Chapter 1 Administration

Chapter 2 Definitions

Chapter 3 General Regulations

Chapter 4 Gas Piping Installations

Chapter 5 Chimneys and Vents

Chapter 6 Specific Appliances

Chapter 7 Reserved

Chapter 8 Referenced Standards [PDF]

Appendix A Reserved

Appendix B Reserved

Appendix C Reserved

Appendix D Reserved

Appendix E Meters and Gas Service Piping

Appendix F Plastic Fuel Gas Piping

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This chapter shall govern the design, installation, modification and maintenance of fuel gas piping systems. The scope covered by this chapter includes piping systems from the point of delivery to the connections with the equipment and includes the design, materials, components, fabrication, assembly, installation, testing, inspection, operation and maintenance of such piping systems.
Service piping includes the fuel gas piping up to the point of delivery. Meters and service piping shall comply with the requirements of Appendix E and Appendix F of this code. In addition, service piping located within buildings shall be designed and installed in accordance with the structural integrity, firestopping, and fire protection provisions of the New York City Building Code.
Underground plastic piping installed outside of buildings, shall be in compliance with Appendix E and Appendix F of this code.
In modifying or adding to existing piping systems, sizes shall be maintained in accordance with this chapter.
Where an additional appliance is to be served, the existing piping shall be checked to determine if it has adequate capacity for all appliances served. If inadequate, the existing system shall be enlarged as required or separate piping of adequate capacity shall be provided.
For other than black steel pipe, exposed piping shall be identified by a yellow label marked "Gas" in black letters. The marking shall be spaced at intervals not exceeding 5 feet (1524 mm). The marking shall not be required on pipe located in the same room as the equipment served.
Where two or more meters are installed on the same premises but supply separate consumers, the piping systems shall not be interconnected on the outlet side of the meters.
Piping from multiple meter installations shall be marked with an approved permanent identification by the installer so that the piping system supplied by each meter is readily identifiable.
All pipe utilized for the installation, extension and alteration of any piping system shall be sized to supply the full number of outlets for the intended purpose and shall be sized in accordance with Section 402.
Piping systems shall be of such size and so installed as to provide a supply of gas sufficient to meet the maximum demand without undue loss of pressure between the point of delivery and the gas utilization equipment.
The volume of gas to be provided, in cubic feet per hour, shall be determined directly from the manufacturer's input ratings of the gas utilization equipment served. Where an input rating is not indicated, the gas supplier, equipment manufacturer or a qualified agency shall be contacted, or the rating from Table 402.2 shall be used for estimating the volume of gas to be supplied. The total connected hourly load shall be used as the basis for pipe sizing, assuming that all equipment could be operating at full capacity simultaneously. Where a diversity of load can be established, pipe sizing shall be permitted to be based on such loads.
Table 402.2
Approximate Gas Input for Typical Appliances







Appliance

Input BTU/H
(Approx.)








Space Heating Units




  Hydronic boiler




    Single family

100,000


    Multifamily, per unit

60,000


  Warm-air furnace




    Single family

100,000


    Multifamily, per unit

60,000








Space and Water Heating Units




  Hydronic boiler




    Single family

120,000


    Multifamily, per unit

75,000








Water Heating Appliances




  Water heater, automatic instantaneous

35,000


    Capacity at 2 gal./minute

50,000


    Capacity at 4 gal./minute




    Capacity at 6 gal./minute

142,800


  Water heater, automatic storage, 30- to 40-gal. tank

285,000


  Water heater, automatic storage, 50-gal. tank

428,400


  Water heater, domestic, circulating or side-arm

35,000








Cooking Appliances




  Built-in oven or broiler unit, domestic

65,000


  Built-in top unit, domestic

25,000


  Range, free-standing, domestic

40,000








Other Appliances




  Barbecue

3,000


  Clothes dryer, Type 1 (domestic)

35,000


  Gas fireplace, direct vent

40,000


  Gas light

80,000


  Gas log

40,000


  Refrigerator

2,500







For SI:
1 British thermal unit per hour = 0.293 W, 1 gallon = 3.785 L, 1 gallon per minute = 3.785 L/m.
Gas piping shall be sized in accordance with one of the following:
  1. Pipe sizing tables or sizing equations in accordance with Section 402.4.
  2. The sizing tables included in a listed piping system's manufacturer's installation instructions.
  3. Other approved engineering methods.
  4. Individual outlets to gas ranges shall not be less than .75 inches (19 mm) NPS.
Where Tables 402.4(1) through 402.4(6) are used to size piping or tubing, the pipe length shall be determined in accordance with Section 402.4.1, 402.4.2 or 402.4.3.

Where Equations 4-1 and 4-2 are used to size piping or tubing, the pipe or tubing shall have smooth inside walls and the pipe length shall be determined in accordance with Section 402.4.1, 402.4.2 or 402.4.3.

>
class="uc_indent_line_1">1. Low-pressure gas equation [Less than 1.5 pounds per square inch (psi) (10.3 kPa)]:
(Equation 4-1)
2. High-pressure gas equation [1.5 psi (10.3 kPa) and above]:
(Equation 4-2)

where:

D = Inside diameter of pipe, inches (mm).
Q =Input rate appliance(s), cubic feet per hour at 60°F(16°C) and 30-inch mercury column
P1 = Upstream pressure, psia (P1 + 14.7)
P2 = Downstream pressure, psia (P2 + 14.7)
L = Equivalent length of pipe, feet
∆H = Pressure drop, inch water column (27.7 inch water column = 1 psi)

TABLE 402.4
Cr AND Y VALUES FOR NATURAL GAS AT STANDARD CONDITIONS
For SI: 1 cubic foot = 0.028 m3, 1 foot = 305 mm, 1-inch water column = 0.249 kPa, 1 pound per square inch = 6.895 kPa, 1 British thermal unit per hour = 0.293 W.












The pipe size of each section of gas piping shall be determined using the longest length of piping from the point of delivery to the most remote outlet and the load of the section.
Pipe shall be sized as follows:
  1. Pipe size of each section of the longest pipe run from the point of delivery to the most remote outlet shall be determined using the longest run of piping and the load of the section.
  2. The pipe size of each section of branch piping not previously sized shall be determined using the length of piping from the point of delivery to the most remote outlet in each branch and the load of the section.
The pipe size for each section of higher pressure gas piping shall be determined using the longest length of piping from the point of delivery to the most remote line pressure regulator. The pipe size from the line pressure regulator to each outlet shall be determined using the length of piping from the regulator to the most remote outlet served by the regulator.
The design pressure loss in any piping system under maximum probable flow conditions, from the point of delivery to the inlet connection of the equipment, shall be such that the supply pressure at the equipment is greater than the minimum pressure required for proper equipment operation.
No gas distribution piping containing gas at a pressure in excess of 1 / 2 psig (3.5 kPa gauge) shall be run within a building, except that pressure not exceeding 3 psig (20 kPa gauge) is permitted for the following uses: (a) commercial (b) industrial (c) other large volume use in which fuel requirements for boiler room equipment exceed 4,000 cubic feet per hour (113.2 m 3 /h) and such large volume use is supplied through separate gas distribution piping to the boiler room. Gas pressure not exceeding 15 psig (100 kPa gauge) is permitted for boiler room equipment in excess of 100,000 cubic feet per hour (2830 m 3 /h) provided the gas distribution piping is installed as provided for in Section 404. The use of pressure in excess of 15 psig (100 kPa gauge) shall be permitted for distribution piping provided all of the requirements of Section 406 are met.
Materials used for piping systems shall be new and comply with the requirements of this chapter or shall be approved.
  1. All requirements for installation of gas distribution piping with operating pressures at 1/2 psig (3.5 kPa gauge) or less and above 1/2 psig (3.5 kPa gauge) shall be in accordance with Chapter 4 of this code.
  2. Gas distribution piping operating at a pressure of over 1/2 psig (3.5 kPa gauge) to 3 psig ( 20 kPa gauge) and size 4 inches (102 mm) or larger shall be welded.
  3. All gas distribution piping operating at a pressure above 3 psig (20 kPa gauge) shall be welded.
  4. All welding of gas distribution piping shall be subject to special inspection as set forth in Section 406.
  5. All piping 4 inches and greater operating at pressure exceeding 3 psig (20 kPa gauge) must be butt welded, subject to special inspection and radiographed.
  6. Threaded piping may be used up to 4 inches (102 mm) at pressure no greater than 1/2 psig (3.5 kPa gauge).
Used pipe, fittings, valves and other materials shall not be re-used.
Material not covered by the standards specifications listed herein shall be investigated and tested to determine that it is safe and suitable for the proposed service, and, in addition, shall be recommended for that service by the manufacturer subject to approval by the commissioner.
Metallic pipe shall comply with Sections 403.4.1 through 403.4.4.
Cast-iron pipe shall not be used.
Carbon steel and wrought-iron pipe shall be at least of standard weight and shall comply with one of the following standards:
  1. ASME B 36.10, 10M
  2. ASTM A 53; or
  3. ASTM A 106.
Copper and brass pipe shall not be used.
Aluminum-alloy pipe shall not be used.
Metallic tubing shall not be used.
Plastic pipe, tubing and fittings shall not be used except as provided for in Sections 401.1.1 and 401.1.2.
Pipe and fittings shall be clear and free from cutting burrs and defects in structure or threading, and shall be thoroughly brushed, and chip and scale blown. Defects in pipe and fittings shall not be repaired. Defective pipe and fittings shall be replaced (see Section 406.1.2).
Where in contact with material or atmosphere exerting a corrosive action, metallic piping and fittings coated with a corrosion-resistant material shall be used. External coatings or linings used on piping or components shall not be considered as adding strength.
Metallic pipe and fitting threads shall be taper pipe threads and shall comply with ASME B1.20.1.
Pipe with threads that are stripped, chipped, corroded or otherwise damaged shall not be used. Where a weld opens during the operation of cutting or threading, that portion of the pipe shall not be used.
Field threading of metallic pipe shall be in accordance with Table 403.9.2.
Table 403.9.2
Specifications for Threading Metallic Pipe


Iron Pipe Size
(inches)

Approximate
Length of
Threaded Portion
(inches)

Approximate
Number of Threads
to be Cut










1/2

3/4

10










3/4

3/4

10










1

7/8

10










11/4

1

11










11/2

1

11










2

1

11










21/2

11/2

12










3

11/2

12










4

15/8

13









For SI: 1 inch = 25.4 mm.
Thread (joint) compounds (pipe dope) shall be resistant to the action of liquefied petroleum gas or to any other chemical constituents of the gases to be conducted through the piping. Use of cotton thread (lamp wick) is prohibited.
The type of piping joint used shall be suitable for the pressure-temperature conditions and shall be selected giving consideration to joint tightness and mechanical strength under the service conditions. The joint shall be able to sustain the maximum end force caused by the internal pressure and any additional forces caused by temperature expansion or contraction, vibration, fatigue or the weight of the pipe and its contents.
Pipe joints shall be threaded, flanged, or welded.
Tubing joints shall not be used.
Flared joints shall not be used.
Metallic fittings, including valves, strainers and filters, shall comply with the following:
  1. Threaded fittings in sizes larger than 4 inches (102 mm) shall not be used.
  2. Fittings used with steel or wrought-iron pipe shall be steel or malleable iron.
  3. Cast-iron fittings:
  3.1. Flanges shall be permitted.
  3.2. Bushings shall not be used.
All flanges shall comply with ASME B16.1, ASME B16.20, AWWA C111/A21.11 or MSS SP-6. The pressure-temperature ratings shall equal or exceed that required by the application.
Standard facings shall be permitted for use under this code. Where 150-pound (1034 kPa) pressure-rated steel flanges are bolted to Class 125 cast-iron flanges, the raised face on the steel flange shall be removed.
Material for gaskets shall be capable of withstanding the design temperature and pressure of the piping system, and the chemical constituents of the gas being conducted, without change to its chemical and physical properties. The effects of fire exposure to the joint shall be considered in choosing material. Acceptable materials include metal or non-asbestos fiber and aluminum "O" rings and spiral wound metal gaskets. When a flanged joint is opened, the gasket shall be replaced. Full-face gaskets shall be used with all cast-iron flanges.
Piping shall not be installed in or through a circulating air duct, trash or clothes chute, chimney or gas vent, ventilating duct, dumbwaiter or elevator shaft. Piping, fixtures, or equipment shall be located so as not to interfere with the normal operation of windows or doors and other exit openings. The following installation limitations shall apply:
  1. Stair enclosures. Gas piping shall not be installed within a stair enclosure or required exit or exit way.
  2. Fire standpipe riser. Gas piping shall not be installed in any shaft containing standpipe risers.
  3. Fire pump. Gas piping or gas consumption devices or any other gas equipment shall not be installed within any space housing a fire pump.
  4. Fire rated construction. Gas piping shall not be installed within concealed spaces of fire-rated construction.
  5. Public corridor. Gas piping shall not be installed in public corridors providing access to required exits.
Concealed piping shall not be located in solid partitions and solid walls, unless installed in a chase or casing.
Portions of a piping system installed in concealed locations shall not have unions, tubing fittings, bushings, compression couplings or swing joints made by combinations of fittings.
Underground piping, where installed below grade through the outer foundation or basement wall of a building, shall be encased in a protective pipe sleeve. The annular space between the gas piping and the sleeve shall be sealed.
Branches shall be taken off the riser with not less than a two-elbow swing.
Piping in solid floors shall be laid in channels in the floor and covered in a manner that will allow access to the piping with a minimum amount of damage to the building. Where such piping is subject to exposure to excessive moisture or corrosive substances, the piping shall be protected in an approved manner. As an alternative to installation in channels, the piping shall be installed in a casing of Schedule 40 steel or wrought iron pipe with tightly sealed ends and joints. At least one end shall have a vented outlet piped to a safe location outdoors. The vent terminal shall be outdoors, minimum 18 inches (457 mm) above grade, not under an opening to building or overhang, and shall be installed so as to prevent the entrance of water and insects. Both ends of such casing shall extend not less than 2 inches (51 mm) beyond the point where the pipe emerges from the floor.
All piping installed outdoors shall be elevated not less than 3 1 / 2 inches (152 mm) above ground and where installed across roof surfaces, shall be elevated not less than 3 1 / 2 inches (152 mm) above the roof surface. Piping installed above ground, outdoors, and installed across the surface of roofs shall be securely supported to the structure and located where it will be protected from physical damage. Where passing through an outside wall, the piping shall also be protected against corrosion by coating or wrapping with an inert material. Where piping is encased in a protective pipe sleeve, the annular space between the piping and the sleeve shall be sealed. At least one end shall have a vented outlet piped to safe location outdoors. The vent terminal shall be outdoors, minimum 18 inches (457 mm) above grade, not under an opening to building or overhang, and shall be installed so as to prevent the entrance of water and insects.
Metallic pipe exposed to corrosive action, such as soil condition or moisture, shall be protected in an approved manner. Zinc coatings (galvanizing) shall not be deemed adequate protection for gas piping underground. Ferrous metal exposed in exterior locations shall be protected from corrosion. Zinc coatings (galvanizing) shall be deemed adequate protection for gas piping exposed in exterior locations. Where dissimilar metals are joined underground, an insulating coupling or fitting shall be used. Piping shall not be laid in contact with cinders.
Uncoated threaded or socket-welded joints shall not be used in piping in contact with soil or where internal or external crevice corrosion is known to occur.
Pipe protective coatings and wrappings shall be approved for the application and shall be factory applied.
  Exception: Where installed in accordance with the manufacturer's installation instructions, field application of coatings and wrappings shall be permitted for pipe nipples, fittings and locations where the factory coating or wrapping has been damaged or necessarily removed at joints.
Underground piping systems shall be installed a minimum depth of 24 inches (610 mm) below grade.
The trench shall be graded so that the pipe has a firm, substantially continuous bearing on the bottom of the trench.
Piping installed underground beneath buildings is prohibited except where the piping is encased in a conduit of wrought iron or steel pipe designed to withstand the superimposed loads. Such conduit shall extend into an occupiable portion of the building and, at the point where the conduit terminates in the building, the space between the conduit and the gas piping shall be sealed to prevent the possible entrance of any gas leakage. The conduit shall be designed for the same pressure as the pipe. Such conduit shall extend not less than 4 inches (102 mm) outside the building, and shall be vented. The vent terminal shall be outdoors, minimum 18 inches (457 mm) above grade, not under an opening to building or overhang, and shall be installed so as to prevent the entrance of water and insects. The conduit shall be protected from corrosion in accordance with Section 404.8.
Gas outlets that do not connect to appliances shall be capped gas tight.
  Exception: Listed and labeled flush-mounted-type quick disconnect devices and listed and labeled gas convenience outlets shall be installed in accordance with the manufacturer's installation instructions.
The unthreaded portion of piping outlets shall extend not less than l inch (25 mm) through finished ceilings and walls and where extending through floors or outdoor patios and slabs, shall not be less than 2 inches (51 mm) above them. The outlet fitting or piping shall be securely supported. Outlets shall not be placed behind doors. Outlets shall be located in the room or space where the appliance is installed.
  Exception: Listed and labeled flush-mounted-type quick disconnect devices and listed and labeled gas convenience outlets shall be installed in accordance with the manufacturer's installation instructions.
A device shall not be placed inside the piping or fittings that will reduce the cross-sectional area or otherwise obstruct the free flow of gas.
  Exception: Approved gas filters.
Before any system of piping is put in service or concealed, it shall be tested to ensure that it is gas tight. Testing, inspection and purging of piping systems shall comply with Section 406.
Section added L.L. 33/2007 § 18, eff. July 1, 2008.
Prior to acceptance and initial operation, all piping installations shall be inspected and pressure tested to determine that the materials, design, fabrication, and installation practices comply with the requirements of this code.
Inspection shall consist of visual examination, during or after manufacture, fabrication, assembly, or pressure tests as appropriate. Supplementary types of nondestructive inspection techniques, such as magnetic-particle, radiographic, ultrasonic, etc., shall not be required unless specifically listed herein or in the engineering design.
Welders installing gas piping within buildings at any pressure shall be qualified for all pipe sizes, wall thicknesses and all positions in accordance with ASME Boiler and Pressure Vessel Code, Section IX and requalified on an annual basis. The qualification testing shall be performed by an approved agency, and the inspector shall have a minimum radiography qualification of Level II in accordance with the ASNT, Document No. SNT-TC-1A, Supplement A. Copies of the certified welder qualification reports shall be maintained by the welder and shall be made available to the department upon request.
All welded gas distribution and meter piping main and branch supplies to customer equipment operating in excess of 3 psig (20 kPa gauge) inside buildings shall be welded; and shall be subject to special inspection in accordance with Chapter 17 of the New York City Building Code.
  Radiography shall be performed on all butt welds in gas meter and gas distribution piping operating at pressures exceeding 3 psig (20 kPa gauge) within buildings, in accordance with ASME Boiler and Pressure Vessel Code, Section IX.
In the event repairs or additions are made after the pressure test, the affected piping shall be tested.
Where new branches are installed from the point of delivery to new appliances, only the newly installed branches shall be required to be pressure tested. Connections between the new piping and the existing piping shall be tested with a noncorrosive leak-detecting fluid or other approved leak-detecting methods.
A piping system shall be permitted to be tested as a complete unit or in sections. Under no circumstances shall a valve in a line be used as a bulkhead between gas in one section of the piping system and test medium in an adjacent section, unless two valves are installed in series with a valved "telltale" located between these valves. A valve shall not be subjected to the test pressure unless it can be determined that the valve, including the valve-closing mechanism, is designed to safely withstand the test pressure.
Regulator and valve assemblies fabricated independently of the piping system in which they are to be installed shall be permitted to be tested with inert gas or air at the time of fabrication.
The test medium shall be air, nitrogen, carbon dioxide or an inert gas. Oxygen shall not be used. Fresh water may be used as the test medium only where the required test pressure exceeds 100 psig (689 kPa).
Pipe joints, including welds, shall be left exposed for examination during the test.
  Exception: Covered or concealed pipe end joints that have been previously tested in accordance with this code.
Expansion joints shall be provided with temporary restraints, if required, for the additional thrust load under test.
Equipment that is not to be included in the test shall be either disconnected from the piping or isolated by blanks, blind flanges, or caps. Flanged joints at which blinds are inserted to blank off other equipment during the test shall not be required to be tested.
Where the piping system is connected to equipment or components designed for operating pressures of less than the test pressure, such equipment or equipment components shall be isolated from the piping system by disconnecting them and capping the outlet(s).
Where the piping system is connected to equipment or components designed for operating pressures equal to or greater than the test pressure, such equipment shall be isolated from the piping system by closing the individual equipment shutoff valve(s).
All testing of piping systems shall be done with due regard for the safety of employees and the public during the test. Bulkheads, anchorage, and bracing suitably designed to resist test pressures shall be installed if necessary. Prior to testing, the interior of the pipe shall be purged to flush out all foreign material including weld splatter, dirt, rags, and other debris left inside the pipe during welding operations and piping installation.
Upon completion of the installation of a section of a gas system or of the entire gas system, and before appliances are connected thereto, the completed section or system shall be verified as to materials, and tested and proven tight as follows:
  1. Gas distribution piping shall comply with the following:
  1.1. Distribution pressures up to 1/2 psig (3.5 kPa gauge). The completed piping is to be tested with a non-mercury gauge at a pressure of 3 psig (20 kPa gauge) for a minimum of 30 minutes.
  1.2. Distribution pressures over 1/2 psig (3.5 kPa gauge) through 3 psig (20 kPa gauge). The completed piping is to be tested at 50 psig (340 kPa gauge) for a minimum of 30 minutes.
  1.3. Distribution pressures over 3 psig (20 kPa gauge) through 15 psig (100 kPa gauge). The completed piping is to be tested at 100 psig (689 kPa gauge) for a minimum of 1 hour.
  1.4. Distribution pressures above 15 psig (100 kPa gauge). The completed piping is to be tested to twice the maximum allowable operating pressure, but not less than 100 psig (689 kPa gauge), for a minimum of 1 hour.
  1.5 Where the test pressure exceeds 125 psig (862 kPa gauge), the test pressure shall not exceed a value that produces a hoop stress in the piping greater that 50 percent of the specified minimum yield strength of the pipe.
  2. Meter piping shall be pressure tested in accordance with the requirements of the serving utility. These requirements shall be either the same as those for testing distribution piping in numbered paragraph 1 of this section or, if different, the piping shall be certified by the local utility as being tested in compliance with their requirements.
  3. Notwithstanding the above, all factory applied coated and wrapped pipe shall be pressure tested at a minimum of 90 psig (621 kPa gauge). For testing, the piping shall be filled with air or an inert gas, and the source of pressure shall be isolated before the pressure readings are made. All test duration time periods are to be measured after stabilization of testing medium. Fresh water may be used as the test medium only where the required test pressure exceeds 100 psig (689 kPa gauge).
  1. This section establishes minimum standards for non-mercury gauges to test gas piping, drainage and vent systems.
  2. Each gauge shall meet the following requirements:
  2.1. The gauge shall be manufactured and used in accordance with ASME B 40.100, which incorporates ASME B 40.1 and ASME B 40.7, and the manufacturer shall provide with the gauge a written statement that the gauge is manufactured in accordance with such ASME standard;
  2.2. The gauge shall be labeled with the name of the manufacturer;
  2.3. The gauge shall be kept in a padded separate rigid box and the manufacturer's instructions for use and protection of the gauge shall be complied with;
  2.4. The units of measurement "psig" shall appear on the face of the gauge; and
  2.5. The gauge shall be kept in good working order.
Each analog gauge used to measure pressure in the magnitude of 3 psig (20 kPa gauge) shall meet the following requirements in addition to satisfying the minimum requirements set forth in section 406.4.1:
  1. The face of the gauge shall not be smaller than 21/4 inches (57 mm) in diameter;
  2. The gauge shall have a minimum of 270° dial arc;
  3. The gauge shall be calibrated in increments of not greater than one-tenth of a pound;
  4. The range of the gauge shall not exceed 5 psig (34.5 kPa gauge) when a 21/4 inch (57 mm) diameter gauge is used;
  5. The 1/10 psig (.69 kPa gauge) interval on the gauge shall not be smaller than 1/10 of an inch ( 2.5 mm) of arc;
  6. The gauge shall be provided with an effective stop for the indicating pointer at the zero point;
  7. The gauge shall be protected from excessive pressure with a shut off valve and prior to using the 5 psig ( 34.5 kPa gauge) the snifter valve shall be tested with a tire gauge to determine the magnitude of pressure; and
  8. The gauge shall have a calibration screw.
Each analog gauge used to measure pressure in the magnitude of 5 psig (34.5 kPa gauge) shall meet the following requirements in addition to satisfying the minimum requirements set forth in Section 406.4.1:
  1. The face of the gauge shall not be smaller than 21/4 inches (57 mm) in diameter;
  2. The gauge shall have a minimum of 270° dial arc;
  3. The gauge shall be calibrated in increments not greater than one-fifth of a pound;
  4. The range of the gauge shall not exceed 10 psig (69 kPa gauge) when a 21/4 inch (57 mm) diameter gauge is used;
  5. The 1/5 interval on the gauge shall not be smaller than 1/10 of an inch (2.5 mm) of arc;
  6. The gauge shall be provided with an effective stop for the indicating pointer at the zero point;
  7. The gauge shall be protected from excessive pressure with a shut-off valve and prior to using the 10 psig (69 kPa gauge) the snifter valve shall be tested with a tire gauge to determine the magnitude of pressure; and
  8. The gauge shall have a calibration screw.
Each digital gauge used to measure pressure in the magnitude of 3 psig (20 kPa gauge) and higher shall meet the following requirements in addition to satisfying the minimum requirements set forth in Section 406.4.1:
  1. The gauge shall have a minimum reading of 1/100 of a psig (69 Pa), and
  2. An extra charged battery shall be readily available for immediate use with the gauge.
Tests of gas piping systems in accordance with this code shall be witnessed by department plumbing inspectors, or approved agencies. The department shall prescribe qualifications for individuals who are authorized to witness such tests on behalf of approved agencies, including but not limited to the requirement that such individuals shall be licensed master plumbers or registered design professionals with not less than five years experience in the inspection and testing of gas piping systems. Such tests may be conducted without any verifying inspection of tests by the department, provided that verified statements and supporting inspectorial and test reports are filed with the department within one working day of such tests.
The holder of the plumbing permit shall give at least two days prior written notice to the commissioner that the plumbing work covered by the permit is ready for inspections and test.
The piping system shall withstand the test pressure specified without showing any evidence of leakage or other defects. Any reduction of test pressures as indicated by pressure gauges shall be deemed to indicate the presence of a leak unless such reduction can be readily attributed to some other cause.
The leakage shall be located by means of an approved gas detector, a noncorrosive leak detection fluid, or other approved leak detection methods. Matches, candles, open flames, or other methods that could provide a source of ignition shall not be used.
Where leakage or other defects are located, the affected portion of the piping system shall be repaired or replaced and retested.
Leakage testing of systems and equipment shall be in accordance with Sections 406.6.1 through 406.6.4.
Leak checks using fuel gas shall be permitted in piping systems that have been pressure tested in accordance with Section 406.
Before gas is introduced into a system of new gas piping, the entire system shall be inspected to determine that there are no open fittings or ends and that all valves at unused outlets are closed and plugged or capped.
It shall be unlawful for any utility company to supply gas to a building, place or premises in which new meters other than replacement are required until a certificate of approval of gas installation from the department is filed with such utility company. When new gas service piping has been installed it shall be locked-off by the utility either by locking the gas service line valve or by installing a locking device on the outside gas service line valve. The lock shall not be removed until the gas meter piping (other than utility-owned) and gas distribution piping has been inspected and certified as required by the department as being ready for service.
When alterations, extensions or repairs to existing gas meter piping or gas distribution piping requires the shut-off of gas flow to a building, the utility shall be notified by the owner or his or her authorized representative.
Immediately after the gas is turned on into a new system or into a system that has been initially restored after an interruption of service, the piping system shall be tested for leakage. Where leakage is indicated, the gas supply shall be shut off until the necessary repairs have been made.
Gas utilization equipment shall be permitted to be placed in operation after the piping system has been tested and determined to be free of leakage and purged in accordance with Section 406.7.2.
The following will be required prior to placing equipment in operation as applicable:
  1. Required fire protections systems (sprinkler or standpipe) are completed, inspected and ready for service.
  2. Such equipment and related gas pipings are inspected by the department or authorized inspector.
  3. Associated fire suppression system is inspected and approved by the Fire Department.
Purging of piping shall comply with Sections 406.7.1 through 406.7.4.
Where gas piping is to be opened for servicing, addition, or modification, the section to be worked on shall be turned off from the gas supply at the nearest convenient point, and the line pressure vented to the outdoors, or to ventilated areas of sufficient size to prevent accumulation of flammable mixtures. The remaining gas in this section of pipe shall be displaced with an inert gas as required by Table 406.7.1.
Table 406.7.1
Length of Piping Requiring Purging With
Inert Gas for Servicing or Modification


Nominal Pipe Size
(inches)

Length of Piping
Requiring Purging








21/2

> 50 feet








3

> 30 feet








4

> 15 feet








6

> 10 feet








8 or larger

Any length







For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
Where piping full of air is placed in operation, the air in the piping shall be displaced with fuel gas, except where such piping is required by Table 406.7.2 to be purged with an inert gas prior to introduction of fuel gas. The air can be safely displaced with fuel gas provided that a moderately rapid and continuous flow of fuel gas is introduced at one end of the line and air is vented out at the other end. The fuel gas flow shall be continued without interruption until the vented gas is free of air. The point of discharge shall not be left unattended during purging. After purging, the vent shall then be closed. Where required by Table 406.7.2, the air in the piping shall first be displaced with an inert gas, and the inert gas shall then be displaced with fuel gas.
Table 406.7.2
Length of Piping Requiring Purging With
Inert Gas Before Placing In Operation


Nominal Pipe Size
(inches)

Length of Piping
Requiring Purging








3

> 30 feet








4

> 15 feet








6

> 10 feet








8 or larger

Any length







For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
The open end of piping systems being purged shall not discharge into confined spaces or areas where there are sources of ignition unless precautions are taken to perform this operation in a safe manner by ventilation of the space, control of purging rate, and elimination of all hazardous conditions.
After the piping has been readied for operation, all equipment shall be purged and then placed in operation, as necessary.
Piping shall be provided with support in accordance with Section 407.2. In addition, when earthquake loads are applicable in accordance with the New York City Building Code, a detailed piping system stress analysis including seismic analysis shall be performed. The pipe supports and restraints shall be designed and installed to accommodate the resultant seismic forces, moments and displacements from this stress analysis in accordance with the New York City Building Code.
Piping shall be supported with pipe hooks, metal pipe straps, bands, brackets, or hangers suitable for the size of piping, of adequate strength and quality, and located at intervals so as to prevent or damp out excessive vibration. Piping shall be anchored to prevent undue strains on connected equipment and shall not be supported by other piping. Pipe hangers and supports shall conform to the requirements of MSS SP-58 and shall be spaced in accordance with Section 415. Supports, hangers, and anchors shall be installed so as not to interfere with the free expansion and contraction of the piping between anchors. All parts of the supporting equipment shall be designed and installed so they will not be disengaged by movement of the supported piping.
Piping for other than dry gas conditions shall be sloped not less than 1 / 4 inch in 15 feet (6.3 mm in 4572 mm) to prevent traps. The local gas supplier/utility company should be consulted to determine the type of fuel gas available for the intended service.
Where the local gas supplier/utility company requires, a manufactured test fitting or drip leg shall be installed downstream of a lockable supply/riser valve in accordance with the requirements for installation of the serving utility. No other locations will be allowed to prevent additional unapproved gas connections.
Where a sediment trap is not incorporated as part of the gas utilization equipment, a sediment trap shall be installed downstream of the equipment shutoff valve as close to the inlet of the equipment as practical. The sediment trap shall be either a tee fitting with a capped nipple in the bottom opening of the run of the tee or other device approved as an effective sediment trap. Illuminating appliances, ranges, clothes dryers and outdoor grills need not be so equipped.
Piping systems shall be provided with shutoff valves in accordance with this section.
Shutoff valves shall be of an approved type. Shutoff valves shall be constructed of materials compatible with the piping. Shutoff valves installed in a portion of a piping system operating above 0.5 psig (3.5 kPa gauge) shall comply with ASME B 16.33. Shutoff valves installed in a portion of a piping system operating at 0.5 psig (3.5 kPa gauge) or less shall comply with ANSI Z 21.15 or ASME B 16.33.
Shutoff valves shall be prohibited in concealed locations and furnace plenums.
Shutoff valves shall be located in places so as to provide access for operation and shall be installed so as to be protected from damage.
Every meter shall be equipped with a shutoff valve located on the supply side of the meter.
Where a single meter is used to supply gas to more than one building or tenant, a separate shutoff valve shall be provided for each building or tenant.
In multiple tenant buildings, where a common piping system is installed to supply other than one- and two-family dwellings, shutoff valves shall be provided for each tenant. Each tenant shall have access to the shutoff valve serving that tenant's space.
In a common system serving more than one building, shutoff valves shall be installed outdoors at each building.
Each house line shutoff valve shall be plainly marked with an identification tag attached by the installer so that the piping systems supplied by such valves are readily identified.
A listed shutoff valve shall be installed immediately ahead of each MP regulator.
Each appliance shall be provided with a shutoff valve separate from the appliance. The shutoff valve shall be located in the same room as the appliance, not further than 6 feet (1829 mm) from the appliance, and shall be installed upstream from the union, connector or quick disconnect device it serves. Such shutoff valves shall be provided with access.
  Exception: Shutoff valves for vented decorative appliances and decorative appliances for installation in vented fireplaces shall not be prohibited from being installed in an area remote from the appliance where such valves are provided with ready access. Such valves shall be permanently identified and shall serve no other equipment. Piping from the shutoff valve to within 3 feet (914 mm) of the appliance connection shall be sized in accordance with Section 402.
Equipment shutoff valves located in the firebox of a fireplace shall be installed in accordance with the appliance manufacturer's instructions.
An outside gas service line valve or other outside shutoff device or method acceptable to the commissioner shall be provided in accordance with Section E.2 of Appendix E of this code.
A line pressure regulator shall be installed where the appliance is designed to operate at a lower pressure than the supply pressure. Access shall be provided to pressure regulators. Pressure regulators shall be protected from physical damage. Regulators installed on the exterior of the building shall be approved for outdoor installation.
MP pressure regulators shall comply with the following:
  1. The MP regulator shall be approved and shall be suitable for the inlet and outlet gas pressures for the application.
  2. The MP regulator shall maintain a reduced outlet pressure under lockup (no-flow) conditions.
  3. The capacity of the MP regulator, determined by published ratings of its manufacturer, shall be adequate to supply the appliances served.
  4. The MP pressure regulator shall be provided with access. Where located indoors, the regulator shall be vented to the outdoors or shall be equipped with a leak-limiting device, in either case complying with Section 410.3.
  5. A tee fitting with one opening capped or plugged shall be installed between the MP regulator and its upstream shutoff valve. Such tee fitting shall be positioned to allow connection of a pressure-measuring instrument and to serve as a sediment trap.
  6. A tee fitting with one opening capped or plugged shall be installed not less than 10 pipe diameters downstream of the MP regulator outlet. Such tee fitting shall be positioned to allow connection of a pressure-measuring instrument.
Pressure regulators that require a vent shall have an independent vent to the outside of the building. The vent shall be designed to prevent the entry of water or foreign objects. The vent terminal shall be outdoors, a minimum of 18 inches (457 mm) above grade, not under an opening to building or overhang, and shall be installed so as to prevent the entrance of water and insects.
  Exception: A vent to the outside of the building is not required for regulators less than 11/4 inches (31.7 mm) NPS equipped with and labeled for utilization with approved vent-limiting devices installed in accordance with the manufacturer's instructions.
Appliances shall be connected to the piping system by one of the following:
  1. Rigid metallic pipe and fittings. Space heaters and water heaters within dwelling units shall be connected using rigid piping and fittings only. Use of semirigid (flexible) metallic tubing, fittings, appliance connectors, or quick-disconnect devices is not permitted for this application.
  2. Semirigid (flexible) metallic tubing and metallic fittings. Lengths shall not exceed 6 feet (1829 mm) and shall be located entirely in the same room as the appliance. Semirigid metallic tubing shall not enter a motor-operated appliance through an unprotected knockout opening.
  3. Listed and labeled appliance connectors installed in accordance with the manufacturer's installation instructions and located entirely in the same room as the appliance.
  4. Listed and labeled quick-disconnect devices used in conjunction with listed and labeled appliance connectors.
  5. Listed and labeled convenience outlets used in conjunction with listed and labeled appliance connectors.
  6. Listed and labeled appliance connectors complying with ANSI Z 21.69 and listed for use with food service equipment having casters, or that is otherwise subject to movement for cleaning, and other large movable equipment.
Connectors and tubing shall be installed so as to be protected against physical damage.
Connectors shall have an overall length not to exceed 3 feet (914 mm), except for range and domestic clothes dryer connectors, which shall not exceed 6 feet (1829 mm) in length. Connectors shall not be concealed within, or extended through, walls, floors, partitions, ceilings or appliance housings. A shutoff valve not less than the nominal size of the connector shall be installed ahead of the connector in accordance with Section 409.5. Connectors shall be sized to provide the total demand of the connected appliance.
  Exception: Fireplace inserts factory equipped with grommets, sleeves, or other means of protection in accordance with the listing of the appliance.
Where appliances are equipped with casters or are otherwise subject to periodic movement or relocation for purposes such as routine cleaning and maintenance, such appliances shall be connected to the supply system piping by means of an approved flexible connector designed and labeled for the application. Such flexible connectors shall be installed and protected against physical damage in accordance with the manufacturer's installation instructions.
Motor fuel-dispensing facilities for LP-gas fuel shall be designed and operated in accordance with the New York City Fire Code.
Motor fuel-dispensing facilities for CNG fuel shall be designed and operated in accordance with the New York City Fire Code.
Section added L.L. 33/2007 § 18, eff. July 1, 2008.
Piping shall be supported at intervals not exceeding the spacing specified in Table 415.1.
Table 415.1
Support of Piping


Steel Pipe,
Nominal Size
of Pipe
(inches)

Spacing of
Supports
(feet)

Nominal Size
of Tubing
(Smooth Wall)
(Inch O.D.)

Spacing of
Supports
(feet)














1/2

6

1/2

4














3/4 or 1

8

5/8 or 3/4

6














11/4 or larger
(horizontal)

10

7/8 or 1
(horizontal)

8














11/4 or larger
(vertical)

Every floor
level

1 or Larger
(vertical)

Every floor
level













For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
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