considered the vent for the fixtures and shall extend from the connection of the dry vent along the direction of the flow in the drain pipe to the most down- stream fixture drain connection to the horizo ntal branch drain. Each wet - vented fixture drain shall connect inde- pendently to the horizontal wet vent. Only the fixtures within the bathroom groups shall connect to the wet - vented horizontal branch drain. Any additional fixtures shall discharge downstrea m of the horizontal wet vent. 912.1.1 Vertical wet vent permitted. Any combination of fixtures within one bathroom group is permitted to be vented by a vertical wet vent. The vertical wet vent shall be considered the vent for the fixtures and shall extend CHAPTER 9 VENTS SECTION PC 901 GENERAL 901.1 Scope. The provisions of this chapter shall govern the materials, design, construction and installation of vent systems except for vent systems for methane and radon which shall be governed by this section . 901.1.1 Methane and radon venting. The design and mater ials used in the installation of the methane and radon vent systems shall be approved by the commissioner and shall comply with all applicable rules of the Fire De- partment. 901.2 Trap seal protection. The plumbing system shall be provided with a system of vent piping that will permit the admission or emission of air so that the seal of any fixture trap shall not be subjected to a pressure differential of more than 1 inch of water column (249 Pa). 901.2.1 Venting required. Traps and trapped fixtures shall be vented in accordance with one of the venting meth- ods specified in this chapter. 901.3 Chemical waste vent systems. The vent system for a chemical waste system shall be independent of the sanitary vent system and shall terminate separately through the roof to the outdoors . 901.4 Use limitations. The plumbing vent system shall not be utilized for purposes other than the venting of the plumbing system. 901.5 Tests. The vent system shall be tested in accordance with Section 312. 901.6 Engineered systems. Engin eered venting systems shall conform to the provisions of Section 919 . SECTION PC 902 MATERIALS 902.1 Vents. The materials and methods utilized for the construction and installation of venting systems shall comply with the applicable provisions of Section 7 02. 902.2 Sheet copper. Sheet copper for vent pipe flashings shall conform to ASTM B 152 and shall weigh not less than 8 ounces per square foot (2.5 kg/m 2 ). 902.3 Sheet lead. Sheet lead for vent pipe flashings shall weigh not less than 3 pounds per square foot (15 kg/m 2 ) for field - constructed flashings and not less than 2 1 / 2 pounds per square foot (12 kg/m 2 ) for prefabricated flashings. SECTION PC 903 VENT TERMINALS 903.1 Roof extension. Open vent pipes that extend through a roof shall be terminated not less than 24 inches (610 mm) above the roof. Where a roof is to be used for assembly or as a promenade, observation deck, sun bathing deck or similar purposes, open vent pipes shall terminate not less than 7 feet (2134 mm) above the roof. Ap proved vandal - resistant vent caps may be used. 903.2 Frost closure. Vent extensions through a roof or wall shall be not less than 4 inches (102 mm) in diameter. Any increase in the size of the vent shall be made not less than 1 foot (305 mm) inside the the rmal envelope of the building. 903.3 Flashings. The juncture of each vent pipe with the roof line shall be made water tight by an approved flashing. 903.4 Prohibited use. A vent terminal shall not be used for any purpose other than a vent terminal. 903.5 Location of vent terminal. Locations of vent terminals shall comply with Sections 903.5.1 and 903.5.2. VENTS 9 - 2 2022 NEW YORK CITY PLUMBING CODE 903.5.1 New vent terminals. An open vent terminal from a drainage system of the new or altered building shall not be located directly beneath any door, o perable window, or other air intake opening of the building or of an adjacent building, and any such vent terminal shall not be within 10 feet (3048 mm) horizontally of such an opening unless it is at least 3 feet (914 mm) above the top of such opening. Wh en the consent of the owner of an adjoining taller build - ing is obtained, the owner of the new or altered building shall be permitted to carry the new vent stack, with adequate support, to a level above the higher existing roof. 903.5.2 New openings. A doo r, operable window, or other air intake opening of the new or altered building shall not be located within 10 feet (3048 mm) horizontally from an open vent terminal from a drainage system of an existing adjacent building unless the existing terminal is at least 3 feet (914 mm) above such opening. Whenever necessary, the owner of the new building shall at his or her own expense, and with approval of the adjoining owner, offset the vent stack of the adjacent existing building to a distance of 10 feet (3048 mm ) or more from such openings, or shall extend such vent stack to a height of at least 3 feet (924 mm) above the topmost opening. 903.6 Reserved. 903.7 Reserved. SECTION PC 904 OUTDOOR VENT EXTENSIONS 904 .1 Required vent extension. The vent system serving each building drain shall have not less than one vent pipe that extends to the outdoors. 904. 1.1 Installation. The required vent shall be a dry vent that connects to the building drain or an extension of a drain that connects to the building drain. Such vent shall not be an island fixture vent as allowed by Section 916. 904.1.2 Size. The required vent shall be sized in accordance with Section 906.2 based on the required size of the building drain. 904.2 Vent stack required. A vent stack shall be required for every drainage stack that has three branch intervals or more . 904.3 Vent termination. Vent stacks or stack vents shall terminate outdoors above the roof or to the stack vent portion of the soil or waste stack, at least 6 inches (152 mm) above the flood level of the highest fixture connection discharging into the soil or waste stack. 904.4 Vent connection at base. Vent stacks shall connect to the base of the drainage stack. The vent stack shall co nnect at or below the lowest horizontal branch. Where the vent stack connects to the building drain, the connection shall be located downstream of the drainage stack and within a distance of 10 times the diameter of the drainage stack. 904.5 Vent headers. Stack vents and vent stacks connected into a common vent header at the top of the stacks and extending to the open air above the roof at one point shall be sized in accordance with the requirements of Section 906.1, but shall not be smaller than the smalle st stack vent . The number of fixture units shall be the sum of all fixture units on all stacks connected thereto, and the developed length shall be the longest vent length from the intersection at the base of the most distant stack to the vent terminal in the open air, as a direct extension of one stack. 904.6 Sub - stack connections. Where it is desired to terminate stacks at a point below the roof terminus of the main vent stack, the sub - stack may connect to the main vent stack provided the portion of the m ain vent stack above the connection is sized for the total fixture unit load connected thereto, and for the maximum developed length of the stack or sub - stack. SECTION PC 905 VENT CONNECTIONS AND GRADES 905.1 Connection. Individual , branch and circuit vents shall connect to a vent stack, stack vent, or extend to the open air above the roof . VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 3 905.2 Grade. Vent and branch vent pipes shall be so graded and connected as to drain back to the drainage pipe by gravity. 905.3 Vent connection to drainage system. Every dry vent connecting to a horizontal drain shall connect above the centerline of the horizontal drain pipe. 905.4 Reserved. 905.5 Height above fixtures. A connection between a vent pipe and a vent stack or stack vent shall be made at not less than 6 inches (152 mm) above the flood level rim of the highest fixture served by the vent. Horizontal vent pipes forming branch vents, relief vents or loop vents shall be located not less than 6 inches (152 mm) above the flood level rim of the highest fix ture served. 905.6 Vent for future fixtures. Where the drainage piping has been roughed - in for future fixtures, a rough - in con- nection for a vent shall be installed. The vent size shall be not less than one - half the diameter of the rough - in drain to be serv ed. The vent rough - in shall connect to the vent system, or shall be vented by other means as provided for in this chapter. The connection shall be identified to indicate that it is a vent. SECTION PC 906 VENT PIPE SIZING 906.1 Size of stack vents and vent stacks. The minimum required diameter of stack vents and vent stacks shall be determined from the developed length and the total of drainage fixture units connected thereto in accordance with Table 906.1, but in no case shall the diameter be less than one - half the diameter of the drain served or less than 1 1 / 4 inches (32 mm). TABLE 906.1 SIZE AND DEVELOPED LENGTH OF STACK VENTS AND VENT STACKS DIAMETER OF SOIL OR WASTE STACK (inches) TOTAL FIXTURE UNITS BEING VENTED (dfu) MAXIMUM DEVELOPED LENGTH OF VENT (f eet) a DIAMETER OF VENT (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 5 6 8 10 12 1 1 / 4 2 30 — — — — — — — — — — 1 1 / 2 8 50 150 1 1 / 2 10 30 100 2 12 — 75 200 — — — — — — — — 2 20 30 50 150 — 2 1 / 2 42 26 30 100 300 3 10 — 42 150 360 1,040 — — — — — — 3 21 32 110 270 810 3 53 27 94 230 680 3 102 — 25 86 210 620 — — — — — — 4 43 — 35 85 250 980 4 140 — 27 65 200 750 4 320 — — 23 55 170 640 — — — — — VENTS 9 - 4 2022 NEW YORK CITY PLUMBING CODE 4 540 21 50 150 580 — 5 190 28 82 320 990 5 490 — — — 21 63 250 760 — — — — 5 940 18 53 210 670 5 1,400 16 49 190 590 6 500 — — — — 33 130 400 1,000 — — — 6 1,100 — 26 100 310 780 6 2,000 — 22 84 260 660 6 2,900 — — — — 20 77 240 600 — — — 8 1,800 — 31 95 240 940 8 3,400 — 24 73 190 729 8 5,600 — — — — — 20 62 160 610 — — 8 7,600 18 56 140 560 — 10 4,000 — 31 78 310 960 10 7,200 — — — — — — 24 60 240 740 — 10 11,000 20 51 200 630 10 15,000 18 46 180 571 12 7,300 — — — — — — — 31 120 380 940 12 13,000 — 24 94 300 720 12 20,000 — 20 79 250 610 12 26,000 — — — — — — — 18 72 230 500 15 15,000 — 40 130 310 15 25,000 — 31 96 240 15 38,000 — — — — — — — — 26 81 200 15 50,000 24 74 180 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm. a. The developed length shall be measured from the vent connection to the open air. 906.2 Vents other than stack vents or vent stacks. The diameter of individual vents, branch vents, circuit vents and relief vents shall be at least one - half the required diameter of the drain served. The required size of the drain shall be determined in accordance with Table 710.1(2). Vent pipes shall not be less than 1 1 / 4 inches (32 mm) in diameter. Vents shall be sized in accordance with Table 906.1 utilizing the drainage fixture units and the corresponding VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 5 developed length. Relief vents for soil and waste stacks in buildings having more than 10 branch intervals shall be sized in accordance with Section 908.2. 906.3 Developed length. The developed length of individual, branch, circuit and relief vents shall be measured from the farthest point of vent connection to the drainage system to the point of connection to the vent stack, stack vent or termination outside of the building. 906.4 Multiple branch vents. Where multiple branch vents are connected to a common branch vent, the common branch vent shall be sized in accordance with this section based on the size of the co mmon horizontal drainage branch that is or would be required to serve the total drainage fixture unit load being vented. 906.5 Ejector vents. Ejector vent sizes shall be determined in accordance with Sections 906.5.1 and 906.5.2. 906.5.1 Sewage pumps and s ewage ejectors other than pneumatic. Drainage piping below sewer level shall be vented in the same manner as that of a gravity system. Building sump vent sizes for sumps with sewage pumps or sewage ejectors, other than pneumatic, shall be determined in acc ordance with Table 906.5.1. Where a building sump vent connects to a sanitary vent system, the sanitary branch vent shall be at least 3 inches (76 mm) in diameter. TABLE 906.5.1 SIZE AND LENGTH OF SUMP VENTS DISCHARGE CAPACITY OF PUMP (gpm) MAXIMUM DEVELOP ED LENGTH OF VENT (feet) a Diameter of vent (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 10 No limit b No limit No limit No limit No limit No limit 20 270 No limit No limit No limit No limit No limit 40 72 160 No limit No limit No limit No limit 60 31 75 270 No limit No limit No limit 80 16 41 150 380 No limit No limit 100 10 c 25 97 250 No limit No limit 150 Not permitted 10 c 44 110 370 No limit 200 Not permitted Not permitted 20 60 210 No limit 250 Not permitted Not permitted 10 36 132 No limit 300 Not permitted Not permitted 10 c 22 88 380 400 Not permitted Not permitted Not permitted 10 c 44 210 500 Not permitted Not permitted Not permitted Not permitted 24 130 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 gallon per minute = 3.785 L/m. a. Developed length plus an appropriate allowance for entrance losses and friction due to fittings, changes in direction and dia meter. Suggested allowances shall be obtained from NBS Monograph 31 or other approved sources. An allowance of 50 percent of the de veloped length shall be assumed if a more precise value is not available. b. Actual values greater than 500 feet. c. Less than 10 feet. 906.5.2 Pneumatic sewage ejectors. The air pressure relief pipe from a pneumatic sewage ejector shall be con- nected to a n independent vent stack terminating as required for vent extensions through the roof. The relief pipe VENTS 9 - 6 2022 NEW YORK CITY PLUMBING CODE shall be sized to relieve air pressure inside the ejector to atmospheric pressure, but shall be not less than 1 1 / 2 inches (38 mm) in size. SECTION PC 907 VENTS FOR STACK OFFSETS 907.1 Vent for horizontal offset of drainage stack. Horizontal offsets of drainage stacks shall be vented where five or more branch intervals are located above the offset. The offset shall be vented by venting the upper section of the drainage stack and the lower section of the drainage stack. 907.2 Upper section. The upper section of the drainage stack shall be vented as a separate stack with a vent stack connection installed in accordance with Section 904.4. The offset shall be considered the base of the stack. 907.3 Lower section. The lower section of the drainage stack shall be vented by a yoke vent connecting between the offset and the next lower horizontal branch. The yoke vent connection shall be permitted to be a vertical extension of the drainage stack. The size of the yoke vent and connection shall be a minimum of the size required for the vent stack of the drainage stack. SECTION PC 908 RELIEF VENTS — STACKS OF MORE THAN 10 BRANCH INTERVALS 908.1 Where required. Soil and w aste stacks in buildings having more than 10 branch intervals shall be provided with a relief vent at each tenth interval installed, beginning with the top floor. 908.2 Size and connection. The size of the relief vent shall be equal to the size of the vent stack to which it connects. The lower end of each relief vent shall connect to the soil or waste stack through a wye below the horizontal branch serving the floor, and the upper end shall connect to the vent stack through a tee or inverted wye not less th an 3 feet (914 mm) above the floor. SECTION PC 909 FIXTURE VENTS 909.1 Distance of trap from vent. Each fixture trap shall have a protecting vent located so that the slope and the developed length in the fixture drain from the trap weir to the vent fitting are within the requirements set forth in Table 909.1. Exception: The developed length of the fixture drain from the trap weir to the vent fitting for self - siphoning fix- tures, such as water closets, shall not be limited. TABLE 909.1 MAXIMUM DISTANCE OF FIX TURE TRAP FROM VENT SIZE OF TRAP (inches) SLOPE (inch per foot) DISTANCE FROM TRAP (feet) 1 1 / 4 1 / 4 5 1 1 / 2 1 / 4 6 2 1 / 4 8 3 1 / 8 12 4 1 / 8 16 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 inch per foot = 83.3 mm/m. VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 7 909.2 Venting of fixture drains. The vent for a fixture drain, except where serving a fixture with integral traps, such as water closets, shall connect above the weir of the fixture trap being vented. 909.3 Crown vent. A vent shall not be installed within two pipe diameters of the trap weir . SECTION PC 910 INDIVIDUAL VENT 910.1 Individual vent permitted. Each trap and trapped fixture is permitted to be provided with an individual vent. The individual vent shall connect to the fixture drain of the trap or trapped fixture being vente d in accordance with section 909.1, but at a distance not to exceed 16 feet (4876 mm). 910.2 Floor drain vents. No vents will be required for piping serving floor drains when the floor drain is located not more than 15 feet (4572 mm) from the vented line to which it connects. SECTION PC 911 COMMON VENT 911.1 Individual vent as common vent. An individual vent is permitted to vent two traps or trapped fixtures as a common vent. The traps or trapped fixtures being common vented shall be located on the same floor level. 911.2 Connection at the same level. Where the fixture drains being common vented connect at the same level, the vent connection shall be at the interconnection of the fixture drains. Exception: Where wet vents are permitted by this code, the wet vent connection may be located downstream of the interconnection. 911.3 Connection at different levels. Where the fixture drains connect at different levels, the vent shall connect as a vertical extension of the vertical drain. The vertical drain p ipe connecting the two fixture drains shall be considered the vent for the lower fixture drain, and shall be sized in accordance with Table 911.3 . The upper fixture shall not be a water closet. TABLE 911.3 COMMON VENT SIZES PIPE SIZE (inches) MAXIMUM DISCH ARGE FROM UPPER FIXTURE DRAIN (dfu) 1 1 / 2 1 2 4 2 1 / 2 to 3 6 For SI: 1 inch = 25.4 mm. SECTION PC 912 WET VENTING 912.1 Horizontal wet vent permitted. Any combination of fixtures within one bathroom group located in the same room is permitted to be vented by a horizontal wet vent. The wet vent shall be considered the vent for the fixtures and shall extend from the connection of the dry vent along the direction of the flow in the drain pipe to the most down- stream fixture drain connection to the horizo ntal branch drain. Each wet - vented fixture drain shall connect inde- pendently to the horizontal wet vent. Only the fixtures within the bathroom groups shall connect to the wet - vented horizontal branch drain. Any additional fixtures shall discharge downstrea m of the horizontal wet vent. 912.1.1 Vertical wet vent permitted. Any combination of fixtures within one bathroom group is permitted to be vented by a vertical wet vent. The vertical wet vent shall be considered the vent for the fixtures and shall extend CHAPTER 9 VENTS SECTION PC 901 GENERAL 901.1 Scope. The provisions of this chapter shall govern the materials, design, construction and installation of vent systems except for vent systems for methane and radon which shall be governed by this section . 901.1.1 Methane and radon venting. The design and mater ials used in the installation of the methane and radon vent systems shall be approved by the commissioner and shall comply with all applicable rules of the Fire De- partment. 901.2 Trap seal protection. The plumbing system shall be provided with a system of vent piping that will permit the admission or emission of air so that the seal of any fixture trap shall not be subjected to a pressure differential of more than 1 inch of water column (249 Pa). 901.2.1 Venting required. Traps and trapped fixtures shall be vented in accordance with one of the venting meth- ods specified in this chapter. 901.3 Chemical waste vent systems. The vent system for a chemical waste system shall be independent of the sanitary vent system and shall terminate separately through the roof to the outdoors . 901.4 Use limitations. The plumbing vent system shall not be utilized for purposes other than the venting of the plumbing system. 901.5 Tests. The vent system shall be tested in accordance with Section 312. 901.6 Engineered systems. Engin eered venting systems shall conform to the provisions of Section 919 . SECTION PC 902 MATERIALS 902.1 Vents. The materials and methods utilized for the construction and installation of venting systems shall comply with the applicable provisions of Section 7 02. 902.2 Sheet copper. Sheet copper for vent pipe flashings shall conform to ASTM B 152 and shall weigh not less than 8 ounces per square foot (2.5 kg/m 2 ). 902.3 Sheet lead. Sheet lead for vent pipe flashings shall weigh not less than 3 pounds per square foot (15 kg/m 2 ) for field - constructed flashings and not less than 2 1 / 2 pounds per square foot (12 kg/m 2 ) for prefabricated flashings. SECTION PC 903 VENT TERMINALS 903.1 Roof extension. Open vent pipes that extend through a roof shall be terminated not less than 24 inches (610 mm) above the roof. Where a roof is to be used for assembly or as a promenade, observation deck, sun bathing deck or similar purposes, open vent pipes shall terminate not less than 7 feet (2134 mm) above the roof. Ap proved vandal - resistant vent caps may be used. 903.2 Frost closure. Vent extensions through a roof or wall shall be not less than 4 inches (102 mm) in diameter. Any increase in the size of the vent shall be made not less than 1 foot (305 mm) inside the the rmal envelope of the building. 903.3 Flashings. The juncture of each vent pipe with the roof line shall be made water tight by an approved flashing. 903.4 Prohibited use. A vent terminal shall not be used for any purpose other than a vent terminal. 903.5 Location of vent terminal. Locations of vent terminals shall comply with Sections 903.5.1 and 903.5.2. VENTS 9 - 2 2022 NEW YORK CITY PLUMBING CODE 903.5.1 New vent terminals. An open vent terminal from a drainage system of the new or altered building shall not be located directly beneath any door, o perable window, or other air intake opening of the building or of an adjacent building, and any such vent terminal shall not be within 10 feet (3048 mm) horizontally of such an opening unless it is at least 3 feet (914 mm) above the top of such opening. Wh en the consent of the owner of an adjoining taller build - ing is obtained, the owner of the new or altered building shall be permitted to carry the new vent stack, with adequate support, to a level above the higher existing roof. 903.5.2 New openings. A doo r, operable window, or other air intake opening of the new or altered building shall not be located within 10 feet (3048 mm) horizontally from an open vent terminal from a drainage system of an existing adjacent building unless the existing terminal is at least 3 feet (914 mm) above such opening. Whenever necessary, the owner of the new building shall at his or her own expense, and with approval of the adjoining owner, offset the vent stack of the adjacent existing building to a distance of 10 feet (3048 mm ) or more from such openings, or shall extend such vent stack to a height of at least 3 feet (924 mm) above the topmost opening. 903.6 Reserved. 903.7 Reserved. SECTION PC 904 OUTDOOR VENT EXTENSIONS 904 .1 Required vent extension. The vent system serving each building drain shall have not less than one vent pipe that extends to the outdoors. 904. 1.1 Installation. The required vent shall be a dry vent that connects to the building drain or an extension of a drain that connects to the building drain. Such vent shall not be an island fixture vent as allowed by Section 916. 904.1.2 Size. The required vent shall be sized in accordance with Section 906.2 based on the required size of the building drain. 904.2 Vent stack required. A vent stack shall be required for every drainage stack that has three branch intervals or more . 904.3 Vent termination. Vent stacks or stack vents shall terminate outdoors above the roof or to the stack vent portion of the soil or waste stack, at least 6 inches (152 mm) above the flood level of the highest fixture connection discharging into the soil or waste stack. 904.4 Vent connection at base. Vent stacks shall connect to the base of the drainage stack. The vent stack shall co nnect at or below the lowest horizontal branch. Where the vent stack connects to the building drain, the connection shall be located downstream of the drainage stack and within a distance of 10 times the diameter of the drainage stack. 904.5 Vent headers. Stack vents and vent stacks connected into a common vent header at the top of the stacks and extending to the open air above the roof at one point shall be sized in accordance with the requirements of Section 906.1, but shall not be smaller than the smalle st stack vent . The number of fixture units shall be the sum of all fixture units on all stacks connected thereto, and the developed length shall be the longest vent length from the intersection at the base of the most distant stack to the vent terminal in the open air, as a direct extension of one stack. 904.6 Sub - stack connections. Where it is desired to terminate stacks at a point below the roof terminus of the main vent stack, the sub - stack may connect to the main vent stack provided the portion of the m ain vent stack above the connection is sized for the total fixture unit load connected thereto, and for the maximum developed length of the stack or sub - stack. SECTION PC 905 VENT CONNECTIONS AND GRADES 905.1 Connection. Individual , branch and circuit vents shall connect to a vent stack, stack vent, or extend to the open air above the roof . VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 3 905.2 Grade. Vent and branch vent pipes shall be so graded and connected as to drain back to the drainage pipe by gravity. 905.3 Vent connection to drainage system. Every dry vent connecting to a horizontal drain shall connect above the centerline of the horizontal drain pipe. 905.4 Reserved. 905.5 Height above fixtures. A connection between a vent pipe and a vent stack or stack vent shall be made at not less than 6 inches (152 mm) above the flood level rim of the highest fixture served by the vent. Horizontal vent pipes forming branch vents, relief vents or loop vents shall be located not less than 6 inches (152 mm) above the flood level rim of the highest fix ture served. 905.6 Vent for future fixtures. Where the drainage piping has been roughed - in for future fixtures, a rough - in con- nection for a vent shall be installed. The vent size shall be not less than one - half the diameter of the rough - in drain to be serv ed. The vent rough - in shall connect to the vent system, or shall be vented by other means as provided for in this chapter. The connection shall be identified to indicate that it is a vent. SECTION PC 906 VENT PIPE SIZING 906.1 Size of stack vents and vent stacks. The minimum required diameter of stack vents and vent stacks shall be determined from the developed length and the total of drainage fixture units connected thereto in accordance with Table 906.1, but in no case shall the diameter be less than one - half the diameter of the drain served or less than 1 1 / 4 inches (32 mm). TABLE 906.1 SIZE AND DEVELOPED LENGTH OF STACK VENTS AND VENT STACKS DIAMETER OF SOIL OR WASTE STACK (inches) TOTAL FIXTURE UNITS BEING VENTED (dfu) MAXIMUM DEVELOPED LENGTH OF VENT (f eet) a DIAMETER OF VENT (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 5 6 8 10 12 1 1 / 4 2 30 — — — — — — — — — — 1 1 / 2 8 50 150 1 1 / 2 10 30 100 2 12 — 75 200 — — — — — — — — 2 20 30 50 150 — 2 1 / 2 42 26 30 100 300 3 10 — 42 150 360 1,040 — — — — — — 3 21 32 110 270 810 3 53 27 94 230 680 3 102 — 25 86 210 620 — — — — — — 4 43 — 35 85 250 980 4 140 — 27 65 200 750 4 320 — — 23 55 170 640 — — — — — VENTS 9 - 4 2022 NEW YORK CITY PLUMBING CODE 4 540 21 50 150 580 — 5 190 28 82 320 990 5 490 — — — 21 63 250 760 — — — — 5 940 18 53 210 670 5 1,400 16 49 190 590 6 500 — — — — 33 130 400 1,000 — — — 6 1,100 — 26 100 310 780 6 2,000 — 22 84 260 660 6 2,900 — — — — 20 77 240 600 — — — 8 1,800 — 31 95 240 940 8 3,400 — 24 73 190 729 8 5,600 — — — — — 20 62 160 610 — — 8 7,600 18 56 140 560 — 10 4,000 — 31 78 310 960 10 7,200 — — — — — — 24 60 240 740 — 10 11,000 20 51 200 630 10 15,000 18 46 180 571 12 7,300 — — — — — — — 31 120 380 940 12 13,000 — 24 94 300 720 12 20,000 — 20 79 250 610 12 26,000 — — — — — — — 18 72 230 500 15 15,000 — 40 130 310 15 25,000 — 31 96 240 15 38,000 — — — — — — — — 26 81 200 15 50,000 24 74 180 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm. a. The developed length shall be measured from the vent connection to the open air. 906.2 Vents other than stack vents or vent stacks. The diameter of individual vents, branch vents, circuit vents and relief vents shall be at least one - half the required diameter of the drain served. The required size of the drain shall be determined in accordance with Table 710.1(2). Vent pipes shall not be less than 1 1 / 4 inches (32 mm) in diameter. Vents shall be sized in accordance with Table 906.1 utilizing the drainage fixture units and the corresponding VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 5 developed length. Relief vents for soil and waste stacks in buildings having more than 10 branch intervals shall be sized in accordance with Section 908.2. 906.3 Developed length. The developed length of individual, branch, circuit and relief vents shall be measured from the farthest point of vent connection to the drainage system to the point of connection to the vent stack, stack vent or termination outside of the building. 906.4 Multiple branch vents. Where multiple branch vents are connected to a common branch vent, the common branch vent shall be sized in accordance with this section based on the size of the co mmon horizontal drainage branch that is or would be required to serve the total drainage fixture unit load being vented. 906.5 Ejector vents. Ejector vent sizes shall be determined in accordance with Sections 906.5.1 and 906.5.2. 906.5.1 Sewage pumps and s ewage ejectors other than pneumatic. Drainage piping below sewer level shall be vented in the same manner as that of a gravity system. Building sump vent sizes for sumps with sewage pumps or sewage ejectors, other than pneumatic, shall be determined in acc ordance with Table 906.5.1. Where a building sump vent connects to a sanitary vent system, the sanitary branch vent shall be at least 3 inches (76 mm) in diameter. TABLE 906.5.1 SIZE AND LENGTH OF SUMP VENTS DISCHARGE CAPACITY OF PUMP (gpm) MAXIMUM DEVELOP ED LENGTH OF VENT (feet) a Diameter of vent (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 10 No limit b No limit No limit No limit No limit No limit 20 270 No limit No limit No limit No limit No limit 40 72 160 No limit No limit No limit No limit 60 31 75 270 No limit No limit No limit 80 16 41 150 380 No limit No limit 100 10 c 25 97 250 No limit No limit 150 Not permitted 10 c 44 110 370 No limit 200 Not permitted Not permitted 20 60 210 No limit 250 Not permitted Not permitted 10 36 132 No limit 300 Not permitted Not permitted 10 c 22 88 380 400 Not permitted Not permitted Not permitted 10 c 44 210 500 Not permitted Not permitted Not permitted Not permitted 24 130 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 gallon per minute = 3.785 L/m. a. Developed length plus an appropriate allowance for entrance losses and friction due to fittings, changes in direction and dia meter. Suggested allowances shall be obtained from NBS Monograph 31 or other approved sources. An allowance of 50 percent of the de veloped length shall be assumed if a more precise value is not available. b. Actual values greater than 500 feet. c. Less than 10 feet. 906.5.2 Pneumatic sewage ejectors. The air pressure relief pipe from a pneumatic sewage ejector shall be con- nected to a n independent vent stack terminating as required for vent extensions through the roof. The relief pipe VENTS 9 - 6 2022 NEW YORK CITY PLUMBING CODE shall be sized to relieve air pressure inside the ejector to atmospheric pressure, but shall be not less than 1 1 / 2 inches (38 mm) in size. SECTION PC 907 VENTS FOR STACK OFFSETS 907.1 Vent for horizontal offset of drainage stack. Horizontal offsets of drainage stacks shall be vented where five or more branch intervals are located above the offset. The offset shall be vented by venting the upper section of the drainage stack and the lower section of the drainage stack. 907.2 Upper section. The upper section of the drainage stack shall be vented as a separate stack with a vent stack connection installed in accordance with Section 904.4. The offset shall be considered the base of the stack. 907.3 Lower section. The lower section of the drainage stack shall be vented by a yoke vent connecting between the offset and the next lower horizontal branch. The yoke vent connection shall be permitted to be a vertical extension of the drainage stack. The size of the yoke vent and connection shall be a minimum of the size required for the vent stack of the drainage stack. SECTION PC 908 RELIEF VENTS — STACKS OF MORE THAN 10 BRANCH INTERVALS 908.1 Where required. Soil and w aste stacks in buildings having more than 10 branch intervals shall be provided with a relief vent at each tenth interval installed, beginning with the top floor. 908.2 Size and connection. The size of the relief vent shall be equal to the size of the vent stack to which it connects. The lower end of each relief vent shall connect to the soil or waste stack through a wye below the horizontal branch serving the floor, and the upper end shall connect to the vent stack through a tee or inverted wye not less th an 3 feet (914 mm) above the floor. SECTION PC 909 FIXTURE VENTS 909.1 Distance of trap from vent. Each fixture trap shall have a protecting vent located so that the slope and the developed length in the fixture drain from the trap weir to the vent fitting are within the requirements set forth in Table 909.1. Exception: The developed length of the fixture drain from the trap weir to the vent fitting for self - siphoning fix- tures, such as water closets, shall not be limited. TABLE 909.1 MAXIMUM DISTANCE OF FIX TURE TRAP FROM VENT SIZE OF TRAP (inches) SLOPE (inch per foot) DISTANCE FROM TRAP (feet) 1 1 / 4 1 / 4 5 1 1 / 2 1 / 4 6 2 1 / 4 8 3 1 / 8 12 4 1 / 8 16 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 inch per foot = 83.3 mm/m. VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 7 909.2 Venting of fixture drains. The vent for a fixture drain, except where serving a fixture with integral traps, such as water closets, shall connect above the weir of the fixture trap being vented. 909.3 Crown vent. A vent shall not be installed within two pipe diameters of the trap weir . SECTION PC 910 INDIVIDUAL VENT 910.1 Individual vent permitted. Each trap and trapped fixture is permitted to be provided with an individual vent. The individual vent shall connect to the fixture drain of the trap or trapped fixture being vente d in accordance with section 909.1, but at a distance not to exceed 16 feet (4876 mm). 910.2 Floor drain vents. No vents will be required for piping serving floor drains when the floor drain is located not more than 15 feet (4572 mm) from the vented line to which it connects. SECTION PC 911 COMMON VENT 911.1 Individual vent as common vent. An individual vent is permitted to vent two traps or trapped fixtures as a common vent. The traps or trapped fixtures being common vented shall be located on the same floor level. 911.2 Connection at the same level. Where the fixture drains being common vented connect at the same level, the vent connection shall be at the interconnection of the fixture drains. Exception: Where wet vents are permitted by this code, the wet vent connection may be located downstream of the interconnection. 911.3 Connection at different levels. Where the fixture drains connect at different levels, the vent shall connect as a vertical extension of the vertical drain. The vertical drain p ipe connecting the two fixture drains shall be considered the vent for the lower fixture drain, and shall be sized in accordance with Table 911.3 . The upper fixture shall not be a water closet. TABLE 911.3 COMMON VENT SIZES PIPE SIZE (inches) MAXIMUM DISCH ARGE FROM UPPER FIXTURE DRAIN (dfu) 1 1 / 2 1 2 4 2 1 / 2 to 3 6 For SI: 1 inch = 25.4 mm. SECTION PC 912 WET VENTING 912.1 Horizontal wet vent permitted. Any combination of fixtures within one bathroom group located in the same room is permitted to be vented by a horizontal wet vent. The wet vent shall be considered the vent for the fixtures and shall extend from the connection of the dry vent along the direction of the flow in the drain pipe to the most down- stream fixture drain connection to the horizo ntal branch drain. Each wet - vented fixture drain shall connect inde- pendently to the horizontal wet vent. Only the fixtures within the bathroom groups shall connect to the wet - vented horizontal branch drain. Any additional fixtures shall discharge downstrea m of the horizontal wet vent. 912.1.1 Vertical wet vent permitted. Any combination of fixtures within one bathroom group is permitted to be vented by a vertical wet vent. The vertical wet vent shall be considered the vent for the fixtures and shall extend VENTS 9 - 8 2022 NEW YORK CITY PLUMBING CODE from the connection of the dry vent down to the lowest fixture drain connection. Each wet - vented fixture shall connect independently to the vertical wet vent. Fixture drains shall connect above or at the same elevation as the water closet fixture drain. Th e dry - vent connection to the vertical wet vent shall be an individual or common vent serving one or two fixtures. 912.2 Dry - vent connection. The required dry - vent connection for wet - vented systems shall comply with Sections 912.2.1 and 912.2.2. 912.2.1 Hor izontal wet vent. The dry - vent connection for a horizontal wet - vent system shall be an individual vent or a common vent for any bathroom group fixture, except an emergency floor drain. Where the dry - vent connects to a water closet fixture drain, the drain shall connect horizontally to the horizontal wet - vent system. Not more than one wet - vented fixture drain shall discharge upstream of the dry - vented fixture drain connection. 912.2.2 Vertical wet vent. The dry - vent connection for a vertical wet - vent system shall be an individual vent or common vent for the most upstream fixture drain. 912.3 Size. The dry vent serving the wet vent shall be sized based on the largest required diameter of pipe within the wet - vent system served by the dry vent. The wet vent shal l be of a size not less than that specified in Table 912.3, based on the fixture unit discharge to the wet vent. TABLE 912.3 WET VENT SIZE MINIMUM WET VENT PIPE SIZE (inches) MAXIMUM DRAINAGE FIXTURE UNIT LOAD (dfu) 2 4 2 1 / 2 6 3 12 For SI: 1 inch = 25.4 mm. SECTION PC 913 RESERVED SECTION PC 914 CIRCUIT VENTING 914.1 Circuit vent permitted. A maximum of eight fixtures connected to a horizontal branch drain shall be permitted to be circuit vented. Each fixture drain shall connect horizontally to the h orizontal branch being circuit vented. The horizontal branch drain shall be classified as a vent from the most downstream fixture drain connection to the most upstream fixture drain connection to the horizontal branch. 914.1.1 Multiple circuit - vented branc hes. Circuit - vented horizontal branch drains are permitted to be connected together. Each group of a maximum of eight fixtures shall be considered a separate circuit vent and shall conform to the requirements of this section. 914.2 Vent connection. The cir cuit vent connection shall be located between the two most upstream fixture drains. The vent shall connect to the horizontal branch and shall be installed in accordance with Section 905. The circuit vent pipe shall not receive the discharge of any soil or waste. 914.3 Slope and size of horizontal branch. The slope of the vent section of the horizontal branch drain shall be not greater than one unit vertical in 12 units horizontal (8.3 - percent slope). The entire length of the vent section of the horizontal branch drain shall be sized for the total drainage discharge to the branch. VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 9 914.3.1 Size of multiple circuit vent. Each separate circuit - vented horizontal branch that is interconnected shall be sized independently in accordance with Section 914.3 . The dow nstream circuit - vented horizontal branch shall be sized for the total discharge into the branch, including the upstream branches and the fixtures within the branch. 914.4 Relief vent. A relief vent shall be provided for circuit - vented horizontal branches r eceiving the discharge of four or more water closets and connecting to a drainage stack that receives the discharge of soil or waste from upper horizontal branches. 914.4.1 Connection and installation. The relief vent shall connect to the horizontal branch drain between the stack and the most downstream fixture drain of the circuit vent. The relief vent shall be installed in accordance with Section 905. 914.4.2 Fixture drain or branch. The relief vent is permitted to be a fixture drain or fixture branch for fixtures located within the same branch interval as the circuit - vented horizontal branch. The maximum discharge to a relief vent shall be four fixture units. 914.5 Additional fixtures. Fixtures, other than the circuit - vented fixtures, are permitted to dis charge to the horizontal branch drain. Such fixtures shall be located on the same floor as the circuit - vented fixtures and shall be either individ- ually or common vented. SECTION PC 915 COMBINATION WASTE AND VENT SYSTEM 915.1 Types of fixtures. A combination waste and vent system shall not serve fixtures other than floor drains, lava- tories and drinking fountains. Combination waste and vent systems shall not receive the discharge from a food waste disposer or clinical sink. 915.2 Installation. The c ombination waste and vent system shall be a horizontal piping system. The only vertical pipe of a combination waste and vent system shall be the connection between the fixture drain and the horizontal combi- nation waste and vent pipe. The vertical distance shall not exceed 8 feet (2438 mm). 915.2.1 Slope. The slope at a horizontal combination waste and vent pipe shall not exceed one - half unit vertical in 12 units horizontal (4 - percent slope) and shall not be less than indicated in Table 704.1. 915.2.2 Size a nd length. The size of a combination waste and vent pipe shall be not less than that indicated in Table 915.2.2. The horizontal length of a combination waste and vent system shall be unlimited. TABLE 915.2.2 SIZE OF COMBINATION WASTE AND VENT PIPE DIAMETER PIPE (inches) MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS (dfu) Connecting to a horizontal branch or stack Connecting to a building drain or building subdrain 2 3 4 2 1 / 2 6 26 3 12 31 4 20 50 5 160 250 6 360 575 For SI: 1 inch = 25.4 mm. CHAPTER 9 VENTS SECTION PC 901 GENERAL 901.1 Scope. The provisions of this chapter shall govern the materials, design, construction and installation of vent systems except for vent systems for methane and radon which shall be governed by this section . 901.1.1 Methane and radon venting. The design and mater ials used in the installation of the methane and radon vent systems shall be approved by the commissioner and shall comply with all applicable rules of the Fire De- partment. 901.2 Trap seal protection. The plumbing system shall be provided with a system of vent piping that will permit the admission or emission of air so that the seal of any fixture trap shall not be subjected to a pressure differential of more than 1 inch of water column (249 Pa). 901.2.1 Venting required. Traps and trapped fixtures shall be vented in accordance with one of the venting meth- ods specified in this chapter. 901.3 Chemical waste vent systems. The vent system for a chemical waste system shall be independent of the sanitary vent system and shall terminate separately through the roof to the outdoors . 901.4 Use limitations. The plumbing vent system shall not be utilized for purposes other than the venting of the plumbing system. 901.5 Tests. The vent system shall be tested in accordance with Section 312. 901.6 Engineered systems. Engin eered venting systems shall conform to the provisions of Section 919 . SECTION PC 902 MATERIALS 902.1 Vents. The materials and methods utilized for the construction and installation of venting systems shall comply with the applicable provisions of Section 7 02. 902.2 Sheet copper. Sheet copper for vent pipe flashings shall conform to ASTM B 152 and shall weigh not less than 8 ounces per square foot (2.5 kg/m 2 ). 902.3 Sheet lead. Sheet lead for vent pipe flashings shall weigh not less than 3 pounds per square foot (15 kg/m 2 ) for field - constructed flashings and not less than 2 1 / 2 pounds per square foot (12 kg/m 2 ) for prefabricated flashings. SECTION PC 903 VENT TERMINALS 903.1 Roof extension. Open vent pipes that extend through a roof shall be terminated not less than 24 inches (610 mm) above the roof. Where a roof is to be used for assembly or as a promenade, observation deck, sun bathing deck or similar purposes, open vent pipes shall terminate not less than 7 feet (2134 mm) above the roof. Ap proved vandal - resistant vent caps may be used. 903.2 Frost closure. Vent extensions through a roof or wall shall be not less than 4 inches (102 mm) in diameter. Any increase in the size of the vent shall be made not less than 1 foot (305 mm) inside the the rmal envelope of the building. 903.3 Flashings. The juncture of each vent pipe with the roof line shall be made water tight by an approved flashing. 903.4 Prohibited use. A vent terminal shall not be used for any purpose other than a vent terminal. 903.5 Location of vent terminal. Locations of vent terminals shall comply with Sections 903.5.1 and 903.5.2. VENTS 9 - 2 2022 NEW YORK CITY PLUMBING CODE 903.5.1 New vent terminals. An open vent terminal from a drainage system of the new or altered building shall not be located directly beneath any door, o perable window, or other air intake opening of the building or of an adjacent building, and any such vent terminal shall not be within 10 feet (3048 mm) horizontally of such an opening unless it is at least 3 feet (914 mm) above the top of such opening. Wh en the consent of the owner of an adjoining taller build - ing is obtained, the owner of the new or altered building shall be permitted to carry the new vent stack, with adequate support, to a level above the higher existing roof. 903.5.2 New openings. A doo r, operable window, or other air intake opening of the new or altered building shall not be located within 10 feet (3048 mm) horizontally from an open vent terminal from a drainage system of an existing adjacent building unless the existing terminal is at least 3 feet (914 mm) above such opening. Whenever necessary, the owner of the new building shall at his or her own expense, and with approval of the adjoining owner, offset the vent stack of the adjacent existing building to a distance of 10 feet (3048 mm ) or more from such openings, or shall extend such vent stack to a height of at least 3 feet (924 mm) above the topmost opening. 903.6 Reserved. 903.7 Reserved. SECTION PC 904 OUTDOOR VENT EXTENSIONS 904 .1 Required vent extension. The vent system serving each building drain shall have not less than one vent pipe that extends to the outdoors. 904. 1.1 Installation. The required vent shall be a dry vent that connects to the building drain or an extension of a drain that connects to the building drain. Such vent shall not be an island fixture vent as allowed by Section 916. 904.1.2 Size. The required vent shall be sized in accordance with Section 906.2 based on the required size of the building drain. 904.2 Vent stack required. A vent stack shall be required for every drainage stack that has three branch intervals or more . 904.3 Vent termination. Vent stacks or stack vents shall terminate outdoors above the roof or to the stack vent portion of the soil or waste stack, at least 6 inches (152 mm) above the flood level of the highest fixture connection discharging into the soil or waste stack. 904.4 Vent connection at base. Vent stacks shall connect to the base of the drainage stack. The vent stack shall co nnect at or below the lowest horizontal branch. Where the vent stack connects to the building drain, the connection shall be located downstream of the drainage stack and within a distance of 10 times the diameter of the drainage stack. 904.5 Vent headers. Stack vents and vent stacks connected into a common vent header at the top of the stacks and extending to the open air above the roof at one point shall be sized in accordance with the requirements of Section 906.1, but shall not be smaller than the smalle st stack vent . The number of fixture units shall be the sum of all fixture units on all stacks connected thereto, and the developed length shall be the longest vent length from the intersection at the base of the most distant stack to the vent terminal in the open air, as a direct extension of one stack. 904.6 Sub - stack connections. Where it is desired to terminate stacks at a point below the roof terminus of the main vent stack, the sub - stack may connect to the main vent stack provided the portion of the m ain vent stack above the connection is sized for the total fixture unit load connected thereto, and for the maximum developed length of the stack or sub - stack. SECTION PC 905 VENT CONNECTIONS AND GRADES 905.1 Connection. Individual , branch and circuit vents shall connect to a vent stack, stack vent, or extend to the open air above the roof . VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 3 905.2 Grade. Vent and branch vent pipes shall be so graded and connected as to drain back to the drainage pipe by gravity. 905.3 Vent connection to drainage system. Every dry vent connecting to a horizontal drain shall connect above the centerline of the horizontal drain pipe. 905.4 Reserved. 905.5 Height above fixtures. A connection between a vent pipe and a vent stack or stack vent shall be made at not less than 6 inches (152 mm) above the flood level rim of the highest fixture served by the vent. Horizontal vent pipes forming branch vents, relief vents or loop vents shall be located not less than 6 inches (152 mm) above the flood level rim of the highest fix ture served. 905.6 Vent for future fixtures. Where the drainage piping has been roughed - in for future fixtures, a rough - in con- nection for a vent shall be installed. The vent size shall be not less than one - half the diameter of the rough - in drain to be serv ed. The vent rough - in shall connect to the vent system, or shall be vented by other means as provided for in this chapter. The connection shall be identified to indicate that it is a vent. SECTION PC 906 VENT PIPE SIZING 906.1 Size of stack vents and vent stacks. The minimum required diameter of stack vents and vent stacks shall be determined from the developed length and the total of drainage fixture units connected thereto in accordance with Table 906.1, but in no case shall the diameter be less than one - half the diameter of the drain served or less than 1 1 / 4 inches (32 mm). TABLE 906.1 SIZE AND DEVELOPED LENGTH OF STACK VENTS AND VENT STACKS DIAMETER OF SOIL OR WASTE STACK (inches) TOTAL FIXTURE UNITS BEING VENTED (dfu) MAXIMUM DEVELOPED LENGTH OF VENT (f eet) a DIAMETER OF VENT (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 5 6 8 10 12 1 1 / 4 2 30 — — — — — — — — — — 1 1 / 2 8 50 150 1 1 / 2 10 30 100 2 12 — 75 200 — — — — — — — — 2 20 30 50 150 — 2 1 / 2 42 26 30 100 300 3 10 — 42 150 360 1,040 — — — — — — 3 21 32 110 270 810 3 53 27 94 230 680 3 102 — 25 86 210 620 — — — — — — 4 43 — 35 85 250 980 4 140 — 27 65 200 750 4 320 — — 23 55 170 640 — — — — — VENTS 9 - 4 2022 NEW YORK CITY PLUMBING CODE 4 540 21 50 150 580 — 5 190 28 82 320 990 5 490 — — — 21 63 250 760 — — — — 5 940 18 53 210 670 5 1,400 16 49 190 590 6 500 — — — — 33 130 400 1,000 — — — 6 1,100 — 26 100 310 780 6 2,000 — 22 84 260 660 6 2,900 — — — — 20 77 240 600 — — — 8 1,800 — 31 95 240 940 8 3,400 — 24 73 190 729 8 5,600 — — — — — 20 62 160 610 — — 8 7,600 18 56 140 560 — 10 4,000 — 31 78 310 960 10 7,200 — — — — — — 24 60 240 740 — 10 11,000 20 51 200 630 10 15,000 18 46 180 571 12 7,300 — — — — — — — 31 120 380 940 12 13,000 — 24 94 300 720 12 20,000 — 20 79 250 610 12 26,000 — — — — — — — 18 72 230 500 15 15,000 — 40 130 310 15 25,000 — 31 96 240 15 38,000 — — — — — — — — 26 81 200 15 50,000 24 74 180 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm. a. The developed length shall be measured from the vent connection to the open air. 906.2 Vents other than stack vents or vent stacks. The diameter of individual vents, branch vents, circuit vents and relief vents shall be at least one - half the required diameter of the drain served. The required size of the drain shall be determined in accordance with Table 710.1(2). Vent pipes shall not be less than 1 1 / 4 inches (32 mm) in diameter. Vents shall be sized in accordance with Table 906.1 utilizing the drainage fixture units and the corresponding VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 5 developed length. Relief vents for soil and waste stacks in buildings having more than 10 branch intervals shall be sized in accordance with Section 908.2. 906.3 Developed length. The developed length of individual, branch, circuit and relief vents shall be measured from the farthest point of vent connection to the drainage system to the point of connection to the vent stack, stack vent or termination outside of the building. 906.4 Multiple branch vents. Where multiple branch vents are connected to a common branch vent, the common branch vent shall be sized in accordance with this section based on the size of the co mmon horizontal drainage branch that is or would be required to serve the total drainage fixture unit load being vented. 906.5 Ejector vents. Ejector vent sizes shall be determined in accordance with Sections 906.5.1 and 906.5.2. 906.5.1 Sewage pumps and s ewage ejectors other than pneumatic. Drainage piping below sewer level shall be vented in the same manner as that of a gravity system. Building sump vent sizes for sumps with sewage pumps or sewage ejectors, other than pneumatic, shall be determined in acc ordance with Table 906.5.1. Where a building sump vent connects to a sanitary vent system, the sanitary branch vent shall be at least 3 inches (76 mm) in diameter. TABLE 906.5.1 SIZE AND LENGTH OF SUMP VENTS DISCHARGE CAPACITY OF PUMP (gpm) MAXIMUM DEVELOP ED LENGTH OF VENT (feet) a Diameter of vent (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 10 No limit b No limit No limit No limit No limit No limit 20 270 No limit No limit No limit No limit No limit 40 72 160 No limit No limit No limit No limit 60 31 75 270 No limit No limit No limit 80 16 41 150 380 No limit No limit 100 10 c 25 97 250 No limit No limit 150 Not permitted 10 c 44 110 370 No limit 200 Not permitted Not permitted 20 60 210 No limit 250 Not permitted Not permitted 10 36 132 No limit 300 Not permitted Not permitted 10 c 22 88 380 400 Not permitted Not permitted Not permitted 10 c 44 210 500 Not permitted Not permitted Not permitted Not permitted 24 130 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 gallon per minute = 3.785 L/m. a. Developed length plus an appropriate allowance for entrance losses and friction due to fittings, changes in direction and dia meter. Suggested allowances shall be obtained from NBS Monograph 31 or other approved sources. An allowance of 50 percent of the de veloped length shall be assumed if a more precise value is not available. b. Actual values greater than 500 feet. c. Less than 10 feet. 906.5.2 Pneumatic sewage ejectors. The air pressure relief pipe from a pneumatic sewage ejector shall be con- nected to a n independent vent stack terminating as required for vent extensions through the roof. The relief pipe VENTS 9 - 6 2022 NEW YORK CITY PLUMBING CODE shall be sized to relieve air pressure inside the ejector to atmospheric pressure, but shall be not less than 1 1 / 2 inches (38 mm) in size. SECTION PC 907 VENTS FOR STACK OFFSETS 907.1 Vent for horizontal offset of drainage stack. Horizontal offsets of drainage stacks shall be vented where five or more branch intervals are located above the offset. The offset shall be vented by venting the upper section of the drainage stack and the lower section of the drainage stack. 907.2 Upper section. The upper section of the drainage stack shall be vented as a separate stack with a vent stack connection installed in accordance with Section 904.4. The offset shall be considered the base of the stack. 907.3 Lower section. The lower section of the drainage stack shall be vented by a yoke vent connecting between the offset and the next lower horizontal branch. The yoke vent connection shall be permitted to be a vertical extension of the drainage stack. The size of the yoke vent and connection shall be a minimum of the size required for the vent stack of the drainage stack. SECTION PC 908 RELIEF VENTS — STACKS OF MORE THAN 10 BRANCH INTERVALS 908.1 Where required. Soil and w aste stacks in buildings having more than 10 branch intervals shall be provided with a relief vent at each tenth interval installed, beginning with the top floor. 908.2 Size and connection. The size of the relief vent shall be equal to the size of the vent stack to which it connects. The lower end of each relief vent shall connect to the soil or waste stack through a wye below the horizontal branch serving the floor, and the upper end shall connect to the vent stack through a tee or inverted wye not less th an 3 feet (914 mm) above the floor. SECTION PC 909 FIXTURE VENTS 909.1 Distance of trap from vent. Each fixture trap shall have a protecting vent located so that the slope and the developed length in the fixture drain from the trap weir to the vent fitting are within the requirements set forth in Table 909.1. Exception: The developed length of the fixture drain from the trap weir to the vent fitting for self - siphoning fix- tures, such as water closets, shall not be limited. TABLE 909.1 MAXIMUM DISTANCE OF FIX TURE TRAP FROM VENT SIZE OF TRAP (inches) SLOPE (inch per foot) DISTANCE FROM TRAP (feet) 1 1 / 4 1 / 4 5 1 1 / 2 1 / 4 6 2 1 / 4 8 3 1 / 8 12 4 1 / 8 16 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 inch per foot = 83.3 mm/m. VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 7 909.2 Venting of fixture drains. The vent for a fixture drain, except where serving a fixture with integral traps, such as water closets, shall connect above the weir of the fixture trap being vented. 909.3 Crown vent. A vent shall not be installed within two pipe diameters of the trap weir . SECTION PC 910 INDIVIDUAL VENT 910.1 Individual vent permitted. Each trap and trapped fixture is permitted to be provided with an individual vent. The individual vent shall connect to the fixture drain of the trap or trapped fixture being vente d in accordance with section 909.1, but at a distance not to exceed 16 feet (4876 mm). 910.2 Floor drain vents. No vents will be required for piping serving floor drains when the floor drain is located not more than 15 feet (4572 mm) from the vented line to which it connects. SECTION PC 911 COMMON VENT 911.1 Individual vent as common vent. An individual vent is permitted to vent two traps or trapped fixtures as a common vent. The traps or trapped fixtures being common vented shall be located on the same floor level. 911.2 Connection at the same level. Where the fixture drains being common vented connect at the same level, the vent connection shall be at the interconnection of the fixture drains. Exception: Where wet vents are permitted by this code, the wet vent connection may be located downstream of the interconnection. 911.3 Connection at different levels. Where the fixture drains connect at different levels, the vent shall connect as a vertical extension of the vertical drain. The vertical drain p ipe connecting the two fixture drains shall be considered the vent for the lower fixture drain, and shall be sized in accordance with Table 911.3 . The upper fixture shall not be a water closet. TABLE 911.3 COMMON VENT SIZES PIPE SIZE (inches) MAXIMUM DISCH ARGE FROM UPPER FIXTURE DRAIN (dfu) 1 1 / 2 1 2 4 2 1 / 2 to 3 6 For SI: 1 inch = 25.4 mm. SECTION PC 912 WET VENTING 912.1 Horizontal wet vent permitted. Any combination of fixtures within one bathroom group located in the same room is permitted to be vented by a horizontal wet vent. The wet vent shall be considered the vent for the fixtures and shall extend from the connection of the dry vent along the direction of the flow in the drain pipe to the most down- stream fixture drain connection to the horizo ntal branch drain. Each wet - vented fixture drain shall connect inde- pendently to the horizontal wet vent. Only the fixtures within the bathroom groups shall connect to the wet - vented horizontal branch drain. Any additional fixtures shall discharge downstrea m of the horizontal wet vent. 912.1.1 Vertical wet vent permitted. Any combination of fixtures within one bathroom group is permitted to be vented by a vertical wet vent. The vertical wet vent shall be considered the vent for the fixtures and shall extend VENTS 9 - 8 2022 NEW YORK CITY PLUMBING CODE from the connection of the dry vent down to the lowest fixture drain connection. Each wet - vented fixture shall connect independently to the vertical wet vent. Fixture drains shall connect above or at the same elevation as the water closet fixture drain. Th e dry - vent connection to the vertical wet vent shall be an individual or common vent serving one or two fixtures. 912.2 Dry - vent connection. The required dry - vent connection for wet - vented systems shall comply with Sections 912.2.1 and 912.2.2. 912.2.1 Hor izontal wet vent. The dry - vent connection for a horizontal wet - vent system shall be an individual vent or a common vent for any bathroom group fixture, except an emergency floor drain. Where the dry - vent connects to a water closet fixture drain, the drain shall connect horizontally to the horizontal wet - vent system. Not more than one wet - vented fixture drain shall discharge upstream of the dry - vented fixture drain connection. 912.2.2 Vertical wet vent. The dry - vent connection for a vertical wet - vent system shall be an individual vent or common vent for the most upstream fixture drain. 912.3 Size. The dry vent serving the wet vent shall be sized based on the largest required diameter of pipe within the wet - vent system served by the dry vent. The wet vent shal l be of a size not less than that specified in Table 912.3, based on the fixture unit discharge to the wet vent. TABLE 912.3 WET VENT SIZE MINIMUM WET VENT PIPE SIZE (inches) MAXIMUM DRAINAGE FIXTURE UNIT LOAD (dfu) 2 4 2 1 / 2 6 3 12 For SI: 1 inch = 25.4 mm. SECTION PC 913 RESERVED SECTION PC 914 CIRCUIT VENTING 914.1 Circuit vent permitted. A maximum of eight fixtures connected to a horizontal branch drain shall be permitted to be circuit vented. Each fixture drain shall connect horizontally to the h orizontal branch being circuit vented. The horizontal branch drain shall be classified as a vent from the most downstream fixture drain connection to the most upstream fixture drain connection to the horizontal branch. 914.1.1 Multiple circuit - vented branc hes. Circuit - vented horizontal branch drains are permitted to be connected together. Each group of a maximum of eight fixtures shall be considered a separate circuit vent and shall conform to the requirements of this section. 914.2 Vent connection. The cir cuit vent connection shall be located between the two most upstream fixture drains. The vent shall connect to the horizontal branch and shall be installed in accordance with Section 905. The circuit vent pipe shall not receive the discharge of any soil or waste. 914.3 Slope and size of horizontal branch. The slope of the vent section of the horizontal branch drain shall be not greater than one unit vertical in 12 units horizontal (8.3 - percent slope). The entire length of the vent section of the horizontal branch drain shall be sized for the total drainage discharge to the branch. VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 9 914.3.1 Size of multiple circuit vent. Each separate circuit - vented horizontal branch that is interconnected shall be sized independently in accordance with Section 914.3 . The dow nstream circuit - vented horizontal branch shall be sized for the total discharge into the branch, including the upstream branches and the fixtures within the branch. 914.4 Relief vent. A relief vent shall be provided for circuit - vented horizontal branches r eceiving the discharge of four or more water closets and connecting to a drainage stack that receives the discharge of soil or waste from upper horizontal branches. 914.4.1 Connection and installation. The relief vent shall connect to the horizontal branch drain between the stack and the most downstream fixture drain of the circuit vent. The relief vent shall be installed in accordance with Section 905. 914.4.2 Fixture drain or branch. The relief vent is permitted to be a fixture drain or fixture branch for fixtures located within the same branch interval as the circuit - vented horizontal branch. The maximum discharge to a relief vent shall be four fixture units. 914.5 Additional fixtures. Fixtures, other than the circuit - vented fixtures, are permitted to dis charge to the horizontal branch drain. Such fixtures shall be located on the same floor as the circuit - vented fixtures and shall be either individ- ually or common vented. SECTION PC 915 COMBINATION WASTE AND VENT SYSTEM 915.1 Types of fixtures. A combination waste and vent system shall not serve fixtures other than floor drains, lava- tories and drinking fountains. Combination waste and vent systems shall not receive the discharge from a food waste disposer or clinical sink. 915.2 Installation. The c ombination waste and vent system shall be a horizontal piping system. The only vertical pipe of a combination waste and vent system shall be the connection between the fixture drain and the horizontal combi- nation waste and vent pipe. The vertical distance shall not exceed 8 feet (2438 mm). 915.2.1 Slope. The slope at a horizontal combination waste and vent pipe shall not exceed one - half unit vertical in 12 units horizontal (4 - percent slope) and shall not be less than indicated in Table 704.1. 915.2.2 Size a nd length. The size of a combination waste and vent pipe shall be not less than that indicated in Table 915.2.2. The horizontal length of a combination waste and vent system shall be unlimited. TABLE 915.2.2 SIZE OF COMBINATION WASTE AND VENT PIPE DIAMETER PIPE (inches) MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS (dfu) Connecting to a horizontal branch or stack Connecting to a building drain or building subdrain 2 3 4 2 1 / 2 6 26 3 12 31 4 20 50 5 160 250 6 360 575 For SI: 1 inch = 25.4 mm. CHAPTER 9 VENTS SECTION PC 901 GENERAL 901.1 Scope. The provisions of this chapter shall govern the materials, design, construction and installation of vent systems except for vent systems for methane and radon which shall be governed by this section . 901.1.1 Methane and radon venting. The design and mater ials used in the installation of the methane and radon vent systems shall be approved by the commissioner and shall comply with all applicable rules of the Fire De- partment. 901.2 Trap seal protection. The plumbing system shall be provided with a system of vent piping that will permit the admission or emission of air so that the seal of any fixture trap shall not be subjected to a pressure differential of more than 1 inch of water column (249 Pa). 901.2.1 Venting required. Traps and trapped fixtures shall be vented in accordance with one of the venting meth- ods specified in this chapter. 901.3 Chemical waste vent systems. The vent system for a chemical waste system shall be independent of the sanitary vent system and shall terminate separately through the roof to the outdoors . 901.4 Use limitations. The plumbing vent system shall not be utilized for purposes other than the venting of the plumbing system. 901.5 Tests. The vent system shall be tested in accordance with Section 312. 901.6 Engineered systems. Engin eered venting systems shall conform to the provisions of Section 919 . SECTION PC 902 MATERIALS 902.1 Vents. The materials and methods utilized for the construction and installation of venting systems shall comply with the applicable provisions of Section 7 02. 902.2 Sheet copper. Sheet copper for vent pipe flashings shall conform to ASTM B 152 and shall weigh not less than 8 ounces per square foot (2.5 kg/m 2 ). 902.3 Sheet lead. Sheet lead for vent pipe flashings shall weigh not less than 3 pounds per square foot (15 kg/m 2 ) for field - constructed flashings and not less than 2 1 / 2 pounds per square foot (12 kg/m 2 ) for prefabricated flashings. SECTION PC 903 VENT TERMINALS 903.1 Roof extension. Open vent pipes that extend through a roof shall be terminated not less than 24 inches (610 mm) above the roof. Where a roof is to be used for assembly or as a promenade, observation deck, sun bathing deck or similar purposes, open vent pipes shall terminate not less than 7 feet (2134 mm) above the roof. Ap proved vandal - resistant vent caps may be used. 903.2 Frost closure. Vent extensions through a roof or wall shall be not less than 4 inches (102 mm) in diameter. Any increase in the size of the vent shall be made not less than 1 foot (305 mm) inside the the rmal envelope of the building. 903.3 Flashings. The juncture of each vent pipe with the roof line shall be made water tight by an approved flashing. 903.4 Prohibited use. A vent terminal shall not be used for any purpose other than a vent terminal. 903.5 Location of vent terminal. Locations of vent terminals shall comply with Sections 903.5.1 and 903.5.2. VENTS 9 - 2 2022 NEW YORK CITY PLUMBING CODE 903.5.1 New vent terminals. An open vent terminal from a drainage system of the new or altered building shall not be located directly beneath any door, o perable window, or other air intake opening of the building or of an adjacent building, and any such vent terminal shall not be within 10 feet (3048 mm) horizontally of such an opening unless it is at least 3 feet (914 mm) above the top of such opening. Wh en the consent of the owner of an adjoining taller build - ing is obtained, the owner of the new or altered building shall be permitted to carry the new vent stack, with adequate support, to a level above the higher existing roof. 903.5.2 New openings. A doo r, operable window, or other air intake opening of the new or altered building shall not be located within 10 feet (3048 mm) horizontally from an open vent terminal from a drainage system of an existing adjacent building unless the existing terminal is at least 3 feet (914 mm) above such opening. Whenever necessary, the owner of the new building shall at his or her own expense, and with approval of the adjoining owner, offset the vent stack of the adjacent existing building to a distance of 10 feet (3048 mm ) or more from such openings, or shall extend such vent stack to a height of at least 3 feet (924 mm) above the topmost opening. 903.6 Reserved. 903.7 Reserved. SECTION PC 904 OUTDOOR VENT EXTENSIONS 904 .1 Required vent extension. The vent system serving each building drain shall have not less than one vent pipe that extends to the outdoors. 904. 1.1 Installation. The required vent shall be a dry vent that connects to the building drain or an extension of a drain that connects to the building drain. Such vent shall not be an island fixture vent as allowed by Section 916. 904.1.2 Size. The required vent shall be sized in accordance with Section 906.2 based on the required size of the building drain. 904.2 Vent stack required. A vent stack shall be required for every drainage stack that has three branch intervals or more . 904.3 Vent termination. Vent stacks or stack vents shall terminate outdoors above the roof or to the stack vent portion of the soil or waste stack, at least 6 inches (152 mm) above the flood level of the highest fixture connection discharging into the soil or waste stack. 904.4 Vent connection at base. Vent stacks shall connect to the base of the drainage stack. The vent stack shall co nnect at or below the lowest horizontal branch. Where the vent stack connects to the building drain, the connection shall be located downstream of the drainage stack and within a distance of 10 times the diameter of the drainage stack. 904.5 Vent headers. Stack vents and vent stacks connected into a common vent header at the top of the stacks and extending to the open air above the roof at one point shall be sized in accordance with the requirements of Section 906.1, but shall not be smaller than the smalle st stack vent . The number of fixture units shall be the sum of all fixture units on all stacks connected thereto, and the developed length shall be the longest vent length from the intersection at the base of the most distant stack to the vent terminal in the open air, as a direct extension of one stack. 904.6 Sub - stack connections. Where it is desired to terminate stacks at a point below the roof terminus of the main vent stack, the sub - stack may connect to the main vent stack provided the portion of the m ain vent stack above the connection is sized for the total fixture unit load connected thereto, and for the maximum developed length of the stack or sub - stack. SECTION PC 905 VENT CONNECTIONS AND GRADES 905.1 Connection. Individual , branch and circuit vents shall connect to a vent stack, stack vent, or extend to the open air above the roof . VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 3 905.2 Grade. Vent and branch vent pipes shall be so graded and connected as to drain back to the drainage pipe by gravity. 905.3 Vent connection to drainage system. Every dry vent connecting to a horizontal drain shall connect above the centerline of the horizontal drain pipe. 905.4 Reserved. 905.5 Height above fixtures. A connection between a vent pipe and a vent stack or stack vent shall be made at not less than 6 inches (152 mm) above the flood level rim of the highest fixture served by the vent. Horizontal vent pipes forming branch vents, relief vents or loop vents shall be located not less than 6 inches (152 mm) above the flood level rim of the highest fix ture served. 905.6 Vent for future fixtures. Where the drainage piping has been roughed - in for future fixtures, a rough - in con- nection for a vent shall be installed. The vent size shall be not less than one - half the diameter of the rough - in drain to be serv ed. The vent rough - in shall connect to the vent system, or shall be vented by other means as provided for in this chapter. The connection shall be identified to indicate that it is a vent. SECTION PC 906 VENT PIPE SIZING 906.1 Size of stack vents and vent stacks. The minimum required diameter of stack vents and vent stacks shall be determined from the developed length and the total of drainage fixture units connected thereto in accordance with Table 906.1, but in no case shall the diameter be less than one - half the diameter of the drain served or less than 1 1 / 4 inches (32 mm). TABLE 906.1 SIZE AND DEVELOPED LENGTH OF STACK VENTS AND VENT STACKS DIAMETER OF SOIL OR WASTE STACK (inches) TOTAL FIXTURE UNITS BEING VENTED (dfu) MAXIMUM DEVELOPED LENGTH OF VENT (f eet) a DIAMETER OF VENT (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 5 6 8 10 12 1 1 / 4 2 30 — — — — — — — — — — 1 1 / 2 8 50 150 1 1 / 2 10 30 100 2 12 — 75 200 — — — — — — — — 2 20 30 50 150 — 2 1 / 2 42 26 30 100 300 3 10 — 42 150 360 1,040 — — — — — — 3 21 32 110 270 810 3 53 27 94 230 680 3 102 — 25 86 210 620 — — — — — — 4 43 — 35 85 250 980 4 140 — 27 65 200 750 4 320 — — 23 55 170 640 — — — — — VENTS 9 - 4 2022 NEW YORK CITY PLUMBING CODE 4 540 21 50 150 580 — 5 190 28 82 320 990 5 490 — — — 21 63 250 760 — — — — 5 940 18 53 210 670 5 1,400 16 49 190 590 6 500 — — — — 33 130 400 1,000 — — — 6 1,100 — 26 100 310 780 6 2,000 — 22 84 260 660 6 2,900 — — — — 20 77 240 600 — — — 8 1,800 — 31 95 240 940 8 3,400 — 24 73 190 729 8 5,600 — — — — — 20 62 160 610 — — 8 7,600 18 56 140 560 — 10 4,000 — 31 78 310 960 10 7,200 — — — — — — 24 60 240 740 — 10 11,000 20 51 200 630 10 15,000 18 46 180 571 12 7,300 — — — — — — — 31 120 380 940 12 13,000 — 24 94 300 720 12 20,000 — 20 79 250 610 12 26,000 — — — — — — — 18 72 230 500 15 15,000 — 40 130 310 15 25,000 — 31 96 240 15 38,000 — — — — — — — — 26 81 200 15 50,000 24 74 180 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm. a. The developed length shall be measured from the vent connection to the open air. 906.2 Vents other than stack vents or vent stacks. The diameter of individual vents, branch vents, circuit vents and relief vents shall be at least one - half the required diameter of the drain served. The required size of the drain shall be determined in accordance with Table 710.1(2). Vent pipes shall not be less than 1 1 / 4 inches (32 mm) in diameter. Vents shall be sized in accordance with Table 906.1 utilizing the drainage fixture units and the corresponding VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 5 developed length. Relief vents for soil and waste stacks in buildings having more than 10 branch intervals shall be sized in accordance with Section 908.2. 906.3 Developed length. The developed length of individual, branch, circuit and relief vents shall be measured from the farthest point of vent connection to the drainage system to the point of connection to the vent stack, stack vent or termination outside of the building. 906.4 Multiple branch vents. Where multiple branch vents are connected to a common branch vent, the common branch vent shall be sized in accordance with this section based on the size of the co mmon horizontal drainage branch that is or would be required to serve the total drainage fixture unit load being vented. 906.5 Ejector vents. Ejector vent sizes shall be determined in accordance with Sections 906.5.1 and 906.5.2. 906.5.1 Sewage pumps and s ewage ejectors other than pneumatic. Drainage piping below sewer level shall be vented in the same manner as that of a gravity system. Building sump vent sizes for sumps with sewage pumps or sewage ejectors, other than pneumatic, shall be determined in acc ordance with Table 906.5.1. Where a building sump vent connects to a sanitary vent system, the sanitary branch vent shall be at least 3 inches (76 mm) in diameter. TABLE 906.5.1 SIZE AND LENGTH OF SUMP VENTS DISCHARGE CAPACITY OF PUMP (gpm) MAXIMUM DEVELOP ED LENGTH OF VENT (feet) a Diameter of vent (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 10 No limit b No limit No limit No limit No limit No limit 20 270 No limit No limit No limit No limit No limit 40 72 160 No limit No limit No limit No limit 60 31 75 270 No limit No limit No limit 80 16 41 150 380 No limit No limit 100 10 c 25 97 250 No limit No limit 150 Not permitted 10 c 44 110 370 No limit 200 Not permitted Not permitted 20 60 210 No limit 250 Not permitted Not permitted 10 36 132 No limit 300 Not permitted Not permitted 10 c 22 88 380 400 Not permitted Not permitted Not permitted 10 c 44 210 500 Not permitted Not permitted Not permitted Not permitted 24 130 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 gallon per minute = 3.785 L/m. a. Developed length plus an appropriate allowance for entrance losses and friction due to fittings, changes in direction and dia meter. Suggested allowances shall be obtained from NBS Monograph 31 or other approved sources. An allowance of 50 percent of the de veloped length shall be assumed if a more precise value is not available. b. Actual values greater than 500 feet. c. Less than 10 feet. 906.5.2 Pneumatic sewage ejectors. The air pressure relief pipe from a pneumatic sewage ejector shall be con- nected to a n independent vent stack terminating as required for vent extensions through the roof. The relief pipe VENTS 9 - 6 2022 NEW YORK CITY PLUMBING CODE shall be sized to relieve air pressure inside the ejector to atmospheric pressure, but shall be not less than 1 1 / 2 inches (38 mm) in size. SECTION PC 907 VENTS FOR STACK OFFSETS 907.1 Vent for horizontal offset of drainage stack. Horizontal offsets of drainage stacks shall be vented where five or more branch intervals are located above the offset. The offset shall be vented by venting the upper section of the drainage stack and the lower section of the drainage stack. 907.2 Upper section. The upper section of the drainage stack shall be vented as a separate stack with a vent stack connection installed in accordance with Section 904.4. The offset shall be considered the base of the stack. 907.3 Lower section. The lower section of the drainage stack shall be vented by a yoke vent connecting between the offset and the next lower horizontal branch. The yoke vent connection shall be permitted to be a vertical extension of the drainage stack. The size of the yoke vent and connection shall be a minimum of the size required for the vent stack of the drainage stack. SECTION PC 908 RELIEF VENTS — STACKS OF MORE THAN 10 BRANCH INTERVALS 908.1 Where required. Soil and w aste stacks in buildings having more than 10 branch intervals shall be provided with a relief vent at each tenth interval installed, beginning with the top floor. 908.2 Size and connection. The size of the relief vent shall be equal to the size of the vent stack to which it connects. The lower end of each relief vent shall connect to the soil or waste stack through a wye below the horizontal branch serving the floor, and the upper end shall connect to the vent stack through a tee or inverted wye not less th an 3 feet (914 mm) above the floor. SECTION PC 909 FIXTURE VENTS 909.1 Distance of trap from vent. Each fixture trap shall have a protecting vent located so that the slope and the developed length in the fixture drain from the trap weir to the vent fitting are within the requirements set forth in Table 909.1. Exception: The developed length of the fixture drain from the trap weir to the vent fitting for self - siphoning fix- tures, such as water closets, shall not be limited. TABLE 909.1 MAXIMUM DISTANCE OF FIX TURE TRAP FROM VENT SIZE OF TRAP (inches) SLOPE (inch per foot) DISTANCE FROM TRAP (feet) 1 1 / 4 1 / 4 5 1 1 / 2 1 / 4 6 2 1 / 4 8 3 1 / 8 12 4 1 / 8 16 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 inch per foot = 83.3 mm/m. VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 7 909.2 Venting of fixture drains. The vent for a fixture drain, except where serving a fixture with integral traps, such as water closets, shall connect above the weir of the fixture trap being vented. 909.3 Crown vent. A vent shall not be installed within two pipe diameters of the trap weir . SECTION PC 910 INDIVIDUAL VENT 910.1 Individual vent permitted. Each trap and trapped fixture is permitted to be provided with an individual vent. The individual vent shall connect to the fixture drain of the trap or trapped fixture being vente d in accordance with section 909.1, but at a distance not to exceed 16 feet (4876 mm). 910.2 Floor drain vents. No vents will be required for piping serving floor drains when the floor drain is located not more than 15 feet (4572 mm) from the vented line to which it connects. SECTION PC 911 COMMON VENT 911.1 Individual vent as common vent. An individual vent is permitted to vent two traps or trapped fixtures as a common vent. The traps or trapped fixtures being common vented shall be located on the same floor level. 911.2 Connection at the same level. Where the fixture drains being common vented connect at the same level, the vent connection shall be at the interconnection of the fixture drains. Exception: Where wet vents are permitted by this code, the wet vent connection may be located downstream of the interconnection. 911.3 Connection at different levels. Where the fixture drains connect at different levels, the vent shall connect as a vertical extension of the vertical drain. The vertical drain p ipe connecting the two fixture drains shall be considered the vent for the lower fixture drain, and shall be sized in accordance with Table 911.3 . The upper fixture shall not be a water closet. TABLE 911.3 COMMON VENT SIZES PIPE SIZE (inches) MAXIMUM DISCH ARGE FROM UPPER FIXTURE DRAIN (dfu) 1 1 / 2 1 2 4 2 1 / 2 to 3 6 For SI: 1 inch = 25.4 mm. SECTION PC 912 WET VENTING 912.1 Horizontal wet vent permitted. Any combination of fixtures within one bathroom group located in the same room is permitted to be vented by a horizontal wet vent. The wet vent shall be considered the vent for the fixtures and shall extend from the connection of the dry vent along the direction of the flow in the drain pipe to the most down- stream fixture drain connection to the horizo ntal branch drain. Each wet - vented fixture drain shall connect inde- pendently to the horizontal wet vent. Only the fixtures within the bathroom groups shall connect to the wet - vented horizontal branch drain. Any additional fixtures shall discharge downstrea m of the horizontal wet vent. 912.1.1 Vertical wet vent permitted. Any combination of fixtures within one bathroom group is permitted to be vented by a vertical wet vent. The vertical wet vent shall be considered the vent for the fixtures and shall extend VENTS 9 - 8 2022 NEW YORK CITY PLUMBING CODE from the connection of the dry vent down to the lowest fixture drain connection. Each wet - vented fixture shall connect independently to the vertical wet vent. Fixture drains shall connect above or at the same elevation as the water closet fixture drain. Th e dry - vent connection to the vertical wet vent shall be an individual or common vent serving one or two fixtures. 912.2 Dry - vent connection. The required dry - vent connection for wet - vented systems shall comply with Sections 912.2.1 and 912.2.2. 912.2.1 Hor izontal wet vent. The dry - vent connection for a horizontal wet - vent system shall be an individual vent or a common vent for any bathroom group fixture, except an emergency floor drain. Where the dry - vent connects to a water closet fixture drain, the drain shall connect horizontally to the horizontal wet - vent system. Not more than one wet - vented fixture drain shall discharge upstream of the dry - vented fixture drain connection. 912.2.2 Vertical wet vent. The dry - vent connection for a vertical wet - vent system shall be an individual vent or common vent for the most upstream fixture drain. 912.3 Size. The dry vent serving the wet vent shall be sized based on the largest required diameter of pipe within the wet - vent system served by the dry vent. The wet vent shal l be of a size not less than that specified in Table 912.3, based on the fixture unit discharge to the wet vent. TABLE 912.3 WET VENT SIZE MINIMUM WET VENT PIPE SIZE (inches) MAXIMUM DRAINAGE FIXTURE UNIT LOAD (dfu) 2 4 2 1 / 2 6 3 12 For SI: 1 inch = 25.4 mm. SECTION PC 913 RESERVED SECTION PC 914 CIRCUIT VENTING 914.1 Circuit vent permitted. A maximum of eight fixtures connected to a horizontal branch drain shall be permitted to be circuit vented. Each fixture drain shall connect horizontally to the h orizontal branch being circuit vented. The horizontal branch drain shall be classified as a vent from the most downstream fixture drain connection to the most upstream fixture drain connection to the horizontal branch. 914.1.1 Multiple circuit - vented branc hes. Circuit - vented horizontal branch drains are permitted to be connected together. Each group of a maximum of eight fixtures shall be considered a separate circuit vent and shall conform to the requirements of this section. 914.2 Vent connection. The cir cuit vent connection shall be located between the two most upstream fixture drains. The vent shall connect to the horizontal branch and shall be installed in accordance with Section 905. The circuit vent pipe shall not receive the discharge of any soil or waste. 914.3 Slope and size of horizontal branch. The slope of the vent section of the horizontal branch drain shall be not greater than one unit vertical in 12 units horizontal (8.3 - percent slope). The entire length of the vent section of the horizontal branch drain shall be sized for the total drainage discharge to the branch. VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 9 914.3.1 Size of multiple circuit vent. Each separate circuit - vented horizontal branch that is interconnected shall be sized independently in accordance with Section 914.3 . The dow nstream circuit - vented horizontal branch shall be sized for the total discharge into the branch, including the upstream branches and the fixtures within the branch. 914.4 Relief vent. A relief vent shall be provided for circuit - vented horizontal branches r eceiving the discharge of four or more water closets and connecting to a drainage stack that receives the discharge of soil or waste from upper horizontal branches. 914.4.1 Connection and installation. The relief vent shall connect to the horizontal branch drain between the stack and the most downstream fixture drain of the circuit vent. The relief vent shall be installed in accordance with Section 905. 914.4.2 Fixture drain or branch. The relief vent is permitted to be a fixture drain or fixture branch for fixtures located within the same branch interval as the circuit - vented horizontal branch. The maximum discharge to a relief vent shall be four fixture units. 914.5 Additional fixtures. Fixtures, other than the circuit - vented fixtures, are permitted to dis charge to the horizontal branch drain. Such fixtures shall be located on the same floor as the circuit - vented fixtures and shall be either individ- ually or common vented. SECTION PC 915 COMBINATION WASTE AND VENT SYSTEM 915.1 Types of fixtures. A combination waste and vent system shall not serve fixtures other than floor drains, lava- tories and drinking fountains. Combination waste and vent systems shall not receive the discharge from a food waste disposer or clinical sink. 915.2 Installation. The c ombination waste and vent system shall be a horizontal piping system. The only vertical pipe of a combination waste and vent system shall be the connection between the fixture drain and the horizontal combi- nation waste and vent pipe. The vertical distance shall not exceed 8 feet (2438 mm). 915.2.1 Slope. The slope at a horizontal combination waste and vent pipe shall not exceed one - half unit vertical in 12 units horizontal (4 - percent slope) and shall not be less than indicated in Table 704.1. 915.2.2 Size a nd length. The size of a combination waste and vent pipe shall be not less than that indicated in Table 915.2.2. The horizontal length of a combination waste and vent system shall be unlimited. TABLE 915.2.2 SIZE OF COMBINATION WASTE AND VENT PIPE DIAMETER PIPE (inches) MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS (dfu) Connecting to a horizontal branch or stack Connecting to a building drain or building subdrain 2 3 4 2 1 / 2 6 26 3 12 31 4 20 50 5 160 250 6 360 575 For SI: 1 inch = 25.4 mm. VENTS 9 - 10 2022 NEW YORK CITY PLUMBING CODE 915.2.3 Connection. The combination waste and vent system shall be provided with a dry vent connected at any point within the system or the system shall connect to a horizontal drain that serves vented fixtures located on the same floor . Combination waste and vent systems connecting to building drains receiving only the discharge from one or more stacks shall be provided with a dry vent. The vent connection to the combination waste and vent pipe shall extend vertically to a point not less than 6 inches (152 mm) above the flood level rim of the highest fixture being vented before offsetting horizontally. 915.2.4 Vent size. The vent shall be sized for the total drainage fixture unit load in accordance with Section 906.2 . 915.2.5 Fixture branch or drain. The fi xture branch or fixture drain shall connect to the combination waste and vent within a distance specified in Table 909.1. The combination waste and vent pipe shall be considered the vent for the fixture . SECTION PC 916 ISLAND FIXTURE VENTING 916.1 Limitati on. Island fixture venting shall not be permitted for fixtures other than sinks and lavatories. Residential kitchen sinks with a dishwasher waste connection, a food waste disposer , or both, in combination with the kitchen sink waste, shall be permitted to be vented in accordance with this section. 916.2 Vent connection. The island fixture vent shall connect to the fixture drain as required for an individual or common vent. The vent shall rise vertically to above the drainage outlet of the fixture being vent ed before offsetting horizontally or vertically downward. The vent or branch vent for multiple island fixture vents shall extend to a point not less than 6 inches (152 mm) above the highest island fixture being vented before connecting to the outside vent terminal. 916.3 Vent installation below the fixture flood level rim. The vent located below the flood level rim of the fixture being vented shall be installed as required for drainage piping in accordance with Chapter 7, except for sizing. The vent shall b e sized in accordance with Section 906.2 . The lowest point of the island fixture vent shall connect full size to the drainage system. The connection shall be to a vertical drain pipe or to the top half of a horizontal drain pipe. Cleanouts shall be provided in the island fixture vent to permit rodding of all vent piping located below the flood level rim of the fixtures. Rodding in both directions shall be permitted through a cleanout. SECTION PC 917 RESERVED SECTION PC 918 RESERVED SECTION PC 919 ENG INEERED VENT SYSTEMS 919.1 General. Engineered vent systems shall comply with this section and Section 28 - 113.2.2 of the Administrative Code . 919.2 Individual branch fixture and individual fixture header vents. The maximum developed length of individual fi xture vents to vent branches and vent headers shall be determined in accordance with Table 919.2 for the minimum pipe diameters at the indicated vent airflow rates. The individual vent airflow rate shall be determined in accordance with the following: Q h,b = N n,b Q ν (Equation 9 - 1) For SI: Q h , b = N n , b Q ν (0.4719 L/s) where: VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 11 N n , b = Number of fixtures per header (or vent branch) ÷ total number of fixtures connected to vent stack. Q h , b = Vent branch or vent header airflow rate (cfm). Q ν = Total vent stack airflow rate (cfm). Q ν (gpm) = 27.8 r s 2/3 (1 – rs ) D 8/3 Q ν (cfm) = 0.134 Q ν (gpm) where: D = Drainage stack diameter (inches). Q w = Design discharge load (gpm). r s = Waste water flow area to total area. = Q w / 27.8 D 8/3 Individual vent airflow rates are obtained by equally distributing Q h,b into one - half the total number of fixtures on the branch or header for more than two fixtures; for an odd number of total fixtures, decrease by one; for one fixture, apply the full value of Q h, b . Individual vent developed length shall be increased by 20 percent of the distance from the vent stack to the fixture vent connecti on on the vent branch or header. TABLE 919.2 MINIMUM DIAMETER AND MAXIMUM LENGTH OF INDIVIDUAL BRANCH FIXTURE VENTS AND INDIVIDUAL FIXTURE HEADER VENTS FOR SMOOTH PIPES DIAMETER OF VENT PIPE (inches) INDIVIDUAL VENT AIRFLOW RATE (cubic feet per minute) Maximum developed length of vent (feet) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 1 / 2 95 25 13 8 5 4 3 2 1 1 1 1 1 1 1 1 1 1 1 1 3 / 4 100 88 47 30 20 15 10 9 7 6 5 4 3 3 3 2 2 2 2 1 1 — — 100 94 65 48 37 29 24 20 17 14 12 11 9 8 7 7 6 6 1 1 / 4 — — — — — — — 100 87 73 62 53 46 40 36 32 29 26 23 21 1 1 / 2 — — — — — — — — — — — 100 96 84 75 65 60 54 49 45 2 — — — — — — — — — — — — — — — — — — — 100 For SI: 1 inch = 25.4 mm, 1 cubic foot per minute = 0.4719 L/s, 1 foot = 304.8 mm. 919.3 A licensed professional engineer shall certify design. An engineer shall also inspect and certify the system upon completion of the system. SECTION PC 920 COMPUTERIZED VENT DESIGN 920.1 Design of vent system. The sizing, design and layout of the vent system shall be permitted to be determined by computer program design methods which shall be approved by the commissioner to insure compliance with the minimum standards of this code . 920.2 System capacity. The vent system shall be based on the air capacit y requirements of the drainage system under a peak load condition. VENTS 9 - 12 2022 NEW YORK CITY PLUMBING CODE 920.3 Design shall be certified by a licensed professional engineer. An engineer shall also inspect and certify the system upon completion of the system.03.5.1 New vent terminals. An open vent terminal from a drainage system of the new or altered building shall not be located directly beneath any door, o perable window, or other air intake opening of the building or of an adjacent building, and any such vent terminal shall not be within 10 feet (3048 mm) horizontally of such an opening unless it is at least 3 feet (914 mm) above the top of such opening. Wh en the consent of the owner of an adjoining taller build - ing is obtained, the owner of the new or altered building shall be permitted to carry the new vent stack, with adequate support, to a level above the higher existing roof. 903.5.2 New openings. A doo r, operable window, or other air intake opening of the new or altered building shall not be located within 10 feet (3048 mm) horizontally from an open vent terminal from a drainage system of an existing adjacent building unless the existing terminal is at least 3 feet (914 mm) above such opening. Whenever necessary, the owner of the new building shall at his or her own expense, and with approval of the adjoining owner, offset the vent stack of the adjacent existing building to a distance of 10 feet (3048 mm ) or more from such openings, or shall extend such vent stack to a height of at least 3 feet (924 mm) above the topmost opening. 903.6 Reserved. 903.7 Reserved. SECTION PC 904 OUTDOOR VENT EXTENSIONS 904 .1 Required vent extension. The vent system serving each building drain shall have not less than one vent pipe that extends to the outdoors. 904. 1.1 Installation. The required vent shall be a dry vent that connects to the building drain or an extension of a drain that connects to the building drain. Such vent shall not be an island fixture vent as allowed by Section 916. 904.1.2 Size. The required vent shall be sized in accordance with Section 906.2 based on the required size of the building drain. 904.2 Vent stack required. A vent stack shall be required for every drainage stack that has three branch intervals or more . 904.3 Vent termination. Vent stacks or stack vents shall terminate outdoors above the roof or to the stack vent portion of the soil or waste stack, at least 6 inches (152 mm) above the flood level of the highest fixture connection discharging into the soil or waste stack. 904.4 Vent connection at base. Vent stacks shall connect to the base of the drainage stack. The vent stack shall co nnect at or below the lowest horizontal branch. Where the vent stack connects to the building drain, the connection shall be located downstream of the drainage stack and within a distance of 10 times the diameter of the drainage stack. 904.5 Vent headers. Stack vents and vent stacks connected into a common vent header at the top of the stacks and extending to the open air above the roof at one point shall be sized in accordance with the requirements of Section 906.1, but shall not be smaller than the smalle st stack vent . The number of fixture units shall be the sum of all fixture units on all stacks connected thereto, and the developed length shall be the longest vent length from the intersection at the base of the most distant stack to the vent terminal in the open air, as a direct extension of one stack. 904.6 Sub - stack connections. Where it is desired to terminate stacks at a point below the roof terminus of the main vent stack, the sub - stack may connect to the main vent stack provided the portion of the m ain vent stack above the connection is sized for the total fixture unit load connected thereto, and for the maximum developed length of the stack or sub - stack. SECTION PC 905 VENT CONNECTIONS AND GRADES 905.1 Connection. Individual , branch and circuit vents shall connect to a vent stack, stack vent, or extend to the open air above the roof . VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 3 905.2 Grade. Vent and branch vent pipes shall be so graded and connected as to drain back to the drainage pipe by gravity. 905.3 Vent connection to drainage system. Every dry vent connecting to a horizontal drain shall connect above the centerline of the horizontal drain pipe. 905.4 Reserved. 905.5 Height above fixtures. A connection between a vent pipe and a vent stack or stack vent shall be made at not less than 6 inches (152 mm) above the flood level rim of the highest fixture served by the vent. Horizontal vent pipes forming branch vents, relief vents or loop vents shall be located not less than 6 inches (152 mm) above the flood level rim of the highest fix ture served. 905.6 Vent for future fixtures. Where the drainage piping has been roughed - in for future fixtures, a rough - in con- nection for a vent shall be installed. The vent size shall be not less than one - half the diameter of the rough - in drain to be serv ed. The vent rough - in shall connect to the vent system, or shall be vented by other means as provided for in this chapter. The connection shall be identified to indicate that it is a vent. SECTION PC 906 VENT PIPE SIZING 906.1 Size of stack vents and vent stacks. The minimum required diameter of stack vents and vent stacks shall be determined from the developed length and the total of drainage fixture units connected thereto in accordance with Table 906.1, but in no case shall the diameter be less than one - half the diameter of the drain served or less than 1 1 / 4 inches (32 mm). TABLE 906.1 SIZE AND DEVELOPED LENGTH OF STACK VENTS AND VENT STACKS DIAMETER OF SOIL OR WASTE STACK (inches) TOTAL FIXTURE UNITS BEING VENTED (dfu) MAXIMUM DEVELOPED LENGTH OF VENT (f eet) a DIAMETER OF VENT (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 5 6 8 10 12 1 1 / 4 2 30 — — — — — — — — — — 1 1 / 2 8 50 150 1 1 / 2 10 30 100 2 12 — 75 200 — — — — — — — — 2 20 30 50 150 — 2 1 / 2 42 26 30 100 300 3 10 — 42 150 360 1,040 — — — — — — 3 21 32 110 270 810 3 53 27 94 230 680 3 102 — 25 86 210 620 — — — — — — 4 43 — 35 85 250 980 4 140 — 27 65 200 750 4 320 — — 23 55 170 640 — — — — — VENTS 9 - 4 2022 NEW YORK CITY PLUMBING CODE 4 540 21 50 150 580 — 5 190 28 82 320 990 5 490 — — — 21 63 250 760 — — — — 5 940 18 53 210 670 5 1,400 16 49 190 590 6 500 — — — — 33 130 400 1,000 — — — 6 1,100 — 26 100 310 780 6 2,000 — 22 84 260 660 6 2,900 — — — — 20 77 240 600 — — — 8 1,800 — 31 95 240 940 8 3,400 — 24 73 190 729 8 5,600 — — — — — 20 62 160 610 — — 8 7,600 18 56 140 560 — 10 4,000 — 31 78 310 960 10 7,200 — — — — — — 24 60 240 740 — 10 11,000 20 51 200 630 10 15,000 18 46 180 571 12 7,300 — — — — — — — 31 120 380 940 12 13,000 — 24 94 300 720 12 20,000 — 20 79 250 610 12 26,000 — — — — — — — 18 72 230 500 15 15,000 — 40 130 310 15 25,000 — 31 96 240 15 38,000 — — — — — — — — 26 81 200 15 50,000 24 74 180 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm. a. The developed length shall be measured from the vent connection to the open air. 906.2 Vents other than stack vents or vent stacks. The diameter of individual vents, branch vents, circuit vents and relief vents shall be at least one - half the required diameter of the drain served. The required size of the drain shall be determined in accordance with Table 710.1(2). Vent pipes shall not be less than 1 1 / 4 inches (32 mm) in diameter. Vents shall be sized in accordance with Table 906.1 utilizing the drainage fixture units and the corresponding VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 5 developed length. Relief vents for soil and waste stacks in buildings having more than 10 branch intervals shall be sized in accordance with Section 908.2. 906.3 Developed length. The developed length of individual, branch, circuit and relief vents shall be measured from the farthest point of vent connection to the drainage system to the point of connection to the vent stack, stack vent or termination outside of the building. 906.4 Multiple branch vents. Where multiple branch vents are connected to a common branch vent, the common branch vent shall be sized in accordance with this section based on the size of the co mmon horizontal drainage branch that is or would be required to serve the total drainage fixture unit load being vented. 906.5 Ejector vents. Ejector vent sizes shall be determined in accordance with Sections 906.5.1 and 906.5.2. 906.5.1 Sewage pumps and s ewage ejectors other than pneumatic. Drainage piping below sewer level shall be vented in the same manner as that of a gravity system. Building sump vent sizes for sumps with sewage pumps or sewage ejectors, other than pneumatic, shall be determined in acc ordance with Table 906.5.1. Where a building sump vent connects to a sanitary vent system, the sanitary branch vent shall be at least 3 inches (76 mm) in diameter. TABLE 906.5.1 SIZE AND LENGTH OF SUMP VENTS DISCHARGE CAPACITY OF PUMP (gpm) MAXIMUM DEVELOP ED LENGTH OF VENT (feet) a Diameter of vent (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 10 No limit b No limit No limit No limit No limit No limit 20 270 No limit No limit No limit No limit No limit 40 72 160 No limit No limit No limit No limit 60 31 75 270 No limit No limit No limit 80 16 41 150 380 No limit No limit 100 10 c 25 97 250 No limit No limit 150 Not permitted 10 c 44 110 370 No limit 200 Not permitted Not permitted 20 60 210 No limit 250 Not permitted Not permitted 10 36 132 No limit 300 Not permitted Not permitted 10 c 22 88 380 400 Not permitted Not permitted Not permitted 10 c 44 210 500 Not permitted Not permitted Not permitted Not permitted 24 130 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 gallon per minute = 3.785 L/m. a. Developed length plus an appropriate allowance for entrance losses and friction due to fittings, changes in direction and dia meter. Suggested allowances shall be obtained from NBS Monograph 31 or other approved sources. An allowance of 50 percent of the de veloped length shall be assumed if a more precise value is not available. b. Actual values greater than 500 feet. c. Less than 10 feet. 906.5.2 Pneumatic sewage ejectors. The air pressure relief pipe from a pneumatic sewage ejector shall be con- nected to a n independent vent stack terminating as required for vent extensions through the roof. The relief pipe VENTS 9 - 6 2022 NEW YORK CITY PLUMBING CODE shall be sized to relieve air pressure inside the ejector to atmospheric pressure, but shall be not less than 1 1 / 2 inches (38 mm) in size. SECTION PC 907 VENTS FOR STACK OFFSETS 907.1 Vent for horizontal offset of drainage stack. Horizontal offsets of drainage stacks shall be vented where five or more branch intervals are located above the offset. The offset shall be vented by venting the upper section of the drainage stack and the lower section of the drainage stack. 907.2 Upper section. The upper section of the drainage stack shall be vented as a separate stack with a vent stack connection installed in accordance with Section 904.4. The offset shall be considered the base of the stack. 907.3 Lower section. The lower section of the drainage stack shall be vented by a yoke vent connecting between the offset and the next lower horizontal branch. The yoke vent connection shall be permitted to be a vertical extension of the drainage stack. The size of the yoke vent and connection shall be a minimum of the size required for the vent stack of the drainage stack. SECTION PC 908 RELIEF VENTS — STACKS OF MORE THAN 10 BRANCH INTERVALS 908.1 Where required. Soil and w aste stacks in buildings having more than 10 branch intervals shall be provided with a relief vent at each tenth interval installed, beginning with the top floor. 908.2 Size and connection. The size of the relief vent shall be equal to the size of the vent stack to which it connects. The lower end of each relief vent shall connect to the soil or waste stack through a wye below the horizontal branch serving the floor, and the upper end shall connect to the vent stack through a tee or inverted wye not less th an 3 feet (914 mm) above the floor. SECTION PC 909 FIXTURE VENTS 909.1 Distance of trap from vent. Each fixture trap shall have a protecting vent located so that the slope and the developed length in the fixture drain from the trap weir to the vent fitting are within the requirements set forth in Table 909.1. Exception: The developed length of the fixture drain from the trap weir to the vent fitting for self - siphoning fix- tures, such as water closets, shall not be limited. TABLE 909.1 MAXIMUM DISTANCE OF FIX TURE TRAP FROM VENT SIZE OF TRAP (inches) SLOPE (inch per foot) DISTANCE FROM TRAP (feet) 1 1 / 4 1 / 4 5 1 1 / 2 1 / 4 6 2 1 / 4 8 3 1 / 8 12 4 1 / 8 16 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 inch per foot = 83.3 mm/m. VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 7 909.2 Venting of fixture drains. The vent for a fixture drain, except where serving a fixture with integral traps, such as water closets, shall connect above the weir of the fixture trap being vented. 909.3 Crown vent. A vent shall not be installed within two pipe diameters of the trap weir . SECTION PC 910 INDIVIDUAL VENT 910.1 Individual vent permitted. Each trap and trapped fixture is permitted to be provided with an individual vent. The individual vent shall connect to the fixture drain of the trap or trapped fixture being vente d in accordance with section 909.1, but at a distance not to exceed 16 feet (4876 mm). 910.2 Floor drain vents. No vents will be required for piping serving floor drains when the floor drain is located not more than 15 feet (4572 mm) from the vented line to which it connects. SECTION PC 911 COMMON VENT 911.1 Individual vent as common vent. An individual vent is permitted to vent two traps or trapped fixtures as a common vent. The traps or trapped fixtures being common vented shall be located on the same floor level. 911.2 Connection at the same level. Where the fixture drains being common vented connect at the same level, the vent connection shall be at the interconnection of the fixture drains. Exception: Where wet vents are permitted by this code, the wet vent connection may be located downstream of the interconnection. 911.3 Connection at different levels. Where the fixture drains connect at different levels, the vent shall connect as a vertical extension of the vertical drain. The vertical drain p ipe connecting the two fixture drains shall be considered the vent for the lower fixture drain, and shall be sized in accordance with Table 911.3 . The upper fixture shall not be a water closet. TABLE 911.3 COMMON VENT SIZES PIPE SIZE (inches) MAXIMUM DISCH ARGE FROM UPPER FIXTURE DRAIN (dfu) 1 1 / 2 1 2 4 2 1 / 2 to 3 6 For SI: 1 inch = 25.4 mm. SECTION PC 912 WET VENTING 912.1 Horizontal wet vent permitted. Any combination of fixtures within one bathroom group located in the same room is permitted to be vented by a horizontal wet vent. The wet vent shall be considered the vent for the fixtures and shall extend from the connection of the dry vent along the direction of the flow in the drain pipe to the most down- stream fixture drain connection to the horizo ntal branch drain. Each wet - vented fixture drain shall connect inde- pendently to the horizontal wet vent. Only the fixtures within the bathroom groups shall connect to the wet - vented horizontal branch drain. Any additional fixtures shall discharge downstrea m of the horizontal wet vent. 912.1.1 Vertical wet vent permitted. Any combination of fixtures within one bathroom group is permitted to be vented by a vertical wet vent. The vertical wet vent shall be considered the vent for the fixtures and shall extend VENTS 9 - 8 2022 NEW YORK CITY PLUMBING CODE from the connection of the dry vent down to the lowest fixture drain connection. Each wet - vented fixture shall connect independently to the vertical wet vent. Fixture drains shall connect above or at the same elevation as the water closet fixture drain. Th e dry - vent connection to the vertical wet vent shall be an individual or common vent serving one or two fixtures. 912.2 Dry - vent connection. The required dry - vent connection for wet - vented systems shall comply with Sections 912.2.1 and 912.2.2. 912.2.1 Hor izontal wet vent. The dry - vent connection for a horizontal wet - vent system shall be an individual vent or a common vent for any bathroom group fixture, except an emergency floor drain. Where the dry - vent connects to a water closet fixture drain, the drain shall connect horizontally to the horizontal wet - vent system. Not more than one wet - vented fixture drain shall discharge upstream of the dry - vented fixture drain connection. 912.2.2 Vertical wet vent. The dry - vent connection for a vertical wet - vent system shall be an individual vent or common vent for the most upstream fixture drain. 912.3 Size. The dry vent serving the wet vent shall be sized based on the largest required diameter of pipe within the wet - vent system served by the dry vent. The wet vent shal l be of a size not less than that specified in Table 912.3, based on the fixture unit discharge to the wet vent. TABLE 912.3 WET VENT SIZE MINIMUM WET VENT PIPE SIZE (inches) MAXIMUM DRAINAGE FIXTURE UNIT LOAD (dfu) 2 4 2 1 / 2 6 3 12 For SI: 1 inch = 25.4 mm. SECTION PC 913 RESERVED SECTION PC 914 CIRCUIT VENTING 914.1 Circuit vent permitted. A maximum of eight fixtures connected to a horizontal branch drain shall be permitted to be circuit vented. Each fixture drain shall connect horizontally to the h orizontal branch being circuit vented. The horizontal branch drain shall be classified as a vent from the most downstream fixture drain connection to the most upstream fixture drain connection to the horizontal branch. 914.1.1 Multiple circuit - vented branc hes. Circuit - vented horizontal branch drains are permitted to be connected together. Each group of a maximum of eight fixtures shall be considered a separate circuit vent and shall conform to the requirements of this section. 914.2 Vent connection. The cir cuit vent connection shall be located between the two most upstream fixture drains. The vent shall connect to the horizontal branch and shall be installed in accordance with Section 905. The circuit vent pipe shall not receive the discharge of any soil or waste. 914.3 Slope and size of horizontal branch. The slope of the vent section of the horizontal branch drain shall be not greater than one unit vertical in 12 units horizontal (8.3 - percent slope). The entire length of the vent section of the horizontal branch drain shall be sized for the total drainage discharge to the branch. VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 9 914.3.1 Size of multiple circuit vent. Each separate circuit - vented horizontal branch that is interconnected shall be sized independently in accordance with Section 914.3 . The dow nstream circuit - vented horizontal branch shall be sized for the total discharge into the branch, including the upstream branches and the fixtures within the branch. 914.4 Relief vent. A relief vent shall be provided for circuit - vented horizontal branches r eceiving the discharge of four or more water closets and connecting to a drainage stack that receives the discharge of soil or waste from upper horizontal branches. 914.4.1 Connection and installation. The relief vent shall connect to the horizontal branch drain between the stack and the most downstream fixture drain of the circuit vent. The relief vent shall be installed in accordance with Section 905. 914.4.2 Fixture drain or branch. The relief vent is permitted to be a fixture drain or fixture branch for fixtures located within the same branch interval as the circuit - vented horizontal branch. The maximum discharge to a relief vent shall be four fixture units. 914.5 Additional fixtures. Fixtures, other than the circuit - vented fixtures, are permitted to dis charge to the horizontal branch drain. Such fixtures shall be located on the same floor as the circuit - vented fixtures and shall be either individ- ually or common vented. SECTION PC 915 COMBINATION WASTE AND VENT SYSTEM 915.1 Types of fixtures. A combination waste and vent system shall not serve fixtures other than floor drains, lava- tories and drinking fountains. Combination waste and vent systems shall not receive the discharge from a food waste disposer or clinical sink. 915.2 Installation. The c ombination waste and vent system shall be a horizontal piping system. The only vertical pipe of a combination waste and vent system shall be the connection between the fixture drain and the horizontal combi- nation waste and vent pipe. The vertical distance shall not exceed 8 feet (2438 mm). 915.2.1 Slope. The slope at a horizontal combination waste and vent pipe shall not exceed one - half unit vertical in 12 units horizontal (4 - percent slope) and shall not be less than indicated in Table 704.1. 915.2.2 Size a nd length. The size of a combination waste and vent pipe shall be not less than that indicated in Table 915.2.2. The horizontal length of a combination waste and vent system shall be unlimited. TABLE 915.2.2 SIZE OF COMBINATION WASTE AND VENT PIPE DIAMETER PIPE (inches) MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS (dfu) Connecting to a horizontal branch or stack Connecting to a building drain or building subdrain 2 3 4 2 1 / 2 6 26 3 12 31 4 20 50 5 160 250 6 360 575 For SI: 1 inch = 25.4 mm. VENTS 9 - 10 2022 NEW YORK CITY PLUMBING CODE 915.2.3 Connection. The combination waste and vent system shall be provided with a dry vent connected at any point within the system or the system shall connect to a horizontal drain that serves vented fixtures located on the same floor . Combination waste and vent systems connecting to building drains receiving only the discharge from one or more stacks shall be provided with a dry vent. The vent connection to the combination waste and vent pipe shall extend vertically to a point not less than 6 inches (152 mm) above the flood level rim of the highest fixture being vented before offsetting horizontally. 915.2.4 Vent size. The vent shall be sized for the total drainage fixture unit load in accordance with Section 906.2 . 915.2.5 Fixture branch or drain. The fi xture branch or fixture drain shall connect to the combination waste and vent within a distance specified in Table 909.1. The combination waste and vent pipe shall be considered the vent for the fixture . SECTION PC 916 ISLAND FIXTURE VENTING 916.1 Limitati on. Island fixture venting shall not be permitted for fixtures other than sinks and lavatories. Residential kitchen sinks with a dishwasher waste connection, a food waste disposer , or both, in combination with the kitchen sink waste, shall be permitted to be vented in accordance with this section. 916.2 Vent connection. The island fixture vent shall connect to the fixture drain as required for an individual or common vent. The vent shall rise vertically to above the drainage outlet of the fixture being vent ed before offsetting horizontally or vertically downward. The vent or branch vent for multiple island fixture vents shall extend to a point not less than 6 inches (152 mm) above the highest island fixture being vented before connecting to the outside vent terminal. 916.3 Vent installation below the fixture flood level rim. The vent located below the flood level rim of the fixture being vented shall be installed as required for drainage piping in accordance with Chapter 7, except for sizing. The vent shall b e sized in accordance with Section 906.2 . The lowest point of the island fixture vent shall connect full size to the drainage system. The connection shall be to a vertical drain pipe or to the top half of a horizontal drain pipe. Cleanouts shall be provided in the island fixture vent to permit rodding of all vent piping located below the flood level rim of the fixtures. Rodding in both directions shall be permitted through a cleanout. SECTION PC 917 RESERVED SECTION PC 918 RESERVED SECTION PC 919 ENG INEERED VENT SYSTEMS 919.1 General. Engineered vent systems shall comply with this section and Section 28 - 113.2.2 of the Administrative Code . 919.2 Individual branch fixture and individual fixture header vents. The maximum developed length of individual fi xture vents to vent branches and vent headers shall be determined in accordance with Table 919.2 for the minimum pipe diameters at the indicated vent airflow rates. The individual vent airflow rate shall be determined in accordance with the following: Q h,b = N n,b Q ν (Equation 9 - 1) For SI: Q h , b = N n , b Q ν (0.4719 L/s) where: VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 11 N n , b = Number of fixtures per header (or vent branch) ÷ total number of fixtures connected to vent stack. Q h , b = Vent branch or vent header airflow rate (cfm). Q ν = Total vent stack airflow rate (cfm). Q ν (gpm) = 27.8 r s 2/3 (1 – rs ) D 8/3 Q ν (cfm) = 0.134 Q ν (gpm) where: D = Drainage stack diameter (inches). Q w = Design discharge load (gpm). r s = Waste water flow area to total area. = Q w / 27.8 D 8/3 Individual vent airflow rates are obtained by equally distributing Q h,b into one - half the total number of fixtures on the branch or header for more than two fixtures; for an odd number of total fixtures, decrease by one; for one fixture, apply the full value of Q h, b . Individual vent developed length shall be increased by 20 percent of the distance from the vent stack to the fixture vent connecti on on the vent branch or header. TABLE 919.2 MINIMUM DIAMETER AND MAXIMUM LENGTH OF INDIVIDUAL BRANCH FIXTURE VENTS AND INDIVIDUAL FIXTURE HEADER VENTS FOR SMOOTH PIPES DIAMETER OF VENT PIPE (inches) INDIVIDUAL VENT AIRFLOW RATE (cubic feet per minute) Maximum developed length of vent (feet) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 1 / 2 95 25 13 8 5 4 3 2 1 1 1 1 1 1 1 1 1 1 1 1 3 / 4 100 88 47 30 20 15 10 9 7 6 5 4 3 3 3 2 2 2 2 1 1 — — 100 94 65 48 37 29 24 20 17 14 12 11 9 8 7 7 6 6 1 1 / 4 — — — — — — — 100 87 73 62 53 46 40 36 32 29 26 23 21 1 1 / 2 — — — — — — — — — — — 100 96 84 75 65 60 54 49 45 2 — — — — — — — — — — — — — — — — — — — 100 For SI: 1 inch = 25.4 mm, 1 cubic foot per minute = 0.4719 L/s, 1 foot = 304.8 mm. 919.3 A licensed professional engineer shall certify design. An engineer shall also inspect and certify the system upon completion of the system. SECTION PC 920 COMPUTERIZED VENT DESIGN 920.1 Design of vent system. The sizing, design and layout of the vent system shall be permitted to be determined by computer program design methods which shall be approved by the commissioner to insure compliance with the minimum standards of this code . 920.2 System capacity. The vent system shall be based on the air capacit y requirements of the drainage system under a peak load condition. VENTS 9 - 12 2022 NEW YORK CITY PLUMBING CODE 920.3 Design shall be certified by a licensed professional engineer. An engineer shall also inspect and certify the system upon completion of the system.03.5.1 New vent terminals. An open vent terminal from a drainage system of the new or altered building shall not be located directly beneath any door, o perable window, or other air intake opening of the building or of an adjacent building, and any such vent terminal shall not be within 10 feet (3048 mm) horizontally of such an opening unless it is at least 3 feet (914 mm) above the top of such opening. Wh en the consent of the owner of an adjoining taller build - ing is obtained, the owner of the new or altered building shall be permitted to carry the new vent stack, with adequate support, to a level above the higher existing roof. 903.5.2 New openings. A doo r, operable window, or other air intake opening of the new or altered building shall not be located within 10 feet (3048 mm) horizontally from an open vent terminal from a drainage system of an existing adjacent building unless the existing terminal is at least 3 feet (914 mm) above such opening. Whenever necessary, the owner of the new building shall at his or her own expense, and with approval of the adjoining owner, offset the vent stack of the adjacent existing building to a distance of 10 feet (3048 mm ) or more from such openings, or shall extend such vent stack to a height of at least 3 feet (924 mm) above the topmost opening. 903.6 Reserved. 903.7 Reserved. SECTION PC 904 OUTDOOR VENT EXTENSIONS 904 .1 Required vent extension. The vent system serving each building drain shall have not less than one vent pipe that extends to the outdoors. 904. 1.1 Installation. The required vent shall be a dry vent that connects to the building drain or an extension of a drain that connects to the building drain. Such vent shall not be an island fixture vent as allowed by Section 916. 904.1.2 Size. The required vent shall be sized in accordance with Section 906.2 based on the required size of the building drain. 904.2 Vent stack required. A vent stack shall be required for every drainage stack that has three branch intervals or more . 904.3 Vent termination. Vent stacks or stack vents shall terminate outdoors above the roof or to the stack vent portion of the soil or waste stack, at least 6 inches (152 mm) above the flood level of the highest fixture connection discharging into the soil or waste stack. 904.4 Vent connection at base. Vent stacks shall connect to the base of the drainage stack. The vent stack shall co nnect at or below the lowest horizontal branch. Where the vent stack connects to the building drain, the connection shall be located downstream of the drainage stack and within a distance of 10 times the diameter of the drainage stack. 904.5 Vent headers. Stack vents and vent stacks connected into a common vent header at the top of the stacks and extending to the open air above the roof at one point shall be sized in accordance with the requirements of Section 906.1, but shall not be smaller than the smalle st stack vent . The number of fixture units shall be the sum of all fixture units on all stacks connected thereto, and the developed length shall be the longest vent length from the intersection at the base of the most distant stack to the vent terminal in the open air, as a direct extension of one stack. 904.6 Sub - stack connections. Where it is desired to terminate stacks at a point below the roof terminus of the main vent stack, the sub - stack may connect to the main vent stack provided the portion of the m ain vent stack above the connection is sized for the total fixture unit load connected thereto, and for the maximum developed length of the stack or sub - stack. SECTION PC 905 VENT CONNECTIONS AND GRADES 905.1 Connection. Individual , branch and circuit vents shall connect to a vent stack, stack vent, or extend to the open air above the roof . VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 3 905.2 Grade. Vent and branch vent pipes shall be so graded and connected as to drain back to the drainage pipe by gravity. 905.3 Vent connection to drainage system. Every dry vent connecting to a horizontal drain shall connect above the centerline of the horizontal drain pipe. 905.4 Reserved. 905.5 Height above fixtures. A connection between a vent pipe and a vent stack or stack vent shall be made at not less than 6 inches (152 mm) above the flood level rim of the highest fixture served by the vent. Horizontal vent pipes forming branch vents, relief vents or loop vents shall be located not less than 6 inches (152 mm) above the flood level rim of the highest fix ture served. 905.6 Vent for future fixtures. Where the drainage piping has been roughed - in for future fixtures, a rough - in con- nection for a vent shall be installed. The vent size shall be not less than one - half the diameter of the rough - in drain to be serv ed. The vent rough - in shall connect to the vent system, or shall be vented by other means as provided for in this chapter. The connection shall be identified to indicate that it is a vent. SECTION PC 906 VENT PIPE SIZING 906.1 Size of stack vents and vent stacks. The minimum required diameter of stack vents and vent stacks shall be determined from the developed length and the total of drainage fixture units connected thereto in accordance with Table 906.1, but in no case shall the diameter be less than one - half the diameter of the drain served or less than 1 1 / 4 inches (32 mm). TABLE 906.1 SIZE AND DEVELOPED LENGTH OF STACK VENTS AND VENT STACKS DIAMETER OF SOIL OR WASTE STACK (inches) TOTAL FIXTURE UNITS BEING VENTED (dfu) MAXIMUM DEVELOPED LENGTH OF VENT (f eet) a DIAMETER OF VENT (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 5 6 8 10 12 1 1 / 4 2 30 — — — — — — — — — — 1 1 / 2 8 50 150 1 1 / 2 10 30 100 2 12 — 75 200 — — — — — — — — 2 20 30 50 150 — 2 1 / 2 42 26 30 100 300 3 10 — 42 150 360 1,040 — — — — — — 3 21 32 110 270 810 3 53 27 94 230 680 3 102 — 25 86 210 620 — — — — — — 4 43 — 35 85 250 980 4 140 — 27 65 200 750 4 320 — — 23 55 170 640 — — — — — VENTS 9 - 4 2022 NEW YORK CITY PLUMBING CODE 4 540 21 50 150 580 — 5 190 28 82 320 990 5 490 — — — 21 63 250 760 — — — — 5 940 18 53 210 670 5 1,400 16 49 190 590 6 500 — — — — 33 130 400 1,000 — — — 6 1,100 — 26 100 310 780 6 2,000 — 22 84 260 660 6 2,900 — — — — 20 77 240 600 — — — 8 1,800 — 31 95 240 940 8 3,400 — 24 73 190 729 8 5,600 — — — — — 20 62 160 610 — — 8 7,600 18 56 140 560 — 10 4,000 — 31 78 310 960 10 7,200 — — — — — — 24 60 240 740 — 10 11,000 20 51 200 630 10 15,000 18 46 180 571 12 7,300 — — — — — — — 31 120 380 940 12 13,000 — 24 94 300 720 12 20,000 — 20 79 250 610 12 26,000 — — — — — — — 18 72 230 500 15 15,000 — 40 130 310 15 25,000 — 31 96 240 15 38,000 — — — — — — — — 26 81 200 15 50,000 24 74 180 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm. a. The developed length shall be measured from the vent connection to the open air. 906.2 Vents other than stack vents or vent stacks. The diameter of individual vents, branch vents, circuit vents and relief vents shall be at least one - half the required diameter of the drain served. The required size of the drain shall be determined in accordance with Table 710.1(2). Vent pipes shall not be less than 1 1 / 4 inches (32 mm) in diameter. Vents shall be sized in accordance with Table 906.1 utilizing the drainage fixture units and the corresponding VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 5 developed length. Relief vents for soil and waste stacks in buildings having more than 10 branch intervals shall be sized in accordance with Section 908.2. 906.3 Developed length. The developed length of individual, branch, circuit and relief vents shall be measured from the farthest point of vent connection to the drainage system to the point of connection to the vent stack, stack vent or termination outside of the building. 906.4 Multiple branch vents. Where multiple branch vents are connected to a common branch vent, the common branch vent shall be sized in accordance with this section based on the size of the co mmon horizontal drainage branch that is or would be required to serve the total drainage fixture unit load being vented. 906.5 Ejector vents. Ejector vent sizes shall be determined in accordance with Sections 906.5.1 and 906.5.2. 906.5.1 Sewage pumps and s ewage ejectors other than pneumatic. Drainage piping below sewer level shall be vented in the same manner as that of a gravity system. Building sump vent sizes for sumps with sewage pumps or sewage ejectors, other than pneumatic, shall be determined in acc ordance with Table 906.5.1. Where a building sump vent connects to a sanitary vent system, the sanitary branch vent shall be at least 3 inches (76 mm) in diameter. TABLE 906.5.1 SIZE AND LENGTH OF SUMP VENTS DISCHARGE CAPACITY OF PUMP (gpm) MAXIMUM DEVELOP ED LENGTH OF VENT (feet) a Diameter of vent (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 10 No limit b No limit No limit No limit No limit No limit 20 270 No limit No limit No limit No limit No limit 40 72 160 No limit No limit No limit No limit 60 31 75 270 No limit No limit No limit 80 16 41 150 380 No limit No limit 100 10 c 25 97 250 No limit No limit 150 Not permitted 10 c 44 110 370 No limit 200 Not permitted Not permitted 20 60 210 No limit 250 Not permitted Not permitted 10 36 132 No limit 300 Not permitted Not permitted 10 c 22 88 380 400 Not permitted Not permitted Not permitted 10 c 44 210 500 Not permitted Not permitted Not permitted Not permitted 24 130 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 gallon per minute = 3.785 L/m. a. Developed length plus an appropriate allowance for entrance losses and friction due to fittings, changes in direction and dia meter. Suggested allowances shall be obtained from NBS Monograph 31 or other approved sources. An allowance of 50 percent of the de veloped length shall be assumed if a more precise value is not available. b. Actual values greater than 500 feet. c. Less than 10 feet. 906.5.2 Pneumatic sewage ejectors. The air pressure relief pipe from a pneumatic sewage ejector shall be con- nected to a n independent vent stack terminating as required for vent extensions through the roof. The relief pipe VENTS 9 - 6 2022 NEW YORK CITY PLUMBING CODE shall be sized to relieve air pressure inside the ejector to atmospheric pressure, but shall be not less than 1 1 / 2 inches (38 mm) in size. SECTION PC 907 VENTS FOR STACK OFFSETS 907.1 Vent for horizontal offset of drainage stack. Horizontal offsets of drainage stacks shall be vented where five or more branch intervals are located above the offset. The offset shall be vented by venting the upper section of the drainage stack and the lower section of the drainage stack. 907.2 Upper section. The upper section of the drainage stack shall be vented as a separate stack with a vent stack connection installed in accordance with Section 904.4. The offset shall be considered the base of the stack. 907.3 Lower section. The lower section of the drainage stack shall be vented by a yoke vent connecting between the offset and the next lower horizontal branch. The yoke vent connection shall be permitted to be a vertical extension of the drainage stack. The size of the yoke vent and connection shall be a minimum of the size required for the vent stack of the drainage stack. SECTION PC 908 RELIEF VENTS — STACKS OF MORE THAN 10 BRANCH INTERVALS 908.1 Where required. Soil and w aste stacks in buildings having more than 10 branch intervals shall be provided with a relief vent at each tenth interval installed, beginning with the top floor. 908.2 Size and connection. The size of the relief vent shall be equal to the size of the vent stack to which it connects. The lower end of each relief vent shall connect to the soil or waste stack through a wye below the horizontal branch serving the floor, and the upper end shall connect to the vent stack through a tee or inverted wye not less th an 3 feet (914 mm) above the floor. SECTION PC 909 FIXTURE VENTS 909.1 Distance of trap from vent. Each fixture trap shall have a protecting vent located so that the slope and the developed length in the fixture drain from the trap weir to the vent fitting are within the requirements set forth in Table 909.1. Exception: The developed length of the fixture drain from the trap weir to the vent fitting for self - siphoning fix- tures, such as water closets, shall not be limited. TABLE 909.1 MAXIMUM DISTANCE OF FIX TURE TRAP FROM VENT SIZE OF TRAP (inches) SLOPE (inch per foot) DISTANCE FROM TRAP (feet) 1 1 / 4 1 / 4 5 1 1 / 2 1 / 4 6 2 1 / 4 8 3 1 / 8 12 4 1 / 8 16 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 inch per foot = 83.3 mm/m. VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 7 909.2 Venting of fixture drains. The vent for a fixture drain, except where serving a fixture with integral traps, such as water closets, shall connect above the weir of the fixture trap being vented. 909.3 Crown vent. A vent shall not be installed within two pipe diameters of the trap weir . SECTION PC 910 INDIVIDUAL VENT 910.1 Individual vent permitted. Each trap and trapped fixture is permitted to be provided with an individual vent. The individual vent shall connect to the fixture drain of the trap or trapped fixture being vente d in accordance with section 909.1, but at a distance not to exceed 16 feet (4876 mm). 910.2 Floor drain vents. No vents will be required for piping serving floor drains when the floor drain is located not more than 15 feet (4572 mm) from the vented line to which it connects. SECTION PC 911 COMMON VENT 911.1 Individual vent as common vent. An individual vent is permitted to vent two traps or trapped fixtures as a common vent. The traps or trapped fixtures being common vented shall be located on the same floor level. 911.2 Connection at the same level. Where the fixture drains being common vented connect at the same level, the vent connection shall be at the interconnection of the fixture drains. Exception: Where wet vents are permitted by this code, the wet vent connection may be located downstream of the interconnection. 911.3 Connection at different levels. Where the fixture drains connect at different levels, the vent shall connect as a vertical extension of the vertical drain. The vertical drain p ipe connecting the two fixture drains shall be considered the vent for the lower fixture drain, and shall be sized in accordance with Table 911.3 . The upper fixture shall not be a water closet. TABLE 911.3 COMMON VENT SIZES PIPE SIZE (inches) MAXIMUM DISCH ARGE FROM UPPER FIXTURE DRAIN (dfu) 1 1 / 2 1 2 4 2 1 / 2 to 3 6 For SI: 1 inch = 25.4 mm. SECTION PC 912 WET VENTING 912.1 Horizontal wet vent permitted. Any combination of fixtures within one bathroom group located in the same room is permitted to be vented by a horizontal wet vent. The wet vent shall be considered the vent for the fixtures and shall extend from the connection of the dry vent along the direction of the flow in the drain pipe to the most down- stream fixture drain connection to the horizo ntal branch drain. Each wet - vented fixture drain shall connect inde- pendently to the horizontal wet vent. Only the fixtures within the bathroom groups shall connect to the wet - vented horizontal branch drain. Any additional fixtures shall discharge downstrea m of the horizontal wet vent. 912.1.1 Vertical wet vent permitted. Any combination of fixtures within one bathroom group is permitted to be vented by a vertical wet vent. The vertical wet vent shall be considered the vent for the fixtures and shall extend VENTS 9 - 8 2022 NEW YORK CITY PLUMBING CODE from the connection of the dry vent down to the lowest fixture drain connection. Each wet - vented fixture shall connect independently to the vertical wet vent. Fixture drains shall connect above or at the same elevation as the water closet fixture drain. Th e dry - vent connection to the vertical wet vent shall be an individual or common vent serving one or two fixtures. 912.2 Dry - vent connection. The required dry - vent connection for wet - vented systems shall comply with Sections 912.2.1 and 912.2.2. 912.2.1 Hor izontal wet vent. The dry - vent connection for a horizontal wet - vent system shall be an individual vent or a common vent for any bathroom group fixture, except an emergency floor drain. Where the dry - vent connects to a water closet fixture drain, the drain shall connect horizontally to the horizontal wet - vent system. Not more than one wet - vented fixture drain shall discharge upstream of the dry - vented fixture drain connection. 912.2.2 Vertical wet vent. The dry - vent connection for a vertical wet - vent system shall be an individual vent or common vent for the most upstream fixture drain. 912.3 Size. The dry vent serving the wet vent shall be sized based on the largest required diameter of pipe within the wet - vent system served by the dry vent. The wet vent shal l be of a size not less than that specified in Table 912.3, based on the fixture unit discharge to the wet vent. TABLE 912.3 WET VENT SIZE MINIMUM WET VENT PIPE SIZE (inches) MAXIMUM DRAINAGE FIXTURE UNIT LOAD (dfu) 2 4 2 1 / 2 6 3 12 For SI: 1 inch = 25.4 mm. SECTION PC 913 RESERVED SECTION PC 914 CIRCUIT VENTING 914.1 Circuit vent permitted. A maximum of eight fixtures connected to a horizontal branch drain shall be permitted to be circuit vented. Each fixture drain shall connect horizontally to the h orizontal branch being circuit vented. The horizontal branch drain shall be classified as a vent from the most downstream fixture drain connection to the most upstream fixture drain connection to the horizontal branch. 914.1.1 Multiple circuit - vented branc hes. Circuit - vented horizontal branch drains are permitted to be connected together. Each group of a maximum of eight fixtures shall be considered a separate circuit vent and shall conform to the requirements of this section. 914.2 Vent connection. The cir cuit vent connection shall be located between the two most upstream fixture drains. The vent shall connect to the horizontal branch and shall be installed in accordance with Section 905. The circuit vent pipe shall not receive the discharge of any soil or waste. 914.3 Slope and size of horizontal branch. The slope of the vent section of the horizontal branch drain shall be not greater than one unit vertical in 12 units horizontal (8.3 - percent slope). The entire length of the vent section of the horizontal branch drain shall be sized for the total drainage discharge to the branch. VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 9 914.3.1 Size of multiple circuit vent. Each separate circuit - vented horizontal branch that is interconnected shall be sized independently in accordance with Section 914.3 . The dow nstream circuit - vented horizontal branch shall be sized for the total discharge into the branch, including the upstream branches and the fixtures within the branch. 914.4 Relief vent. A relief vent shall be provided for circuit - vented horizontal branches r eceiving the discharge of four or more water closets and connecting to a drainage stack that receives the discharge of soil or waste from upper horizontal branches. 914.4.1 Connection and installation. The relief vent shall connect to the horizontal branch drain between the stack and the most downstream fixture drain of the circuit vent. The relief vent shall be installed in accordance with Section 905. 914.4.2 Fixture drain or branch. The relief vent is permitted to be a fixture drain or fixture branch for fixtures located within the same branch interval as the circuit - vented horizontal branch. The maximum discharge to a relief vent shall be four fixture units. 914.5 Additional fixtures. Fixtures, other than the circuit - vented fixtures, are permitted to dis charge to the horizontal branch drain. Such fixtures shall be located on the same floor as the circuit - vented fixtures and shall be either individ- ually or common vented. SECTION PC 915 COMBINATION WASTE AND VENT SYSTEM 915.1 Types of fixtures. A combination waste and vent system shall not serve fixtures other than floor drains, lava- tories and drinking fountains. Combination waste and vent systems shall not receive the discharge from a food waste disposer or clinical sink. 915.2 Installation. The c ombination waste and vent system shall be a horizontal piping system. The only vertical pipe of a combination waste and vent system shall be the connection between the fixture drain and the horizontal combi- nation waste and vent pipe. The vertical distance shall not exceed 8 feet (2438 mm). 915.2.1 Slope. The slope at a horizontal combination waste and vent pipe shall not exceed one - half unit vertical in 12 units horizontal (4 - percent slope) and shall not be less than indicated in Table 704.1. 915.2.2 Size a nd length. The size of a combination waste and vent pipe shall be not less than that indicated in Table 915.2.2. The horizontal length of a combination waste and vent system shall be unlimited. TABLE 915.2.2 SIZE OF COMBINATION WASTE AND VENT PIPE DIAMETER PIPE (inches) MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS (dfu) Connecting to a horizontal branch or stack Connecting to a building drain or building subdrain 2 3 4 2 1 / 2 6 26 3 12 31 4 20 50 5 160 250 6 360 575 For SI: 1 inch = 25.4 mm. VENTS 9 - 10 2022 NEW YORK CITY PLUMBING CODE 915.2.3 Connection. The combination waste and vent system shall be provided with a dry vent connected at any point within the system or the system shall connect to a horizontal drain that serves vented fixtures located on the same floor . Combination waste and vent systems connecting to building drains receiving only the discharge from one or more stacks shall be provided with a dry vent. The vent connection to the combination waste and vent pipe shall extend vertically to a point not less than 6 inches (152 mm) above the flood level rim of the highest fixture being vented before offsetting horizontally. 915.2.4 Vent size. The vent shall be sized for the total drainage fixture unit load in accordance with Section 906.2 . 915.2.5 Fixture branch or drain. The fi xture branch or fixture drain shall connect to the combination waste and vent within a distance specified in Table 909.1. The combination waste and vent pipe shall be considered the vent for the fixture . SECTION PC 916 ISLAND FIXTURE VENTING 916.1 Limitati on. Island fixture venting shall not be permitted for fixtures other than sinks and lavatories. Residential kitchen sinks with a dishwasher waste connection, a food waste disposer , or both, in combination with the kitchen sink waste, shall be permitted to be vented in accordance with this section. 916.2 Vent connection. The island fixture vent shall connect to the fixture drain as required for an individual or common vent. The vent shall rise vertically to above the drainage outlet of the fixture being vent ed before offsetting horizontally or vertically downward. The vent or branch vent for multiple island fixture vents shall extend to a point not less than 6 inches (152 mm) above the highest island fixture being vented before connecting to the outside vent terminal. 916.3 Vent installation below the fixture flood level rim. The vent located below the flood level rim of the fixture being vented shall be installed as required for drainage piping in accordance with Chapter 7, except for sizing. The vent shall b e sized in accordance with Section 906.2 . The lowest point of the island fixture vent shall connect full size to the drainage system. The connection shall be to a vertical drain pipe or to the top half of a horizontal drain pipe. Cleanouts shall be provided in the island fixture vent to permit rodding of all vent piping located below the flood level rim of the fixtures. Rodding in both directions shall be permitted through a cleanout. SECTION PC 917 RESERVED SECTION PC 918 RESERVED SECTION PC 919 ENG INEERED VENT SYSTEMS 919.1 General. Engineered vent systems shall comply with this section and Section 28 - 113.2.2 of the Administrative Code . 919.2 Individual branch fixture and individual fixture header vents. The maximum developed length of individual fi xture vents to vent branches and vent headers shall be determined in accordance with Table 919.2 for the minimum pipe diameters at the indicated vent airflow rates. The individual vent airflow rate shall be determined in accordance with the following: Q h,b = N n,b Q ν (Equation 9 - 1) For SI: Q h , b = N n , b Q ν (0.4719 L/s) where: VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 11 N n , b = Number of fixtures per header (or vent branch) ÷ total number of fixtures connected to vent stack. Q h , b = Vent branch or vent header airflow rate (cfm). Q ν = Total vent stack airflow rate (cfm). Q ν (gpm) = 27.8 r s 2/3 (1 – rs ) D 8/3 Q ν (cfm) = 0.134 Q ν (gpm) where: D = Drainage stack diameter (inches). Q w = Design discharge load (gpm). r s = Waste water flow area to total area. = Q w / 27.8 D 8/3 Individual vent airflow rates are obtained by equally distributing Q h,b into one - half the total number of fixtures on the branch or header for more than two fixtures; for an odd number of total fixtures, decrease by one; for one fixture, apply the full value of Q h, b . Individual vent developed length shall be increased by 20 percent of the distance from the vent stack to the fixture vent connecti on on the vent branch or header. TABLE 919.2 MINIMUM DIAMETER AND MAXIMUM LENGTH OF INDIVIDUAL BRANCH FIXTURE VENTS AND INDIVIDUAL FIXTURE HEADER VENTS FOR SMOOTH PIPES DIAMETER OF VENT PIPE (inches) INDIVIDUAL VENT AIRFLOW RATE (cubic feet per minute) Maximum developed length of vent (feet) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 1 / 2 95 25 13 8 5 4 3 2 1 1 1 1 1 1 1 1 1 1 1 1 3 / 4 100 88 47 30 20 15 10 9 7 6 5 4 3 3 3 2 2 2 2 1 1 — — 100 94 65 48 37 29 24 20 17 14 12 11 9 8 7 7 6 6 1 1 / 4 — — — — — — — 100 87 73 62 53 46 40 36 32 29 26 23 21 1 1 / 2 — — — — — — — — — — — 100 96 84 75 65 60 54 49 45 2 — — — — — — — — — — — — — — — — — — — 100 For SI: 1 inch = 25.4 mm, 1 cubic foot per minute = 0.4719 L/s, 1 foot = 304.8 mm. 919.3 A licensed professional engineer shall certify design. An engineer shall also inspect and certify the system upon completion of the system. SECTION PC 920 COMPUTERIZED VENT DESIGN 920.1 Design of vent system. The sizing, design and layout of the vent system shall be permitted to be determined by computer program design methods which shall be approved by the commissioner to insure compliance with the minimum standards of this code . 920.2 System capacity. The vent system shall be based on the air capacit y requirements of the drainage system under a peak load condition. VENTS 9 - 12 2022 NEW YORK CITY PLUMBING CODE 920.3 Design shall be certified by a licensed professional engineer. An engineer shall also inspect and certify the system upon completion of the system.03.5.1 New vent terminals. An open vent terminal from a drainage system of the new or altered building shall not be located directly beneath any door, o perable window, or other air intake opening of the building or of an adjacent building, and any such vent terminal shall not be within 10 feet (3048 mm) horizontally of such an opening unless it is at least 3 feet (914 mm) above the top of such opening. Wh en the consent of the owner of an adjoining taller build - ing is obtained, the owner of the new or altered building shall be permitted to carry the new vent stack, with adequate support, to a level above the higher existing roof. 903.5.2 New openings. A doo r, operable window, or other air intake opening of the new or altered building shall not be located within 10 feet (3048 mm) horizontally from an open vent terminal from a drainage system of an existing adjacent building unless the existing terminal is at least 3 feet (914 mm) above such opening. Whenever necessary, the owner of the new building shall at his or her own expense, and with approval of the adjoining owner, offset the vent stack of the adjacent existing building to a distance of 10 feet (3048 mm ) or more from such openings, or shall extend such vent stack to a height of at least 3 feet (924 mm) above the topmost opening. 903.6 Reserved. 903.7 Reserved. SECTION PC 904 OUTDOOR VENT EXTENSIONS 904 .1 Required vent extension. The vent system serving each building drain shall have not less than one vent pipe that extends to the outdoors. 904. 1.1 Installation. The required vent shall be a dry vent that connects to the building drain or an extension of a drain that connects to the building drain. Such vent shall not be an island fixture vent as allowed by Section 916. 904.1.2 Size. The required vent shall be sized in accordance with Section 906.2 based on the required size of the building drain. 904.2 Vent stack required. A vent stack shall be required for every drainage stack that has three branch intervals or more . 904.3 Vent termination. Vent stacks or stack vents shall terminate outdoors above the roof or to the stack vent portion of the soil or waste stack, at least 6 inches (152 mm) above the flood level of the highest fixture connection discharging into the soil or waste stack. 904.4 Vent connection at base. Vent stacks shall connect to the base of the drainage stack. The vent stack shall co nnect at or below the lowest horizontal branch. Where the vent stack connects to the building drain, the connection shall be located downstream of the drainage stack and within a distance of 10 times the diameter of the drainage stack. 904.5 Vent headers. Stack vents and vent stacks connected into a common vent header at the top of the stacks and extending to the open air above the roof at one point shall be sized in accordance with the requirements of Section 906.1, but shall not be smaller than the smalle st stack vent . The number of fixture units shall be the sum of all fixture units on all stacks connected thereto, and the developed length shall be the longest vent length from the intersection at the base of the most distant stack to the vent terminal in the open air, as a direct extension of one stack. 904.6 Sub - stack connections. Where it is desired to terminate stacks at a point below the roof terminus of the main vent stack, the sub - stack may connect to the main vent stack provided the portion of the m ain vent stack above the connection is sized for the total fixture unit load connected thereto, and for the maximum developed length of the stack or sub - stack. SECTION PC 905 VENT CONNECTIONS AND GRADES 905.1 Connection. Individual , branch and circuit vents shall connect to a vent stack, stack vent, or extend to the open air above the roof . VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 3 905.2 Grade. Vent and branch vent pipes shall be so graded and connected as to drain back to the drainage pipe by gravity. 905.3 Vent connection to drainage system. Every dry vent connecting to a horizontal drain shall connect above the centerline of the horizontal drain pipe. 905.4 Reserved. 905.5 Height above fixtures. A connection between a vent pipe and a vent stack or stack vent shall be made at not less than 6 inches (152 mm) above the flood level rim of the highest fixture served by the vent. Horizontal vent pipes forming branch vents, relief vents or loop vents shall be located not less than 6 inches (152 mm) above the flood level rim of the highest fix ture served. 905.6 Vent for future fixtures. Where the drainage piping has been roughed - in for future fixtures, a rough - in con- nection for a vent shall be installed. The vent size shall be not less than one - half the diameter of the rough - in drain to be serv ed. The vent rough - in shall connect to the vent system, or shall be vented by other means as provided for in this chapter. The connection shall be identified to indicate that it is a vent. SECTION PC 906 VENT PIPE SIZING 906.1 Size of stack vents and vent stacks. The minimum required diameter of stack vents and vent stacks shall be determined from the developed length and the total of drainage fixture units connected thereto in accordance with Table 906.1, but in no case shall the diameter be less than one - half the diameter of the drain served or less than 1 1 / 4 inches (32 mm). TABLE 906.1 SIZE AND DEVELOPED LENGTH OF STACK VENTS AND VENT STACKS DIAMETER OF SOIL OR WASTE STACK (inches) TOTAL FIXTURE UNITS BEING VENTED (dfu) MAXIMUM DEVELOPED LENGTH OF VENT (f eet) a DIAMETER OF VENT (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 5 6 8 10 12 1 1 / 4 2 30 — — — — — — — — — — 1 1 / 2 8 50 150 1 1 / 2 10 30 100 2 12 — 75 200 — — — — — — — — 2 20 30 50 150 — 2 1 / 2 42 26 30 100 300 3 10 — 42 150 360 1,040 — — — — — — 3 21 32 110 270 810 3 53 27 94 230 680 3 102 — 25 86 210 620 — — — — — — 4 43 — 35 85 250 980 4 140 — 27 65 200 750 4 320 — — 23 55 170 640 — — — — — VENTS 9 - 4 2022 NEW YORK CITY PLUMBING CODE 4 540 21 50 150 580 — 5 190 28 82 320 990 5 490 — — — 21 63 250 760 — — — — 5 940 18 53 210 670 5 1,400 16 49 190 590 6 500 — — — — 33 130 400 1,000 — — — 6 1,100 — 26 100 310 780 6 2,000 — 22 84 260 660 6 2,900 — — — — 20 77 240 600 — — — 8 1,800 — 31 95 240 940 8 3,400 — 24 73 190 729 8 5,600 — — — — — 20 62 160 610 — — 8 7,600 18 56 140 560 — 10 4,000 — 31 78 310 960 10 7,200 — — — — — — 24 60 240 740 — 10 11,000 20 51 200 630 10 15,000 18 46 180 571 12 7,300 — — — — — — — 31 120 380 940 12 13,000 — 24 94 300 720 12 20,000 — 20 79 250 610 12 26,000 — — — — — — — 18 72 230 500 15 15,000 — 40 130 310 15 25,000 — 31 96 240 15 38,000 — — — — — — — — 26 81 200 15 50,000 24 74 180 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm. a. The developed length shall be measured from the vent connection to the open air. 906.2 Vents other than stack vents or vent stacks. The diameter of individual vents, branch vents, circuit vents and relief vents shall be at least one - half the required diameter of the drain served. The required size of the drain shall be determined in accordance with Table 710.1(2). Vent pipes shall not be less than 1 1 / 4 inches (32 mm) in diameter. Vents shall be sized in accordance with Table 906.1 utilizing the drainage fixture units and the corresponding VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 5 developed length. Relief vents for soil and waste stacks in buildings having more than 10 branch intervals shall be sized in accordance with Section 908.2. 906.3 Developed length. The developed length of individual, branch, circuit and relief vents shall be measured from the farthest point of vent connection to the drainage system to the point of connection to the vent stack, stack vent or termination outside of the building. 906.4 Multiple branch vents. Where multiple branch vents are connected to a common branch vent, the common branch vent shall be sized in accordance with this section based on the size of the co mmon horizontal drainage branch that is or would be required to serve the total drainage fixture unit load being vented. 906.5 Ejector vents. Ejector vent sizes shall be determined in accordance with Sections 906.5.1 and 906.5.2. 906.5.1 Sewage pumps and s ewage ejectors other than pneumatic. Drainage piping below sewer level shall be vented in the same manner as that of a gravity system. Building sump vent sizes for sumps with sewage pumps or sewage ejectors, other than pneumatic, shall be determined in acc ordance with Table 906.5.1. Where a building sump vent connects to a sanitary vent system, the sanitary branch vent shall be at least 3 inches (76 mm) in diameter. TABLE 906.5.1 SIZE AND LENGTH OF SUMP VENTS DISCHARGE CAPACITY OF PUMP (gpm) MAXIMUM DEVELOP ED LENGTH OF VENT (feet) a Diameter of vent (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 10 No limit b No limit No limit No limit No limit No limit 20 270 No limit No limit No limit No limit No limit 40 72 160 No limit No limit No limit No limit 60 31 75 270 No limit No limit No limit 80 16 41 150 380 No limit No limit 100 10 c 25 97 250 No limit No limit 150 Not permitted 10 c 44 110 370 No limit 200 Not permitted Not permitted 20 60 210 No limit 250 Not permitted Not permitted 10 36 132 No limit 300 Not permitted Not permitted 10 c 22 88 380 400 Not permitted Not permitted Not permitted 10 c 44 210 500 Not permitted Not permitted Not permitted Not permitted 24 130 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 gallon per minute = 3.785 L/m. a. Developed length plus an appropriate allowance for entrance losses and friction due to fittings, changes in direction and dia meter. Suggested allowances shall be obtained from NBS Monograph 31 or other approved sources. An allowance of 50 percent of the de veloped length shall be assumed if a more precise value is not available. b. Actual values greater than 500 feet. c. Less than 10 feet. 906.5.2 Pneumatic sewage ejectors. The air pressure relief pipe from a pneumatic sewage ejector shall be con- nected to a n independent vent stack terminating as required for vent extensions through the roof. The relief pipe VENTS 9 - 6 2022 NEW YORK CITY PLUMBING CODE shall be sized to relieve air pressure inside the ejector to atmospheric pressure, but shall be not less than 1 1 / 2 inches (38 mm) in size. SECTION PC 907 VENTS FOR STACK OFFSETS 907.1 Vent for horizontal offset of drainage stack. Horizontal offsets of drainage stacks shall be vented where five or more branch intervals are located above the offset. The offset shall be vented by venting the upper section of the drainage stack and the lower section of the drainage stack. 907.2 Upper section. The upper section of the drainage stack shall be vented as a separate stack with a vent stack connection installed in accordance with Section 904.4. The offset shall be considered the base of the stack. 907.3 Lower section. The lower section of the drainage stack shall be vented by a yoke vent connecting between the offset and the next lower horizontal branch. The yoke vent connection shall be permitted to be a vertical extension of the drainage stack. The size of the yoke vent and connection shall be a minimum of the size required for the vent stack of the drainage stack. SECTION PC 908 RELIEF VENTS — STACKS OF MORE THAN 10 BRANCH INTERVALS 908.1 Where required. Soil and w aste stacks in buildings having more than 10 branch intervals shall be provided with a relief vent at each tenth interval installed, beginning with the top floor. 908.2 Size and connection. The size of the relief vent shall be equal to the size of the vent stack to which it connects. The lower end of each relief vent shall connect to the soil or waste stack through a wye below the horizontal branch serving the floor, and the upper end shall connect to the vent stack through a tee or inverted wye not less th an 3 feet (914 mm) above the floor. SECTION PC 909 FIXTURE VENTS 909.1 Distance of trap from vent. Each fixture trap shall have a protecting vent located so that the slope and the developed length in the fixture drain from the trap weir to the vent fitting are within the requirements set forth in Table 909.1. Exception: The developed length of the fixture drain from the trap weir to the vent fitting for self - siphoning fix- tures, such as water closets, shall not be limited. TABLE 909.1 MAXIMUM DISTANCE OF FIX TURE TRAP FROM VENT SIZE OF TRAP (inches) SLOPE (inch per foot) DISTANCE FROM TRAP (feet) 1 1 / 4 1 / 4 5 1 1 / 2 1 / 4 6 2 1 / 4 8 3 1 / 8 12 4 1 / 8 16 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 inch per foot = 83.3 mm/m. VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 7 909.2 Venting of fixture drains. The vent for a fixture drain, except where serving a fixture with integral traps, such as water closets, shall connect above the weir of the fixture trap being vented. 909.3 Crown vent. A vent shall not be installed within two pipe diameters of the trap weir . SECTION PC 910 INDIVIDUAL VENT 910.1 Individual vent permitted. Each trap and trapped fixture is permitted to be provided with an individual vent. The individual vent shall connect to the fixture drain of the trap or trapped fixture being vente d in accordance with section 909.1, but at a distance not to exceed 16 feet (4876 mm). 910.2 Floor drain vents. No vents will be required for piping serving floor drains when the floor drain is located not more than 15 feet (4572 mm) from the vented line to which it connects. SECTION PC 911 COMMON VENT 911.1 Individual vent as common vent. An individual vent is permitted to vent two traps or trapped fixtures as a common vent. The traps or trapped fixtures being common vented shall be located on the same floor level. 911.2 Connection at the same level. Where the fixture drains being common vented connect at the same level, the vent connection shall be at the interconnection of the fixture drains. Exception: Where wet vents are permitted by this code, the wet vent connection may be located downstream of the interconnection. 911.3 Connection at different levels. Where the fixture drains connect at different levels, the vent shall connect as a vertical extension of the vertical drain. The vertical drain p ipe connecting the two fixture drains shall be considered the vent for the lower fixture drain, and shall be sized in accordance with Table 911.3 . The upper fixture shall not be a water closet. TABLE 911.3 COMMON VENT SIZES PIPE SIZE (inches) MAXIMUM DISCH ARGE FROM UPPER FIXTURE DRAIN (dfu) 1 1 / 2 1 2 4 2 1 / 2 to 3 6 For SI: 1 inch = 25.4 mm. SECTION PC 912 WET VENTING 912.1 Horizontal wet vent permitted. Any combination of fixtures within one bathroom group located in the same room is permitted to be vented by a horizontal wet vent. The wet vent shall be considered the vent for the fixtures and shall extend from the connection of the dry vent along the direction of the flow in the drain pipe to the most down- stream fixture drain connection to the horizo ntal branch drain. Each wet - vented fixture drain shall connect inde- pendently to the horizontal wet vent. Only the fixtures within the bathroom groups shall connect to the wet - vented horizontal branch drain. Any additional fixtures shall discharge downstrea m of the horizontal wet vent. 912.1.1 Vertical wet vent permitted. Any combination of fixtures within one bathroom group is permitted to be vented by a vertical wet vent. The vertical wet vent shall be considered the vent for the fixtures and shall extend VENTS 9 - 8 2022 NEW YORK CITY PLUMBING CODE from the connection of the dry vent down to the lowest fixture drain connection. Each wet - vented fixture shall connect independently to the vertical wet vent. Fixture drains shall connect above or at the same elevation as the water closet fixture drain. Th e dry - vent connection to the vertical wet vent shall be an individual or common vent serving one or two fixtures. 912.2 Dry - vent connection. The required dry - vent connection for wet - vented systems shall comply with Sections 912.2.1 and 912.2.2. 912.2.1 Hor izontal wet vent. The dry - vent connection for a horizontal wet - vent system shall be an individual vent or a common vent for any bathroom group fixture, except an emergency floor drain. Where the dry - vent connects to a water closet fixture drain, the drain shall connect horizontally to the horizontal wet - vent system. Not more than one wet - vented fixture drain shall discharge upstream of the dry - vented fixture drain connection. 912.2.2 Vertical wet vent. The dry - vent connection for a vertical wet - vent system shall be an individual vent or common vent for the most upstream fixture drain. 912.3 Size. The dry vent serving the wet vent shall be sized based on the largest required diameter of pipe within the wet - vent system served by the dry vent. The wet vent shal l be of a size not less than that specified in Table 912.3, based on the fixture unit discharge to the wet vent. TABLE 912.3 WET VENT SIZE MINIMUM WET VENT PIPE SIZE (inches) MAXIMUM DRAINAGE FIXTURE UNIT LOAD (dfu) 2 4 2 1 / 2 6 3 12 For SI: 1 inch = 25.4 mm. SECTION PC 913 RESERVED SECTION PC 914 CIRCUIT VENTING 914.1 Circuit vent permitted. A maximum of eight fixtures connected to a horizontal branch drain shall be permitted to be circuit vented. Each fixture drain shall connect horizontally to the h orizontal branch being circuit vented. The horizontal branch drain shall be classified as a vent from the most downstream fixture drain connection to the most upstream fixture drain connection to the horizontal branch. 914.1.1 Multiple circuit - vented branc hes. Circuit - vented horizontal branch drains are permitted to be connected together. Each group of a maximum of eight fixtures shall be considered a separate circuit vent and shall conform to the requirements of this section. 914.2 Vent connection. The cir cuit vent connection shall be located between the two most upstream fixture drains. The vent shall connect to the horizontal branch and shall be installed in accordance with Section 905. The circuit vent pipe shall not receive the discharge of any soil or waste. 914.3 Slope and size of horizontal branch. The slope of the vent section of the horizontal branch drain shall be not greater than one unit vertical in 12 units horizontal (8.3 - percent slope). The entire length of the vent section of the horizontal branch drain shall be sized for the total drainage discharge to the branch. VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 9 914.3.1 Size of multiple circuit vent. Each separate circuit - vented horizontal branch that is interconnected shall be sized independently in accordance with Section 914.3 . The dow nstream circuit - vented horizontal branch shall be sized for the total discharge into the branch, including the upstream branches and the fixtures within the branch. 914.4 Relief vent. A relief vent shall be provided for circuit - vented horizontal branches r eceiving the discharge of four or more water closets and connecting to a drainage stack that receives the discharge of soil or waste from upper horizontal branches. 914.4.1 Connection and installation. The relief vent shall connect to the horizontal branch drain between the stack and the most downstream fixture drain of the circuit vent. The relief vent shall be installed in accordance with Section 905. 914.4.2 Fixture drain or branch. The relief vent is permitted to be a fixture drain or fixture branch for fixtures located within the same branch interval as the circuit - vented horizontal branch. The maximum discharge to a relief vent shall be four fixture units. 914.5 Additional fixtures. Fixtures, other than the circuit - vented fixtures, are permitted to dis charge to the horizontal branch drain. Such fixtures shall be located on the same floor as the circuit - vented fixtures and shall be either individ- ually or common vented. SECTION PC 915 COMBINATION WASTE AND VENT SYSTEM 915.1 Types of fixtures. A combination waste and vent system shall not serve fixtures other than floor drains, lava- tories and drinking fountains. Combination waste and vent systems shall not receive the discharge from a food waste disposer or clinical sink. 915.2 Installation. The c ombination waste and vent system shall be a horizontal piping system. The only vertical pipe of a combination waste and vent system shall be the connection between the fixture drain and the horizontal combi- nation waste and vent pipe. The vertical distance shall not exceed 8 feet (2438 mm). 915.2.1 Slope. The slope at a horizontal combination waste and vent pipe shall not exceed one - half unit vertical in 12 units horizontal (4 - percent slope) and shall not be less than indicated in Table 704.1. 915.2.2 Size a nd length. The size of a combination waste and vent pipe shall be not less than that indicated in Table 915.2.2. The horizontal length of a combination waste and vent system shall be unlimited. TABLE 915.2.2 SIZE OF COMBINATION WASTE AND VENT PIPE DIAMETER PIPE (inches) MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS (dfu) Connecting to a horizontal branch or stack Connecting to a building drain or building subdrain 2 3 4 2 1 / 2 6 26 3 12 31 4 20 50 5 160 250 6 360 575 For SI: 1 inch = 25.4 mm. VENTS 9 - 10 2022 NEW YORK CITY PLUMBING CODE 915.2.3 Connection. The combination waste and vent system shall be provided with a dry vent connected at any point within the system or the system shall connect to a horizontal drain that serves vented fixtures located on the same floor . Combination waste and vent systems connecting to building drains receiving only the discharge from one or more stacks shall be provided with a dry vent. The vent connection to the combination waste and vent pipe shall extend vertically to a point not less than 6 inches (152 mm) above the flood level rim of the highest fixture being vented before offsetting horizontally. 915.2.4 Vent size. The vent shall be sized for the total drainage fixture unit load in accordance with Section 906.2 . 915.2.5 Fixture branch or drain. The fi xture branch or fixture drain shall connect to the combination waste and vent within a distance specified in Table 909.1. The combination waste and vent pipe shall be considered the vent for the fixture . SECTION PC 916 ISLAND FIXTURE VENTING 916.1 Limitati on. Island fixture venting shall not be permitted for fixtures other than sinks and lavatories. Residential kitchen sinks with a dishwasher waste connection, a food waste disposer , or both, in combination with the kitchen sink waste, shall be permitted to be vented in accordance with this section. 916.2 Vent connection. The island fixture vent shall connect to the fixture drain as required for an individual or common vent. The vent shall rise vertically to above the drainage outlet of the fixture being vent ed before offsetting horizontally or vertically downward. The vent or branch vent for multiple island fixture vents shall extend to a point not less than 6 inches (152 mm) above the highest island fixture being vented before connecting to the outside vent terminal. 916.3 Vent installation below the fixture flood level rim. The vent located below the flood level rim of the fixture being vented shall be installed as required for drainage piping in accordance with Chapter 7, except for sizing. The vent shall b e sized in accordance with Section 906.2 . The lowest point of the island fixture vent shall connect full size to the drainage system. The connection shall be to a vertical drain pipe or to the top half of a horizontal drain pipe. Cleanouts shall be provided in the island fixture vent to permit rodding of all vent piping located below the flood level rim of the fixtures. Rodding in both directions shall be permitted through a cleanout. SECTION PC 917 RESERVED SECTION PC 918 RESERVED SECTION PC 919 ENG INEERED VENT SYSTEMS 919.1 General. Engineered vent systems shall comply with this section and Section 28 - 113.2.2 of the Administrative Code . 919.2 Individual branch fixture and individual fixture header vents. The maximum developed length of individual fi xture vents to vent branches and vent headers shall be determined in accordance with Table 919.2 for the minimum pipe diameters at the indicated vent airflow rates. The individual vent airflow rate shall be determined in accordance with the following: Q h,b = N n,b Q ν (Equation 9 - 1) For SI: Q h , b = N n , b Q ν (0.4719 L/s) where: VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 11 N n , b = Number of fixtures per header (or vent branch) ÷ total number of fixtures connected to vent stack. Q h , b = Vent branch or vent header airflow rate (cfm). Q ν = Total vent stack airflow rate (cfm). Q ν (gpm) = 27.8 r s 2/3 (1 – rs ) D 8/3 Q ν (cfm) = 0.134 Q ν (gpm) where: D = Drainage stack diameter (inches). Q w = Design discharge load (gpm). r s = Waste water flow area to total area. = Q w / 27.8 D 8/3 Individual vent airflow rates are obtained by equally distributing Q h,b into one - half the total number of fixtures on the branch or header for more than two fixtures; for an odd number of total fixtures, decrease by one; for one fixture, apply the full value of Q h, b . Individual vent developed length shall be increased by 20 percent of the distance from the vent stack to the fixture vent connecti on on the vent branch or header. TABLE 919.2 MINIMUM DIAMETER AND MAXIMUM LENGTH OF INDIVIDUAL BRANCH FIXTURE VENTS AND INDIVIDUAL FIXTURE HEADER VENTS FOR SMOOTH PIPES DIAMETER OF VENT PIPE (inches) INDIVIDUAL VENT AIRFLOW RATE (cubic feet per minute) Maximum developed length of vent (feet) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 1 / 2 95 25 13 8 5 4 3 2 1 1 1 1 1 1 1 1 1 1 1 1 3 / 4 100 88 47 30 20 15 10 9 7 6 5 4 3 3 3 2 2 2 2 1 1 — — 100 94 65 48 37 29 24 20 17 14 12 11 9 8 7 7 6 6 1 1 / 4 — — — — — — — 100 87 73 62 53 46 40 36 32 29 26 23 21 1 1 / 2 — — — — — — — — — — — 100 96 84 75 65 60 54 49 45 2 — — — — — — — — — — — — — — — — — — — 100 For SI: 1 inch = 25.4 mm, 1 cubic foot per minute = 0.4719 L/s, 1 foot = 304.8 mm. 919.3 A licensed professional engineer shall certify design. An engineer shall also inspect and certify the system upon completion of the system. SECTION PC 920 COMPUTERIZED VENT DESIGN 920.1 Design of vent system. The sizing, design and layout of the vent system shall be permitted to be determined by computer program design methods which shall be approved by the commissioner to insure compliance with the minimum standards of this code . 920.2 System capacity. The vent system shall be based on the air capacit y requirements of the drainage system under a peak load condition. VENTS 9 - 12 2022 NEW YORK CITY PLUMBING CODE 920.3 Design shall be certified by a licensed professional engineer. An engineer shall also inspect and certify the system upon completion of the system.03.5.1 New vent terminals. An open vent terminal from a drainage system of the new or altered building shall not be located directly beneath any door, o perable window, or other air intake opening of the building or of an adjacent building, and any such vent terminal shall not be within 10 feet (3048 mm) horizontally of such an opening unless it is at least 3 feet (914 mm) above the top of such opening. Wh en the consent of the owner of an adjoining taller build - ing is obtained, the owner of the new or altered building shall be permitted to carry the new vent stack, with adequate support, to a level above the higher existing roof. 903.5.2 New openings. A doo r, operable window, or other air intake opening of the new or altered building shall not be located within 10 feet (3048 mm) horizontally from an open vent terminal from a drainage system of an existing adjacent building unless the existing terminal is at least 3 feet (914 mm) above such opening. Whenever necessary, the owner of the new building shall at his or her own expense, and with approval of the adjoining owner, offset the vent stack of the adjacent existing building to a distance of 10 feet (3048 mm ) or more from such openings, or shall extend such vent stack to a height of at least 3 feet (924 mm) above the topmost opening. 903.6 Reserved. 903.7 Reserved. SECTION PC 904 OUTDOOR VENT EXTENSIONS 904 .1 Required vent extension. The vent system serving each building drain shall have not less than one vent pipe that extends to the outdoors. 904. 1.1 Installation. The required vent shall be a dry vent that connects to the building drain or an extension of a drain that connects to the building drain. Such vent shall not be an island fixture vent as allowed by Section 916. 904.1.2 Size. The required vent shall be sized in accordance with Section 906.2 based on the required size of the building drain. 904.2 Vent stack required. A vent stack shall be required for every drainage stack that has three branch intervals or more . 904.3 Vent termination. Vent stacks or stack vents shall terminate outdoors above the roof or to the stack vent portion of the soil or waste stack, at least 6 inches (152 mm) above the flood level of the highest fixture connection discharging into the soil or waste stack. 904.4 Vent connection at base. Vent stacks shall connect to the base of the drainage stack. The vent stack shall co nnect at or below the lowest horizontal branch. Where the vent stack connects to the building drain, the connection shall be located downstream of the drainage stack and within a distance of 10 times the diameter of the drainage stack. 904.5 Vent headers. Stack vents and vent stacks connected into a common vent header at the top of the stacks and extending to the open air above the roof at one point shall be sized in accordance with the requirements of Section 906.1, but shall not be smaller than the smalle st stack vent . The number of fixture units shall be the sum of all fixture units on all stacks connected thereto, and the developed length shall be the longest vent length from the intersection at the base of the most distant stack to the vent terminal in the open air, as a direct extension of one stack. 904.6 Sub - stack connections. Where it is desired to terminate stacks at a point below the roof terminus of the main vent stack, the sub - stack may connect to the main vent stack provided the portion of the m ain vent stack above the connection is sized for the total fixture unit load connected thereto, and for the maximum developed length of the stack or sub - stack. SECTION PC 905 VENT CONNECTIONS AND GRADES 905.1 Connection. Individual , branch and circuit vents shall connect to a vent stack, stack vent, or extend to the open air above the roof . VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 3 905.2 Grade. Vent and branch vent pipes shall be so graded and connected as to drain back to the drainage pipe by gravity. 905.3 Vent connection to drainage system. Every dry vent connecting to a horizontal drain shall connect above the centerline of the horizontal drain pipe. 905.4 Reserved. 905.5 Height above fixtures. A connection between a vent pipe and a vent stack or stack vent shall be made at not less than 6 inches (152 mm) above the flood level rim of the highest fixture served by the vent. Horizontal vent pipes forming branch vents, relief vents or loop vents shall be located not less than 6 inches (152 mm) above the flood level rim of the highest fix ture served. 905.6 Vent for future fixtures. Where the drainage piping has been roughed - in for future fixtures, a rough - in con- nection for a vent shall be installed. The vent size shall be not less than one - half the diameter of the rough - in drain to be serv ed. The vent rough - in shall connect to the vent system, or shall be vented by other means as provided for in this chapter. The connection shall be identified to indicate that it is a vent. SECTION PC 906 VENT PIPE SIZING 906.1 Size of stack vents and vent stacks. The minimum required diameter of stack vents and vent stacks shall be determined from the developed length and the total of drainage fixture units connected thereto in accordance with Table 906.1, but in no case shall the diameter be less than one - half the diameter of the drain served or less than 1 1 / 4 inches (32 mm). TABLE 906.1 SIZE AND DEVELOPED LENGTH OF STACK VENTS AND VENT STACKS DIAMETER OF SOIL OR WASTE STACK (inches) TOTAL FIXTURE UNITS BEING VENTED (dfu) MAXIMUM DEVELOPED LENGTH OF VENT (f eet) a DIAMETER OF VENT (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 5 6 8 10 12 1 1 / 4 2 30 — — — — — — — — — — 1 1 / 2 8 50 150 1 1 / 2 10 30 100 2 12 — 75 200 — — — — — — — — 2 20 30 50 150 — 2 1 / 2 42 26 30 100 300 3 10 — 42 150 360 1,040 — — — — — — 3 21 32 110 270 810 3 53 27 94 230 680 3 102 — 25 86 210 620 — — — — — — 4 43 — 35 85 250 980 4 140 — 27 65 200 750 4 320 — — 23 55 170 640 — — — — — VENTS 9 - 4 2022 NEW YORK CITY PLUMBING CODE 4 540 21 50 150 580 — 5 190 28 82 320 990 5 490 — — — 21 63 250 760 — — — — 5 940 18 53 210 670 5 1,400 16 49 190 590 6 500 — — — — 33 130 400 1,000 — — — 6 1,100 — 26 100 310 780 6 2,000 — 22 84 260 660 6 2,900 — — — — 20 77 240 600 — — — 8 1,800 — 31 95 240 940 8 3,400 — 24 73 190 729 8 5,600 — — — — — 20 62 160 610 — — 8 7,600 18 56 140 560 — 10 4,000 — 31 78 310 960 10 7,200 — — — — — — 24 60 240 740 — 10 11,000 20 51 200 630 10 15,000 18 46 180 571 12 7,300 — — — — — — — 31 120 380 940 12 13,000 — 24 94 300 720 12 20,000 — 20 79 250 610 12 26,000 — — — — — — — 18 72 230 500 15 15,000 — 40 130 310 15 25,000 — 31 96 240 15 38,000 — — — — — — — — 26 81 200 15 50,000 24 74 180 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm. a. The developed length shall be measured from the vent connection to the open air. 906.2 Vents other than stack vents or vent stacks. The diameter of individual vents, branch vents, circuit vents and relief vents shall be at least one - half the required diameter of the drain served. The required size of the drain shall be determined in accordance with Table 710.1(2). Vent pipes shall not be less than 1 1 / 4 inches (32 mm) in diameter. Vents shall be sized in accordance with Table 906.1 utilizing the drainage fixture units and the corresponding VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 5 developed length. Relief vents for soil and waste stacks in buildings having more than 10 branch intervals shall be sized in accordance with Section 908.2. 906.3 Developed length. The developed length of individual, branch, circuit and relief vents shall be measured from the farthest point of vent connection to the drainage system to the point of connection to the vent stack, stack vent or termination outside of the building. 906.4 Multiple branch vents. Where multiple branch vents are connected to a common branch vent, the common branch vent shall be sized in accordance with this section based on the size of the co mmon horizontal drainage branch that is or would be required to serve the total drainage fixture unit load being vented. 906.5 Ejector vents. Ejector vent sizes shall be determined in accordance with Sections 906.5.1 and 906.5.2. 906.5.1 Sewage pumps and s ewage ejectors other than pneumatic. Drainage piping below sewer level shall be vented in the same manner as that of a gravity system. Building sump vent sizes for sumps with sewage pumps or sewage ejectors, other than pneumatic, shall be determined in acc ordance with Table 906.5.1. Where a building sump vent connects to a sanitary vent system, the sanitary branch vent shall be at least 3 inches (76 mm) in diameter. TABLE 906.5.1 SIZE AND LENGTH OF SUMP VENTS DISCHARGE CAPACITY OF PUMP (gpm) MAXIMUM DEVELOP ED LENGTH OF VENT (feet) a Diameter of vent (inches) 1 1 / 4 1 1 / 2 2 2 1 / 2 3 4 10 No limit b No limit No limit No limit No limit No limit 20 270 No limit No limit No limit No limit No limit 40 72 160 No limit No limit No limit No limit 60 31 75 270 No limit No limit No limit 80 16 41 150 380 No limit No limit 100 10 c 25 97 250 No limit No limit 150 Not permitted 10 c 44 110 370 No limit 200 Not permitted Not permitted 20 60 210 No limit 250 Not permitted Not permitted 10 36 132 No limit 300 Not permitted Not permitted 10 c 22 88 380 400 Not permitted Not permitted Not permitted 10 c 44 210 500 Not permitted Not permitted Not permitted Not permitted 24 130 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 gallon per minute = 3.785 L/m. a. Developed length plus an appropriate allowance for entrance losses and friction due to fittings, changes in direction and dia meter. Suggested allowances shall be obtained from NBS Monograph 31 or other approved sources. An allowance of 50 percent of the de veloped length shall be assumed if a more precise value is not available. b. Actual values greater than 500 feet. c. Less than 10 feet. 906.5.2 Pneumatic sewage ejectors. The air pressure relief pipe from a pneumatic sewage ejector shall be con- nected to a n independent vent stack terminating as required for vent extensions through the roof. The relief pipe VENTS 9 - 6 2022 NEW YORK CITY PLUMBING CODE shall be sized to relieve air pressure inside the ejector to atmospheric pressure, but shall be not less than 1 1 / 2 inches (38 mm) in size. SECTION PC 907 VENTS FOR STACK OFFSETS 907.1 Vent for horizontal offset of drainage stack. Horizontal offsets of drainage stacks shall be vented where five or more branch intervals are located above the offset. The offset shall be vented by venting the upper section of the drainage stack and the lower section of the drainage stack. 907.2 Upper section. The upper section of the drainage stack shall be vented as a separate stack with a vent stack connection installed in accordance with Section 904.4. The offset shall be considered the base of the stack. 907.3 Lower section. The lower section of the drainage stack shall be vented by a yoke vent connecting between the offset and the next lower horizontal branch. The yoke vent connection shall be permitted to be a vertical extension of the drainage stack. The size of the yoke vent and connection shall be a minimum of the size required for the vent stack of the drainage stack. SECTION PC 908 RELIEF VENTS — STACKS OF MORE THAN 10 BRANCH INTERVALS 908.1 Where required. Soil and w aste stacks in buildings having more than 10 branch intervals shall be provided with a relief vent at each tenth interval installed, beginning with the top floor. 908.2 Size and connection. The size of the relief vent shall be equal to the size of the vent stack to which it connects. The lower end of each relief vent shall connect to the soil or waste stack through a wye below the horizontal branch serving the floor, and the upper end shall connect to the vent stack through a tee or inverted wye not less th an 3 feet (914 mm) above the floor. SECTION PC 909 FIXTURE VENTS 909.1 Distance of trap from vent. Each fixture trap shall have a protecting vent located so that the slope and the developed length in the fixture drain from the trap weir to the vent fitting are within the requirements set forth in Table 909.1. Exception: The developed length of the fixture drain from the trap weir to the vent fitting for self - siphoning fix- tures, such as water closets, shall not be limited. TABLE 909.1 MAXIMUM DISTANCE OF FIX TURE TRAP FROM VENT SIZE OF TRAP (inches) SLOPE (inch per foot) DISTANCE FROM TRAP (feet) 1 1 / 4 1 / 4 5 1 1 / 2 1 / 4 6 2 1 / 4 8 3 1 / 8 12 4 1 / 8 16 For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 inch per foot = 83.3 mm/m. VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 7 909.2 Venting of fixture drains. The vent for a fixture drain, except where serving a fixture with integral traps, such as water closets, shall connect above the weir of the fixture trap being vented. 909.3 Crown vent. A vent shall not be installed within two pipe diameters of the trap weir . SECTION PC 910 INDIVIDUAL VENT 910.1 Individual vent permitted. Each trap and trapped fixture is permitted to be provided with an individual vent. The individual vent shall connect to the fixture drain of the trap or trapped fixture being vente d in accordance with section 909.1, but at a distance not to exceed 16 feet (4876 mm). 910.2 Floor drain vents. No vents will be required for piping serving floor drains when the floor drain is located not more than 15 feet (4572 mm) from the vented line to which it connects. SECTION PC 911 COMMON VENT 911.1 Individual vent as common vent. An individual vent is permitted to vent two traps or trapped fixtures as a common vent. The traps or trapped fixtures being common vented shall be located on the same floor level. 911.2 Connection at the same level. Where the fixture drains being common vented connect at the same level, the vent connection shall be at the interconnection of the fixture drains. Exception: Where wet vents are permitted by this code, the wet vent connection may be located downstream of the interconnection. 911.3 Connection at different levels. Where the fixture drains connect at different levels, the vent shall connect as a vertical extension of the vertical drain. The vertical drain p ipe connecting the two fixture drains shall be considered the vent for the lower fixture drain, and shall be sized in accordance with Table 911.3 . The upper fixture shall not be a water closet. TABLE 911.3 COMMON VENT SIZES PIPE SIZE (inches) MAXIMUM DISCH ARGE FROM UPPER FIXTURE DRAIN (dfu) 1 1 / 2 1 2 4 2 1 / 2 to 3 6 For SI: 1 inch = 25.4 mm. SECTION PC 912 WET VENTING 912.1 Horizontal wet vent permitted. Any combination of fixtures within one bathroom group located in the same room is permitted to be vented by a horizontal wet vent. The wet vent shall be considered the vent for the fixtures and shall extend from the connection of the dry vent along the direction of the flow in the drain pipe to the most down- stream fixture drain connection to the horizo ntal branch drain. Each wet - vented fixture drain shall connect inde- pendently to the horizontal wet vent. Only the fixtures within the bathroom groups shall connect to the wet - vented horizontal branch drain. Any additional fixtures shall discharge downstrea m of the horizontal wet vent. 912.1.1 Vertical wet vent permitted. Any combination of fixtures within one bathroom group is permitted to be vented by a vertical wet vent. The vertical wet vent shall be considered the vent for the fixtures and shall extend VENTS 9 - 8 2022 NEW YORK CITY PLUMBING CODE from the connection of the dry vent down to the lowest fixture drain connection. Each wet - vented fixture shall connect independently to the vertical wet vent. Fixture drains shall connect above or at the same elevation as the water closet fixture drain. Th e dry - vent connection to the vertical wet vent shall be an individual or common vent serving one or two fixtures. 912.2 Dry - vent connection. The required dry - vent connection for wet - vented systems shall comply with Sections 912.2.1 and 912.2.2. 912.2.1 Hor izontal wet vent. The dry - vent connection for a horizontal wet - vent system shall be an individual vent or a common vent for any bathroom group fixture, except an emergency floor drain. Where the dry - vent connects to a water closet fixture drain, the drain shall connect horizontally to the horizontal wet - vent system. Not more than one wet - vented fixture drain shall discharge upstream of the dry - vented fixture drain connection. 912.2.2 Vertical wet vent. The dry - vent connection for a vertical wet - vent system shall be an individual vent or common vent for the most upstream fixture drain. 912.3 Size. The dry vent serving the wet vent shall be sized based on the largest required diameter of pipe within the wet - vent system served by the dry vent. The wet vent shal l be of a size not less than that specified in Table 912.3, based on the fixture unit discharge to the wet vent. TABLE 912.3 WET VENT SIZE MINIMUM WET VENT PIPE SIZE (inches) MAXIMUM DRAINAGE FIXTURE UNIT LOAD (dfu) 2 4 2 1 / 2 6 3 12 For SI: 1 inch = 25.4 mm. SECTION PC 913 RESERVED SECTION PC 914 CIRCUIT VENTING 914.1 Circuit vent permitted. A maximum of eight fixtures connected to a horizontal branch drain shall be permitted to be circuit vented. Each fixture drain shall connect horizontally to the h orizontal branch being circuit vented. The horizontal branch drain shall be classified as a vent from the most downstream fixture drain connection to the most upstream fixture drain connection to the horizontal branch. 914.1.1 Multiple circuit - vented branc hes. Circuit - vented horizontal branch drains are permitted to be connected together. Each group of a maximum of eight fixtures shall be considered a separate circuit vent and shall conform to the requirements of this section. 914.2 Vent connection. The cir cuit vent connection shall be located between the two most upstream fixture drains. The vent shall connect to the horizontal branch and shall be installed in accordance with Section 905. The circuit vent pipe shall not receive the discharge of any soil or waste. 914.3 Slope and size of horizontal branch. The slope of the vent section of the horizontal branch drain shall be not greater than one unit vertical in 12 units horizontal (8.3 - percent slope). The entire length of the vent section of the horizontal branch drain shall be sized for the total drainage discharge to the branch. VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 9 914.3.1 Size of multiple circuit vent. Each separate circuit - vented horizontal branch that is interconnected shall be sized independently in accordance with Section 914.3 . The dow nstream circuit - vented horizontal branch shall be sized for the total discharge into the branch, including the upstream branches and the fixtures within the branch. 914.4 Relief vent. A relief vent shall be provided for circuit - vented horizontal branches r eceiving the discharge of four or more water closets and connecting to a drainage stack that receives the discharge of soil or waste from upper horizontal branches. 914.4.1 Connection and installation. The relief vent shall connect to the horizontal branch drain between the stack and the most downstream fixture drain of the circuit vent. The relief vent shall be installed in accordance with Section 905. 914.4.2 Fixture drain or branch. The relief vent is permitted to be a fixture drain or fixture branch for fixtures located within the same branch interval as the circuit - vented horizontal branch. The maximum discharge to a relief vent shall be four fixture units. 914.5 Additional fixtures. Fixtures, other than the circuit - vented fixtures, are permitted to dis charge to the horizontal branch drain. Such fixtures shall be located on the same floor as the circuit - vented fixtures and shall be either individ- ually or common vented. SECTION PC 915 COMBINATION WASTE AND VENT SYSTEM 915.1 Types of fixtures. A combination waste and vent system shall not serve fixtures other than floor drains, lava- tories and drinking fountains. Combination waste and vent systems shall not receive the discharge from a food waste disposer or clinical sink. 915.2 Installation. The c ombination waste and vent system shall be a horizontal piping system. The only vertical pipe of a combination waste and vent system shall be the connection between the fixture drain and the horizontal combi- nation waste and vent pipe. The vertical distance shall not exceed 8 feet (2438 mm). 915.2.1 Slope. The slope at a horizontal combination waste and vent pipe shall not exceed one - half unit vertical in 12 units horizontal (4 - percent slope) and shall not be less than indicated in Table 704.1. 915.2.2 Size a nd length. The size of a combination waste and vent pipe shall be not less than that indicated in Table 915.2.2. The horizontal length of a combination waste and vent system shall be unlimited. TABLE 915.2.2 SIZE OF COMBINATION WASTE AND VENT PIPE DIAMETER PIPE (inches) MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS (dfu) Connecting to a horizontal branch or stack Connecting to a building drain or building subdrain 2 3 4 2 1 / 2 6 26 3 12 31 4 20 50 5 160 250 6 360 575 For SI: 1 inch = 25.4 mm. VENTS 9 - 10 2022 NEW YORK CITY PLUMBING CODE 915.2.3 Connection. The combination waste and vent system shall be provided with a dry vent connected at any point within the system or the system shall connect to a horizontal drain that serves vented fixtures located on the same floor . Combination waste and vent systems connecting to building drains receiving only the discharge from one or more stacks shall be provided with a dry vent. The vent connection to the combination waste and vent pipe shall extend vertically to a point not less than 6 inches (152 mm) above the flood level rim of the highest fixture being vented before offsetting horizontally. 915.2.4 Vent size. The vent shall be sized for the total drainage fixture unit load in accordance with Section 906.2 . 915.2.5 Fixture branch or drain. The fi xture branch or fixture drain shall connect to the combination waste and vent within a distance specified in Table 909.1. The combination waste and vent pipe shall be considered the vent for the fixture . SECTION PC 916 ISLAND FIXTURE VENTING 916.1 Limitati on. Island fixture venting shall not be permitted for fixtures other than sinks and lavatories. Residential kitchen sinks with a dishwasher waste connection, a food waste disposer , or both, in combination with the kitchen sink waste, shall be permitted to be vented in accordance with this section. 916.2 Vent connection. The island fixture vent shall connect to the fixture drain as required for an individual or common vent. The vent shall rise vertically to above the drainage outlet of the fixture being vent ed before offsetting horizontally or vertically downward. The vent or branch vent for multiple island fixture vents shall extend to a point not less than 6 inches (152 mm) above the highest island fixture being vented before connecting to the outside vent terminal. 916.3 Vent installation below the fixture flood level rim. The vent located below the flood level rim of the fixture being vented shall be installed as required for drainage piping in accordance with Chapter 7, except for sizing. The vent shall b e sized in accordance with Section 906.2 . The lowest point of the island fixture vent shall connect full size to the drainage system. The connection shall be to a vertical drain pipe or to the top half of a horizontal drain pipe. Cleanouts shall be provided in the island fixture vent to permit rodding of all vent piping located below the flood level rim of the fixtures. Rodding in both directions shall be permitted through a cleanout. SECTION PC 917 RESERVED SECTION PC 918 RESERVED SECTION PC 919 ENG INEERED VENT SYSTEMS 919.1 General. Engineered vent systems shall comply with this section and Section 28 - 113.2.2 of the Administrative Code . 919.2 Individual branch fixture and individual fixture header vents. The maximum developed length of individual fi xture vents to vent branches and vent headers shall be determined in accordance with Table 919.2 for the minimum pipe diameters at the indicated vent airflow rates. The individual vent airflow rate shall be determined in accordance with the following: Q h,b = N n,b Q ν (Equation 9 - 1) For SI: Q h , b = N n , b Q ν (0.4719 L/s) where: VENTS 2022 NEW YORK CITY PLUMBING CODE 9 - 11 N n , b = Number of fixtures per header (or vent branch) ÷ total number of fixtures connected to vent stack. Q h , b = Vent branch or vent header airflow rate (cfm). Q ν = Total vent stack airflow rate (cfm). Q ν (gpm) = 27.8 r s 2/3 (1 – rs ) D 8/3 Q ν (cfm) = 0.134 Q ν (gpm) where: D = Drainage stack diameter (inches). Q w = Design discharge load (gpm). r s = Waste water flow area to total area. = Q w / 27.8 D 8/3 Individual vent airflow rates are obtained by equally distributing Q h,b into one - half the total number of fixtures on the branch or header for more than two fixtures; for an odd number of total fixtures, decrease by one; for one fixture, apply the full value of Q h, b . Individual vent developed length shall be increased by 20 percent of the distance from the vent stack to the fixture vent connecti on on the vent branch or header. TABLE 919.2 MINIMUM DIAMETER AND MAXIMUM LENGTH OF INDIVIDUAL BRANCH FIXTURE VENTS AND INDIVIDUAL FIXTURE HEADER VENTS FOR SMOOTH PIPES DIAMETER OF VENT PIPE (inches) INDIVIDUAL VENT AIRFLOW RATE (cubic feet per minute) Maximum developed length of vent (feet) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 1 / 2 95 25 13 8 5 4 3 2 1 1 1 1 1 1 1 1 1 1 1 1 3 / 4 100 88 47 30 20 15 10 9 7 6 5 4 3 3 3 2 2 2 2 1 1 — — 100 94 65 48 37 29 24 20 17 14 12 11 9 8 7 7 6 6 1 1 / 4 — — — — — — — 100 87 73 62 53 46 40 36 32 29 26 23 21 1 1 / 2 — — — — — — — — — — — 100 96 84 75 65 60 54 49 45 2 — — — — — — — — — — — — — — — — — — — 100 For SI: 1 inch = 25.4 mm, 1 cubic foot per minute = 0.4719 L/s, 1 foot = 304.8 mm. 919.3 A licensed professional engineer shall certify design. An engineer shall also inspect and certify the system upon completion of the system. SECTION PC 920 COMPUTERIZED VENT DESIGN 920.1 Design of vent system. The sizing, design and layout of the vent system shall be permitted to be determined by computer program design methods which shall be approved by the commissioner to insure compliance with the minimum standards of this code . 920.2 System capacity. The vent system shall be based on the air capacit y requirements of the drainage system under a peak load condition. VENTS 9 - 12 2022 NEW YORK CITY PLUMBING CODE 920.3 Design shall be certified by a licensed professional engineer. An engineer shall also inspect and certify the system upon completion of the system.