Adopts With Amendments:

UMC 2021

Heads up: There are no amended sections in this chapter.
CALIFORNIA MECHANICAL CODE — MATRIX ADOPTION TABLE
CHAPTER 13 — FUEL GAS PIPING
(Matrix Adoption Tables are non-regulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)
Adopting Agency BSC BSC-CG SFM HCD DSA OSHPD BSCC DPH AGR DWR CEC CA SL SLC
1
2
1-AC
AC
SS
SS/CC
1
1R
2
3
4
5
Adopt Entire Chapter
X
 
X
X
X
   
X
X
X
X
X
X
X
X
               
Adopt Entire Chapter as
amended (amended sections listed below)
                                             
Adopt only those sections
that are listed below
                                             
Chapter/Section                                              
                                               
This state agency does not adopt sections identified with the following symbol:
The Office of the State Fire Marshal's adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.0.
The regulations of this chapter shall govern the installation of fuel gas piping in or in connection with a building, structure or within the property lines of premises up to 5 pounds-force per square inch (psi) (34 kPa) for natural gas and 10 psi (69 kPa) for undiluted propane, other than service pipe. Fuel oil piping systems shall be installed in accordance with NFPA 31.
Coverage of piping systems shall extend from the point of delivery to the appliance connections. For other than undiluted liquefied petroleum gas (LP-Gas) systems, the point of delivery shall be the outlet of the service meter assembly or the outlet of the service regulator or service shutoff valve where no meter is provided. For undiluted LP-Gas systems, the point of delivery shall be considered to be the outlet of the final pressure regulator, exclusive of line gas regulators where no meter is installed. Where a meter is installed, the point of delivery shall be the outlet of the meter. [NFPA 54: 1.1.1.1(A)]
Requirements for piping systems shall include design, materials, components, fabrication, assembly, installation, testing, inspection, operation, and maintenance. [NFPA 54:1.1.1.1(E)]
This code shall not apply to the following items:
  1. Portable LP-Gas appliances and equipment of all types that are not connected to a fixed fuel piping system.
  2. Installation of appliances such as brooders, dehydrators, dryers, and irrigation equipment used for agricultural purposes.
  3. Raw material (feedstock) applications except for piping to special atmosphere generators.
  4. Oxygen-fuel gas cutting and welding systems.
  5. Industrial gas applications using such gases as acetylene and acetylenic compounds, hydrogen, ammonia, carbon monoxide, oxygen, and nitrogen.
  6. Petroleum refineries, pipeline compressor or pumping stations, loading terminals, compounding plants, refinery tank farms, and natural gas processing plants.
  7. Large integrated chemical plants or portions of such plants where flammable or combustible liquids or gases are produced by chemical reactions or used in chemical reactions.
  8. LP-Gas installations at utility gas plants.
  9. Liquefied natural gas (LNG) installations.
  10. Fuel gas piping in electric utility power plants.
  11. Proprietary items of equipment, apparatus, or instruments such as gas-generating sets, compressors, and calorimeters.
  12. LP-Gas equipment for vaporization, gas mixing, and gas manufacturing.
  13. LP-Gas piping for buildings under construction or renovations that is not to become part of the permanent building piping system-that is, temporary fixed piping for building heat.
  14. Installation of LP-Gas systems for railroad switch heating.
  15. Installation of LP-Gas and compressed natural gas (CNG) systems on vehicles.
  16. Gas piping, meters, gas-pressure regulators, and other appurtenances used by the serving gas supplier in distribution of gas, other than undiluted LP-Gas.
  17. Building design and construction, except as specified herein.
  18. Fuel gas systems on recreational vehicles manufactured in accordance with NFPA 1192.
  19. Fuel gas systems using hydrogen as a fuel.
  20. Construction of appliances. [NFPA 54:1.1.1.2]
Upon completion of the installation, alteration, or repair of gas piping, and prior to the use thereof, the Authority Having Jurisdiction shall be notified that such gas piping is ready for inspection.
Excavations required for the installation of underground piping shall be kept open until such time as the piping has been inspected and approved. Where such piping is covered or concealed before such approval, it shall be exposed upon the direction of the Authority Having Jurisdiction.
The Authority Having Jurisdiction shall make the following inspections and either shall approve that portion of the work as completed or shall notify the permit holder wherein the same fails to be in accordance with this code.
This inspection shall be made after gas piping authorized by the permit has been installed before such piping has been covered or concealed, or before fixture or appliance has been attached thereto. This inspection shall include a determination that the gas piping size, material, and installation meet the requirements of this code.
This inspection shall be made after piping authorized by the permit has been installed and after portions thereof that are to be covered or concealed are so concealed and before fixture, appliance, or shutoff valve has been attached thereto. This inspection shall comply with Section 1313.1. Test gauges used in conducting tests shall be in accordance with Section 1303.3.3 through Section 1303.3.3.4.
Tests required by this code, which are performed utilizing dial gauges, shall be limited to gauges having the following pressure graduations or increments.
Required pressure tests of 10 psi (69 kPa) or less shall be performed with gauges of 0.10 psi (0.69 kPa) increments or less.
Required pressure tests exceeding 10 psi (69 kPa) but less than or equal to 100 psi (689 kPa) shall be performed with gauges of 1 psi (7 kPa) increments or less.
Required pressure tests exceeding 100 psi (689 kPa) shall be performed with gauges of 2 percent increments or less of the required test pressure.
Test gauges shall have a pressure range not exceeding twice the test pressure applied.
In cases where the work authorized by the permit consists of a minor installation of additional piping to piping already connected to a gas meter, the foregoing inspections shall be permitted to be waived at the discretion of the Authority Having Jurisdiction. In this event, the Authority Having Jurisdiction shall make such inspection as deemed advisable in order to be assured that the work has been performed in accordance with the intent of this code.
Where upon final piping inspection, the installation is found to be in accordance with the provisions of this code, a certificate of inspection shall be permitted to be issued by the Authority Having Jurisdiction.
A copy of the certificate of such final piping inspection shall be issued to the serving gas supplier supplying gas to the premises.
It shall be unlawful for a serving gas supplier or person furnishing gas, to turn on or cause to be turned on, fuel gas or a gas meter or meters until such certificate of final inspection, as herein provided, has been issued.
It shall be unlawful for a person, firm, or corporation, excepting an authorized agent or employee of a person, firm, or corporation engaged in the business of furnishing or supplying gas and whose service pipes supply or connect with the particular premises, to turn on or reconnect gas service in or on a premises where gas service is, at the time, not being rendered.
It shall be unlawful to turn on or connect gas in or on the premises unless outlets are securely connected to gas appliances or capped or plugged with screw joint fittings.
The Authority Having Jurisdiction or the serving gas supplier is hereby authorized to disconnect gas piping or appliance or both that shall be found not to be in accordance with the requirements of this code or that are found defective and in such condition as to endanger life or property.
Where such disconnection has been made, a notice shall be attached to such gas piping or appliance or both that shall state the same has been disconnected, together with the reasons thereof.
It shall be unlawful to remove or disconnect gas piping or gas appliance without capping or plugging with a screw joint fitting, the outlet from which said pipe or appliance was removed. Outlets to which gas appliances are not connected shall be left capped and gastight on a piping system that has been installed, altered, or repaired.

Exception: Where an approved listed quick-disconnect device is used.
Where temporary use of gas is desired, and the Authority Having Jurisdiction deems the use necessary, a permit shall be permitted to be issued for such use for a period of time not to exceed that designated by the Authority Having Jurisdiction, provided that such gas piping system otherwise is in accordance with to the requirements of this code regarding material, sizing, and safety.
Where required by the Authority Having Jurisdiction, a piping sketch or plan shall be prepared before proceeding with the installation. The plan shall show the proposed location of piping, the size of different branches, the various load demands, and the location of the point of delivery. [NFPA 54:5.1.1]
When additional appliances are being connected to a gas piping system, the existing piping shall be checked to determine whether it has adequate capacity. If the capacity of the system is determined to be inadequate for the additional appliances, the existing system shall be enlarged as required, or separate gas piping of adequate capacity shall be provided. [NFPA 54:5.1.2]
The location of the point of delivery shall be acceptable to the serving gas supplier. [NFPA 54:5.2]
Where two or more meters, or two or more service regulators where meters are not provided, are located on the same premises and supply separate users, the gas piping systems shall not be interconnected on the outlet side of the meters or service regulators. [NFPA 54:5.3.1]
Where a supplementary gas for standby use is connected downstream from a meter or a service regulator where a meter is not provided, equipment to prevent backflow shall be installed. A three-way valve installed to admit the standby supply and at the same time shut off the regular supply shall be permitted to be used for this purpose. [NFPA 54:5.3.2- 5.3.2.2]
Gas piping systems shall be of such size and so installed as to provide a supply of gas sufficient to meet the maximum demand and supply gas to each appliance inlet at not less than the minimum supply pressure required by the appliance. [NFPA 54:5.4.1]
The volumetric flow rate of gas to be provided shall be the sum of the maximum input of the appliances served. The volumetric flow rate of gas to be provided shall be adjusted for altitude where the installation is above 2000 feet (610 m). [NFPA 54:5.4.2.1 - 5.4.2.2] Where the input rating is not indicated, the gas supplier, appliance manufacturer, or a qualified agency shall be contacted or the rating from Table 1308.4.1 shall be used for estimating the volumetric flow rate of gas to be supplied.

The total connected hourly load shall be used as the basis for piping sizing, assuming all appliances are operating at full capacity simultaneously.

Exception: Sizing shall be permitted to be based upon established load diversity factors. [NFPA 54:5.4.2.3]

TABLE 1308.4.1
APPROXIMATE GAS INPUT FOR TYPICAL APPLIANCES
[NFPA 54: TABLE A.5.4.2.1]
INPUT
(Btu/h approx.)
Space Heating Units  
Warm air furnace  
Single family
100 000
Multifamily, per unit
60 000
Hydronic boiler  
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 storage  
30 to 40 gallon tank
35 000
Water heater, automatic storage  
50 gallon tank
50 000
Water heater, automatic instantaneous  
Capacity at 2 gallons per minute
142 800
Capacity at 4 gallons per minute
285 000
Capacity at 6 gallons per minute
428 400
Water heater, domestic, circulating or side-arm
35 000
Cooking Appliances  
Range, freestanding, domestic
65 000
Built-in oven or broiler unit, domestic
25 000
Built-in top unit, domestic
40 000
Other Appliances  
Refrigerator
3000
Clothes dryer, Type 1 (domestic)
35 000
Gas fireplace direct vent
40 000
Gas log
80 000
Barbecue
40 000
Gaslight
2500
For SI units: 1000 British thermal units per hour = 0.293 kW
Gas piping shall be sized in accordance with one of the following:
  1. Pipe sizing tables or sizing equations in this chapter.
  2. Other approved engineering methods.
  3. Sizing tables included in a listed piping system manufacturer's installation instructions. [NFPA 54:5.4.3]
The design pressure loss in any piping system under maximum probable flow conditions, from the point of delivery to the inlet connection of the appliance, shall be such that the supply pressure at the appliance is greater than or equal to the minimum pressure required by the appliance. [NFPA 54:5.4.4]
Materials used for piping systems shall either comply with the requirements of this chapter or be acceptable to the Authority Having Jurisdiction. [NFPA 54:5.6.1.1]
Pipe, fittings, valves, or other materials shall not be used again unless they are free of foreign materials and have been ascertained to be adequate for the service intended. [NFPA 54:5.6.1.2]
Material not covered by the standards specifications listed herein shall meet the following criteria:
  1. Be investigated and tested to determine that it is safe and suitable for the proposed service.
  2. Be recommended for that service by the manufacturer.
  3. Be acceptable to the Authority Having Jurisdiction. [NFPA 54:5.6.1.3]
Cast-iron pipe shall not be used. [NFPA 54:5.6.2.1]
Steel, stainless steel, and wrought-iron pipe shall be at least Schedule 40 and shall comply with the dimensional standards of ASME B36.10M and one of the following:
  1. ASTM A53
  2. ASTM A106
  3. ASTM A312 {NFPA 54:5.6.2.2}
Copper and copper alloy pipe shall not be used if the gas contains more than an average of 0.3 grains of hydrogen sulfide per 100 standard cubic feet (scf) of gas (0.7 mg/100 L). [NFPA 54:5.6.2.3]

     Threaded copper, copper alloy, or aluminum alloy pipe shall not be used with gases corrosive to such material. [NFPA 54:5.6.2.4]
Aluminum alloy pipe shall comply with ASTM B241 (except that the use of alloy 5456 is prohibited), and shall be marked at each end of each length indicating compliance. Aluminum alloy pipe shall be coated to protect against external corrosion where it is in contact with masonry, plaster, or insulation or is subject to repeated wettings by such liquids as water, detergents, or sewage. [NFPA 54:5.6.2.5]

     Aluminum alloy pipe shall not be used in exterior locations or underground. [NFPA 54:5.6.2.6]
Tubing shall not be used with gases corrosive to the tubing material. [NFPA 54:5.6.3.1]
Stainless steel tubing shall comply with one of the following:
  1. ASTM A268
  2. ASTM A269 [NFPA 54:5.6.3.3]
Steel tubing shall comply with ASTM A254. [NFPA 54:5.6.3.2]
Copper and copper alloy tubing shall not be used if the gas contains more than an average of 0.3 grains of hydrogen sulfide per 100 scf of gas (0.7 mg/100 L). Copper tubing shall comply with standard Type K or L of ASTM B88 or ASTM B280.
Aluminum alloy tubing shall comply with ASTM B210 or ASTM B241. Aluminum alloy tubing shall be coated to protect against external corrosion where it is in contact with masonry, plaster, or insulation or is subject to repeated wettings by such liquids as water, detergent, or sewage. Aluminum alloy tubing shall not be used in exterior locations or underground. [NFPA 54:5.6.3.5]
Corrugated stainless steel tubing shall be listed in accordance with CSA LC-1, [NFPA 54:5.6.3.6]
Polyethylene plastic pipe, tubing, and fittings used to supply fuel gas shall conform to ASTM D2513. Pipe to be used shall be marked "gas" and "ASTM D2513." [NFPA 54:5.6.4.1.1] Polyamide pipe, tubing, and fittings shall be identified in and conform to ASTM F2945, Pipe to be used shall be marked "gas" and "ASTM F2945." [NFPA 54:5.6.4.1.2] Polyvinyl chloride (PVC) and chlorinated polyvinyl chloride (CPVC) plastic pipe, tubing, and fittings shall not be used to supply fuel gas. [NFPA 54:5.6.4.1.3]
Plastic pipe and fittings used to connect regulator vents to remote vent terminations shall be PVC conforming to UL 651. PVC vent piping shall not be installed indoors. [NFPA 54:5.6.4.2]
Anodeless risers shall comply with Section 1308.5.4.2.1 through Section 1308.5.4.2.3. [NFPA 54:5.6.4.3]
Factory-assembled anodeless risers shall be recommended by the manufacturer for the gas used and shall be leak-tested by the manufacturer in accordance with written procedures. [NFPA 54:5.6.4.3(1)]
Service head adapters and field assembled anodeless risers incorporating service head adapters shall be recommended by the manufacturer for the gas used and shall be design-certified to meet the requirements of Category I of ASTM D2513 and 49 CFR 192.281(e). The manufacturer shall provide the user qualified installation instructions as prescribed by 49 CFR 192.283(b). [NFPA 54:5.6.4.3(2)]
The use of plastic pipe, tubing, and fittings in undiluted LP-Gas piping systems shall be in accordance with NFPA 58. [NFPA 54:5.6.4.3(3)]
Gas pipe, tubing, 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, tubing, and fittings shall not be repaired. Defective pipe, tubing, and fittings shall be replaced. [NFPA 54:5.6.5]
Metallic pipe and fitting threads shall be taper pipe threads and shall comply with ASME B1.20.1 [NFPA 54:5.6.6.1]
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. [NFPA 54:5.6.6.2]
Field threading of metallic pipe shall be in accordance with Table 1308.5.6.2. [NFPA 54:5.6.6.3]
TABLE 1308.5.6.2
SPECIFICATIONS FOR THREADING METALLIC PIPE
[NFPA 54: TABLE 5.6.6.3]
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 units: 1 inch = 25.4 mm
Thread joint compounds shall be resistant to the action of LP-Gas or to any other chemical constituents of the gases to be conducted through the piping. [NFPA 54:5.6.6.4]
The type of piping joint used shall be suitable for the pressure and 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 due to the internal pressure and any additional forces due to temperature expansion or contraction, vibration, fatigue, or the weight of the pipe and its contents. [NFPA 54:5.6.7]
Schedule 40 and heavier pipe joints shall be threaded, flanged, brazed, welded, or assembled with press-connect fittings listed to CSA LC 4.
  1. Where nonferrous pipe is brazed, the brazing materials shall have a melting point in excess of 1000°F (538°C).
  2. Brazing alloys shall not contain more than 0.05 percent phosphorus {NFPA 54:5.6.7.1}
Copper tubing joints shall be assembled with approved gas tubing fittings, shall be brazed with a material having a melting point in excess of 1000°F (538°C), or shall be assembled with press-connect fittings listed to CSA LC 4, Press-Connect Metallic Fittings for Use in Fuel Gas Distribution Systems. Brazing alloys shall not contain more than 0.05 percent phosphorus. [NFPA 54:5.6.7.2]
Stainless steel joints shall be welded, assembled with approved tubing fittings, brazed with a material having a melting point in excess of 1000°F (538°C), or assembled with press-connect fittings listed to CSA LC 4, Press-Connect Metallic Fittings for Use in Fuel as Distribution Systems. Brazing alloys and fluxes shall be recommended by the manufacturer for use on stainless steel alloys. [NFPA 54:5.6.7.3]
Flared joints shall be used only in systems constructed from nonferrous pipe and tubing where experience or tests have demonstrated that the joint is suitable for the conditions and where provisions are made in the design to prevent separation of the joints. [NFPA 54:5.6.7.4]
Metallic fittings shall comply with the following:
  1. Threaded fittings in sizes exceeding 4 inches (100 mm) shall not be used.
  2. Fittings used with steel, stainless steel, or wrought-iron pipe shall be steel, stainless steel, copper alloy, malleable iron, or cast-iron.
  3. Fittings used with copper or copper alloy pipe shall be copper or copper alloy.
  4. Fittings used with aluminum alloy pipe shall be aluminum alloy.
  5. Cast-iron fittings shall comply with the following:
    1. Flanges shall be permitted.
    2. Bushings shall not be used.
    3. Fittings shall not be used in systems containing flammable gas-air mixtures.
    4. Fittings in sizes 4 inches (100 mm) and larger shall not be used indoors unless approved by the Authority Having Jurisdiction.
    5. Fittings in sizes 6 inches (150 mm) and larger shall not be used unless approved by the Authority Having Jurisdiction.
  6. Aluminum alloy fitting threads shall not form the joint seal.
  7. Zinc-aluminum alloy fittings shall not be used in systems containing flammable gas-air mixtures.
  8. Special fittings such as couplings; proprietary-type joints; saddle tees; gland-type compression fittings, and flared, flareless, or compression-type tubing fittings shall be as follows:
    1. Used within the fitting manufacturer's pressure-temperature recommendations.
    2. Used within the service conditions anticipated with respect to vibration, fatigue, thermal expansion, or contraction.
    3. Acceptable to the Authority Having Jurisdiction.
  9. When pipe fittings are drilled and tapped in the field, the operation shall be in accordance with the following:
    1. The operation shall be performed on systems having operating pressures of 5 psi (34 kPa) or less.
    2. The operation shall be performed by the gas supplier or their designated representative.
    3. The drilling and tapping operation shall be performed in accordance with written procedures prepared by the gas supplier.
    4. The fittings shall be located outdoors.
    5. The tapped fitting assembly shall be inspected and proven to be free of leaks. [NFPA 54:5.6.7.5]
Plastic pipe, tubing, and fittings shall be joined in accordance with the manufacturer's instructions. Section 1308.5.8.1 through Section 1308.5.8.4 shall be observed where making such joints. [NFPA 54:5.6.8]
The joint shall be designed and installed so that the longitudinal pullout resistance of the joint will be at least equal to the tensile strength of the plastic piping material. [NFPA 54:5.6.8(1)]
Heat fusion joints shall be made in accordance with qualified procedures that have been established and proven by test to produce gastight joints at least as strong as the pipe or tubing being joined. Joints shall be made with the joining method recommended by the pipe manufacturer. Heat-fusion fittings shall be marked "ASTM D2513." [NFPA 54:5.6.8(2)]
Where compression-type mechanical joints are used, the gasket material in the fitting shall be compatible with the plastic piping and with the gas distributed by the system. An internal tubular rigid stiffener shall be used in conjunction with the fitting. The stiffener shall be flush with the end of the pipe or tubing and shall extend at least to the outside end of the compression fitting when installed. The stiffener shall be free of rough or sharp edges and shall not be a force fit in the plastic. Split tubular stiffeners shall not be used. [NFPA 54:5.6.8(3)]
Plastic piping joints and fittings for use in LP-Gas piping systems shall be in accordance with NFPA 58. [NFPA 54:5.6.8(4)]
Cast iron flanges shall be in accordance with ASME B16.1. [NFPA 54:5.6.9.1.1]
Steel flanges shall be in accordance with the following:
  1. ASME B16.5 or
  2. ASME B16.47. [NFPA 54:5.6.10.1.2]
Non-ferrous flanges shall be in accordance with ASME B16.24. [NFPA 54:5.6.9.1.3]
Ductile iron flanges shall be in accordance with ASME B16.42. [NFPA 54:5.6.9.1.4]
Raised-face flanges shall not be joined to flat-faced cast iron, ductile iron or nonferrous material flanges. [NFPA 54:5.6.9.2]
Standard facings shall be permitted for use under this code. Where 150 psi (1034 kPa) steel flanges are bolted to Class 125 cast-iron flanges, the raised face on the steel flange shall be removed. [NFPA 54:5.6.9.3]
Lapped flanges shall be used only aboveground or in exposed locations accessible for inspection. [NFPA 54:5.6.9.4]
The 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 the material. [NFPA 54:5.6.10]
Acceptable materials shall include the following:
  1. Metal (plain or corrugated)
  2. Composition
  3. Aluminum "O" rings
  4. Spiral-wound metal gaskets
  5. Rubber-faced phenolic
  6. Elastomeric [NFPA 54:5.6.10.1]
Metallic flange gaskets shall be in accordance with ASME B16.20. [NFPA 54:5.6.10.2.1]
Non-metallic flange gaskets shall be in accordance with ASME B16.21. [NFPA 54:5.6.10.2.2]
Full-face flange gaskets shall be used with all non-steel flanges. [NFPA 54:5.6.10.3]
When a flanged joint is separated, the gasket shall be replaced. [NFPA 54:5.6.10.4]
Gas meters shall be selected for the maximum expected pressure and permissible pressure drop. [NFPA 54:5.7.1]
Gas meters shall be located in ventilated spaces readily accessible for examination, reading, replacement, or necessary maintenance. [NFPA 54:5.7.2.1]
Gas meters shall not be placed where they will be subjected to damage, such as adjacent to a driveway, under a fire escape, in public passages, halls, or where they will be subject to excessive corrosion or vibration. [NFPA 54:5.7.2.2]
Gas meters shall not be located where they will be subjected to extreme temperatures or sudden extreme changes in temperature or in areas where they are subjected to temperatures beyond those recommended by the manufacturer. [NFPA 54:5.7.2.3]
Gas meters shall be supported or connected to rigid piping so as not to exert a strain on the meters. Where flexible connectors are used to connect a gas meter to downstream piping at mobile homes in mobile home parks, the meter shall be supported by a post or bracket placed in a firm footing or by other means providing equivalent support. [NFPA 54:5.7.3]
Meters shall be protected against overpressure, backpressure, and vacuum. [NFPA 54:5.7.4]
Gas piping at multiple meter installations shall be marked by a metal tag or other permanent means designating the building or the part of the building being supplied and attached by the installing agency. [NFPA 54:5.7.5]
A line pressure regulator shall be installed where the gas supply pressure exceeds the maximum allowable inlet pressure of the appliance served. [NFPA 54:5.8.1]
Line pressure regulators shall be listed in accordance with CSA Z21.80 where the outlet pressure is set to 2 psi (14 kPa) or less. [NFPA 54:5.8.2]
The gas pressure regulator shall be accessible for servicing. [NFPA 54:5.8.3]
Pressure regulators shall be protected against physical damage. [NFPA 54:5.8.4]
Line pressure regulators shall comply with all of the following:
  1. An independent vent to the exterior of the building, sized in accordance with the regulator manufacturer's instructions, shall be provided where the location of a regulator is such that a ruptured diaphragm will cause a hazard.
    1. Where more than one regulator is at a location, each regulator shall have a separate vent to the outdoors or, if approved by the Authority Having Jurisdiction, the vent lines shall be permitted to be manifolded in accordance with accepted engineering practices to minimize backpressure in the event of diaphragm failure.
    2. Materials for vent piping shall be in accordance with Section 1308.5 through Section 1308.5.10.5.
    Exception: A regulator and vent limiting means combination listed as complying with CSA Z21.80 shall be permitted to be used without a vent to the outdoors.
  2. The vent shall be designed to prevent the entry of water, insects, or other foreign materials that could cause blockage.
  3. The regulator vent shall terminate at least 3 feet (914 mm) from a source of ignition.
  4. At locations where regulators might be submerged during floods, a special antiflood-type breather vent fitting shall be installed, or the vent line shall be extended above the height of the expected flood waters.
  5. A regulator shall not be vented to the appliance flue or exhaust system. [NFPA 54:5.8.5.1]
For venting of gas appliance pressure regulators, see Section 902.15. [NFPA 54:5.8.5.2]
Valved and regulated bypasses shall be permitted to be placed around gas line pressure regulators where continuity of service is imperative. [NFPA 54:5.8.6]
Line pressure regulators at multiple regulator installations shall be marked by a metal tag or other permanent means designating the building or the part of the building being supplied. [NFPA 54:5.8.7]
Where the serving gas supplier delivers gas at a pressure greater than 2 psi for piping systems serving appliances designed to operate at a gas pressure of 14 inches water column or less, overpressure protection devices shall be installed. Piping systems serving equipment designed to operate at inlet pressures greater than 14 inches water column (3.5 kPa) shall be equipped with overpressure protection devices as required by the appliance manufacturer's installation instructions. [NFPA 54:5.9.1]
Where piping systems serving appliances designed to operate with a gas supply pressure of 14 inches water column or less are required to be equipped with overpressure protection by Section 1308.8, each overpressure protection device shall be adjusted to limit the gas pressure to each connected appliance to 2 psi or less upon a failure of the line pressure regulator. [NFPA 54:5.9.2.1]
Where piping systems serving appliances designed to operate with a gas supply pressure greater than 14 inches water column are required to be equipped with overpressure protection by Section 1308.8, each overpressure protection device shall be adjusted to limit the gas pressure to each connected appliance as required by the appliance manufacturer's installation instructions. [NFPA 54:5.9.2.2]
Each overpressure protection device installed to meet the requirements of this section shall be capable of limiting the pressure to its connected appliance(s) as required by this section independently of any other pressure control equipment in the piping system. [NFPA 54:5.9.2.3]
Each gas piping system for which an overpressure protection device is required by this section shall be designed and installed so that a failure of the primary pressure control device(s) is detectable. [NFPA 54:5.9.2.4]
If a pressure relief valve is used to meet the requirements of this section, it shall have a flow capacity such that the pressure in the protected system is maintained at or below the limits specified in Section 1308.9 under the following conditions:
  1. The line pressure regulator for which the relief valve is providing overpressure protection has failed wide open.
  2. The gas pressure at the inlet of the line pressure regulator for which the relief valve is providing overpressure protection is not less than the regulator's normal operating inlet pressure. [NFPA 54:5.9.2.5]
Overpressure protection devices shall be one of the following:
  1. Pressure relief valve.
  2. Monitor regulator.
  3. Series regulator installed upstream from the line regulator and set to continuously limit the pressure on the inlet of the line regulator to the maximum values specified by Section 1308.9 or less.
  4. Automatic shutoff device installed in series with the line pressure regulator and set to shut off when the pressure on the downstream piping system reaches the maximum values specified by Section 1308.9 or less. This device shall be designed so that it will remain closed until manually reset. [NFPA 54:5.9.3.1]
The devices in Section 1308.10 shall be installed either as an integral part of the service or line pressure regulator or as separate units. Where separate overpressure protection devices are installed, they shall comply with Section 1308.10.2 through Section 1308.10.7. [NFPA 54:5.9.3.2]
All overpressure protection devices shall meet the following requirements:
  1. Be constructed of materials so that the operation of the device is not impaired by corrosion of external parts by the atmosphere or of internal parts by the gas.
  2. Be designed and installed so they can be operated to determine whether the valve is free. The devices shall also be designed and installed so they can be tested to determine the pressure at which they operate and be examined for leakage when in the closed position. [NFPA 54:5.9.4]
External control piping shall be designed and installed so that damage to the control piping of one device does not render both the regulator and the overpressure protective device inoperative. [NFPA 54:5.9.5]
Each pressure limiting or pressure relieving device shall be set so that the gas pressure supplied to the connected appliance(s) does not exceed the limits specified in Section 1308.9 and Section 1308.9.1. [NFPA 54:5.9.6]
Where unauthorized operation of any shutoff valve could render a pressure relieving valve or pressure limiting device inoperative, one of the following shall be accomplished:
  1. The valve shall be locked in the open position. Instruct authorized personnel in the importance of leaving the shutoff valve open and of being present while the shutoff valve is closed so that it can be locked in the open position before leaving the premises.
  2. Duplicate relief valves shall be installed, each having adequate capacity to protect the system, and arrange the isolating valves or three-way valve so that only one relief valve can be rendered inoperative at a time. [NFPA 54:5.9.7]
The discharge stacks, vents, or outlet parts of all pressure relieving and pressure limiting devices shall be located so that gas is safely discharged to the outdoors. Discharge stacks or vents shall be designed to prevent the entry of water, insects, or other foreign material that could cause blockage. The discharge stack or vent line shall be at least the same size as the outlet of the pressure relieving device. [NFPA 54:5.9.8.1, 5.9.8.2]
The fittings, pipe, and openings located between the system to be protected and the pressure relieving device shall be sized to prevent hammering of the valve and to prevent impairment of relief capacity. [NFPA 54:5.9.9]
Protective devices shall be installed as close to the equipment as practical where the design of equipment connected is such that air, oxygen, or standby gases could be forced into the gas supply system. Gas and air combustion mixers incorporating double diaphragm "zero" or "atmosphere" governors or regulators shall require no further protection unless connected directly to compressed air or oxygen at pressures of 5 psi (34 kPa) or more. [NFPA 54:5.10.1.1, 5.10.1.2]
Protective devices shall include but not be limited to the following:
  1. Check valves.
  2. Three-way valves (of the type that completely closes one side before starting to open the other side).
  3. Reverse flow indicators controlling positive shutoff valves.
  4. Normally closed air-actuated positive shutoff pressure regulators. [NFPA 54:5.10.2]
A protective device shall be installed between the meter and the appliance or equipment if the operation of the appliance or equipment is such that it could produce a vacuum or a dangerous reduction in gas pressure at the meter. Such protective devices include, but are not limited to, mechanical, diaphragm-operated, or electrically operated low-pressure shutoff valves. [NFPA 54:5.11]
Shutoff valves shall be approved and shall be selected giving consideration to pressure drop, service involved, emergency use, and reliability of operation. Shutoff valves of size 1 inch (25 mm) National Pipe Thread and smaller shall be listed. [NFPA 54:5.12]
Piping systems shall be designed to prevent failure from thermal expansion or contraction. [NFPA 54:5.14.1]
Where local conditions include earthquake, tornado, unstable ground, or flood hazards, special consideration shall be given to increased strength and flexibility of piping supports and connections. [NFPA 54:5.14.2]
Where automatic excess flow valves are installed, they shall be listed to CSA Z21.93 and shall be sized and installed in accordance with the manufacturer's instructions. [NFPA 54:5.13]
Underground gas piping shall be installed with sufficient clearance from any other underground structure to avoid contact therewith, to allow maintenance, and to protect against damage from proximity to other structures. In addition, underground plastic piping shall be installed with sufficient clearance or shall be insulated from any source of heat so as to prevent the heat from impairing the serviceability of the pipe. [NFPA 54:7.1.1]
Underground piping systems shall be installed with a minimum of 12 inches (305 mm) of cover. The minimum cover shall be increased to 18 inches (457 mm) if external damage to the pipe or tubing from external forces is likely to result. Where a minimum of 12 inches (305 mm) of cover cannot be provided, the pipe shall be installed in conduit or bridged (shielded). [NFPA 54:7.1.2.1 — 7.1.2.1(B)]
The trench shall be graded so that the pipe has a firm, substantially continuous bearing on the bottom of the trench. [NFPA 54:7.1.2.2]
Where flooding of the trench is done to consolidate the backfill, care shall be exercised to see that the pipe is not floated from its firm bearing on the trench bottom. [NFPA 54:7.1.2.3]
Steel pipe and steel tubing installed underground shall be installed in accordance with Section 1310.1.3.1 through Section 1310.1.3.9. [NFPA 54:7.1.3]
Zinc coating (galvanizing) shall not be deemed adequate protection for underground gas piping. [NFPA 54:7.1.3.1]
Underground piping shall comply with one or more of the following unless approved technical justification is provided to demonstrate that protection is unnecessary:
  1. The piping shall be made of corrosion-resistant material that is suitable for the environment in which it will be installed.
  2. Pipe shall have a factory-applied, electrically insulating coating. Fittings and joints between sections of coated pipe shall be coated in accordance with the coating manufacturer's instructions.
  3. The piping shall have a cathodic protection system installed, and the system shall be maintained in accordance with Section 1310.1.3.3 or Section 1310.1.3.6. [NFPA 54:7.1.3.2]
Cathodic protection systems shall be monitored by testing and the results shall be documented. The test results shall demonstrate one of the following:
  1. A pipe-to-soil voltage of —0.85 volts or more negative is produced, with reference to a saturated copper-copper sulfate half cell.
  2. A pipe-to-soil voltage of —0.78 volts or more negative is produced, with reference to a saturated KCl calomel half cell.
  3. A pipe-to-soil voltage of —0.80 volts or more negative is produced, with reference to a silver-silver chloride half cell.
  4. Compliance with a method described in Appendix D of Title 49 of the Code of Federal Regulations, Part 192. [NFPA 54:7.1.3.3]
Sacrificial anodes shall be tested in accordance with the following:
  1. Upon installation of the cathodic protection system, except where prohibited by climatic conditions, in which case the testing shall be performed not later than 180 days after the installation of the system.
  2. 12 to 18 months after the initial test.
  3. Upon successful verification testing in accordance with Section 1310.1.3.4(1) and Section 1310.1.3.4(2), periodic follow-up testing shall be performed at intervals not to exceed 36 months. [NFPA 54:7.1.3.4]
Systems failing a test shall be repaired not more than 180 days after the date of the failed testing. The testing schedule shall be restarted as required in Section 1310.1.3.4(1) and Section 1310.1.3.4(2), and the results shall comply with Section 1310.1.3.3. [NFPA 54:7.1.3.5]
Impressed current cathodic protection systems shall be inspected and tested in accordance with the following schedule:
  1. The impressed current rectifier voltage output shall be checked at intervals not exceeding two months.
  2. The pipe-to-soil voltage shall be tested at least annually. [NFPA 54:7.1.3.6]
Documentation of the results of the two most recent tests shall be retained. [NFPA 54:7.1.3.7]
Where dissimilar metals are joined underground, an insulating coupling or fitting shall be used. [NFPA 54:7.1.3.8]
Steel risers, other than anodeless risers, connected to plastic piping shall be cathodically protected by means of a welded anode. [NFPA 54:7.1.3.9]
Where the formation of hydrates or ice is known to occur, piping shall be protected against freezing. [NFPA 54:7.1.4]
Underground piping, where installed through the outer foundation or basement wall of a building shall be encased in a protective sleeve or protected by an approved device or method. The space between the gas piping and the sleeve and between the sleeve and the wall shall be sealed to prevent entry of gas and water. [NFPA 54:7.1.5]
Where gas piping is installed underground beneath buildings, the piping shall be either of the following:
  1. Encased in an approved conduit designed to withstand the imposed loads and installed in accordance with Section 1310.1.6.1 or Section 1310.1.6.2.
  2. A piping/encasement system listed for installation beneath buildings. [NFPA 54:7.1.6]
The conduit shall extend into an accessible 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. Where the end sealing is of a type that retains the full pressure of the pipe, the conduit shall be designed for the same pressure as the pipe. The conduit shall extend at least 4 inches (102 mm) outside the building, be vented outdoors above finished ground level, and be installed so as to prevent the entrance of water and insects. [NFPA 54:7.1.6.1]
Where the conduit originates and terminates within the same building, the conduit shall originate and terminate in an accessible portion of the building and shall not be sealed. [NFPA 54:7.1.6.2]
Plastic piping shall be installed outdoors, underground only.

Exceptions:
  1. Plastic piping shall be permitted to terminate aboveground where an anodeless riser is used.
  2. Plastic piping shall be permitted to terminate with a wall head adapter aboveground in buildings, including basements, where the plastic piping is inserted in a piping material permitted for use in buildings. [NFPA 54:7.1.7.1]
Connections made between metallic and plastic piping shall be made with fittings conforming to one of the following:
  1. ASTM D2513 Category I transition fittings
  2. ASTM F1973
  3. ASTM F2509 [NFPA 54:7.1.7.2]
An electrically continuous corrosion-resistant tracer shall be buried with the plastic pipe to facilitate locating. The tracer shall be one of the following:
  1. A product specifically designed for that purpose.
  2. Insulated copper conductor not less than 14 AWG.
     Where tracer wire is used, access shall be provided from aboveground or one end of the tracer wire or tape shall be brought aboveground at a building wall or riser. [NFPA 54:7.1.7.3 - 7.1.7.3.2]
CSST piping systems shall be installed in accordance with this code and the manufacturer's installation instructions. [NFPA 54:7.1.8]
Piping installed aboveground shall be securely supported and located where it will be protected from physical damage. Where passing through an exterior wall, the piping shall also be protected from corrosion by coating or wrapping with an inert material approved for such applications. The piping shall be sealed around its circumference at the point of the exterior penetration to prevent the entry of water, insects, and rodents. Where piping is encased in a protective pipe sleeve, the annular spaces between the gas piping and the sleeve and between the sleeve and the wall opening shall be sealed. [NFPA 54:7.2.1]
Where piping is in contact with a material or an atmosphere corrosive to the piping system, the piping and fittings shall be coated with a corrosion-resistant material. Any such coating used on piping or components shall not be considered as adding strength to the system. [NFPA 54:7.2.2]
The installation of gas piping shall not cause structural stresses within building components to exceed allowable design limits. Approval shall be obtained before any beams or joists are cut or notched. [NFPA 54:7.2.3.1 - 7.2.3.2]
Piping for other than dry gas conditions shall be sloped not less than 1/4 inch in 15 feet (1.4 mm/m) to prevent traps. [NFPA 54:7.2.4]
Gas piping shall be permitted to be installed in accessible spaces between a fixed ceiling and a dropped ceiling, whether or not such spaces are used as a plenum. Valves shall not be located in such spaces.

Exception: Appliance or equipment shutoff valves required by this code shall be permitted to be installed in accessible spaces containing vented appliances.
Gas piping inside any building shall not be installed in or through a clothes chute, chimney or gas vent, dumbwaiter, elevator shaft, or air duct, other than combustion air ducts. [NFPA 54:7.2.5]

Exception: Ducts used to provide ventilation air in accordance with Section 701.0 or to above-ceiling spaces in accordance with Section 1310.3.3.1.
Piping shall be supported with metal pipe hooks, metal pipe straps, metal bands, metal brackets, metal hangers, or building structural components, 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 appliances and equipment and shall not be supported by other piping. Pipe hangers and supports shall conform to the requirements of MSS SP-58. [NFPA 54:7.2.6.1]
Spacing of supports in gas piping installations shall not be greater than shown in Table 1310.3.5.1. Spacing of supports of CSST shall be in accordance with the CSST manufacturer's instructions. [NFPA 54:7.2.6.2]

TABLE 1310.3.5.1
SUPPORT OF PIPING
[NFPA 54: TABLE 7.2.6.2]
STEEL PIPE,
NOMINAL SIZE
OF PIPE
(inches)
SPACING OF
SUPPORTS
(feet)
NOMINAL SIZE
OF TUBING
SMOOTH-WALL
(inches 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 units: 1 inch = 25 mm, 1 foot = 304.8 mm
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 system shall be designed and installed so they are not disengaged by movement of the supported piping. [NFPA 54:7.2.6.3]
Gas piping installed on the roof surfaces shall be elevated above the roof surface and shall be supported in accordance with Table 1310.3.5.1. [NFPA 54:7.2.6.4]
Where piping containing gas is to be removed, the line shall be first disconnected from sources of gas and then thoroughly purged with air, water, or inert gas before cutting or welding is done.
Gas piping in concealed locations shall be installed in accordance with this section. [NFPA 54:7.3.1]
Where gas piping is to be concealed, connections shall be of the following type:
  1. Pipe fittings, such as elbows, tees, couplings, and right/left nipple/couplings.
  2. Joining tubing by brazing (see Section 1308.5.7.1).
  3. Press-connect fittings listed to CSA LC 4.
  4. CSST fittings listed to CSA LC 1.
  5. Where necessary to insert fittings in gas pipe that has been installed in a concealed location, the pipe shall be reconnected by welding, flanges, or the use of a right/left nipple/coupling.
Concealed gas piping shall not be located in solid partitions. [NFPA 54:7.3.3]
This provision shall not apply to tubing that pierces walls, floors, or partitions. Tubing installed vertically and horizontally inside hollow walls or partitions without protection along its entire concealed length shall meet the following requirements:
  1. A steel striker barrier not less than 0.0508 of an inch (1.3 mm) thick, or equivalent, is installed between the tubing and the finished wall and extends at least 4 inches (102 mm) beyond concealed penetrations of plates, firestops, wall studs, and so on.
  2. The tubing is installed in single runs and is not rigidly secured. [NFPA 54:7.3.4]
In industrial occupancies, gas piping in solid floors such as concrete shall be laid in channels in the floor and covered to permit access to the piping with a minimum of damage to the building. Where piping in floor channels could be exposed to excessive moisture or corrosive substances, the piping shall be protected in an approved manner. [NFPA 54:7.3.5.1]

Exception: In other than industrial occupancies and where approved by the Authority Having Jurisdiction, gas piping embedded in concrete floor slabs constructed with Portland cement shall be surrounded with a minimum of 1 1/2 inches (38 mm) of concrete and shall not be in physical contact with other metallic structures such as reinforcing rods or electrically neutral conductors. All piping, fittings, and risers shall be protected against corrosion in accordance with Section 1308.5.6. Piping shall not be embedded in concrete slabs containing quick-set additives or cinder aggregate. [NFPA 54:7.3.5.2]
Where gas piping exceeding 5 psi (34 kPa) is located within vertical chases in accordance with Section 1310.6, the requirements of Section 1310.5.1 through Section 1310.5.3 shall apply. [NFPA 54:7.4]
Where pressure reduction is required in branch connections for compliance with Section 1310.6, such reduction shall take place either inside the chase or immediately adjacent to the outside wall of the chase. Regulator venting and downstream overpressure protection shall comply with Section 1308.7.4, Section 1308.7.5 and Section 1308.8 through Section 1308.10.7. The regulator shall be accessible for service and repair, and vented in accordance with one of the following:
  1. Where the fuel gas is lighter than air, regulators equipped with a vent limiting means shall be permitted to be vented into the chase. Regulators not equipped with a vent limiting means shall be permitted to be vented either directly to the outdoors or to a point within the top 1 foot (305 mm) of the chase.
  2. Where the fuel gas is heavier than air, the regulator vent shall be vented only directly to the outdoors. [NFPA 54:7.4.1]
Chase construction shall comply with local building codes with respect to fire resistance and protection of horizontal and vertical openings. [NFPA 54:7.4.2]
A chase shall be ventilated to the outdoors and only at the top. The opening(s) shall have a minimum free area [in square inches (square meters)] equal to the product of one-half of the maximum pressure in the piping [in pounds per square inch (kilopascals)] times the largest nominal diameter of that piping [in inches (millimeters)], or the cross-sectional area of the chase, whichever is smaller. Where more than one fuel gas piping system is present, the free area for each system shall be calculated and the largest area used. [NFPA 54:7.4.3]
The maximum operating pressure for any piping systems located inside buildings shall not exceed 5 psi (34 kPa) unless one or more of the following conditions are met:
  1. The piping joints are welded or brazed.
  2. The piping joints are flanged and all pipe-to-flange connections are made by welding or brazing.
  3. The piping is located in a ventilated chase or otherwise enclosed for protection against accidental gas accumulation.
  4. The piping is located inside buildings or separate areas of buildings used exclusively for one of the following:
    1. Industrial processing or heating
    2. Research
    3. Warehousing
    4. Boiler or mechanical rooms
  5. The piping is a temporary installation for buildings under construction.
  6. The piping serves appliances or equipment used for agricultural purposes.
  7. The piping system is an LP-Gas piping system with an operating pressure greater than 20 psi (138 kPa) and complies with NFPA 58. [NFPA 54:5.5.4]
LP-Gas systems designed to operate below -5°F (-21°C) or with butane or a propane-butane mix shall be designed to either accommodate liquid LP-Gas or to prevent LP-Gas vapor from condensing back into a liquid. [NFPA 54:5.5.5]
The maximum operating pressure for piping systems serving appliances designed to operate at 14 inches water column (3.5 kPa) inlet pressure or less shall be 2 pounds-force per square inch gauge (psig) (14 kPa) unless an over pressure protection device designed to limit pressure at the appliance to 2 psig (14 kPa) upon failure of the line gas pressure regulator is installed.
Changes in direction of gas pipe shall be made by the use of fittings, factory bends, or field bends. [NFPA 54:7.5]
Metallic pipe bends shall comply with the following:
  1. Bends shall be made only with bending tools and procedures intended for that purpose.
  2. All bends shall be smooth and free from buckling, cracks, or other evidence of mechanical damage.
  3. The longitudinal weld of the pipe shall be near the neutral axis of the bend.
  4. Pipe shall not be bent through an arc of more than 90 degrees.
  5. The inside radius of a bend shall be not less than 6 times the outside diameter of the pipe. [NFPA 54:7.5.1]
Plastic pipe bends shall comply with the following:
  1. The pipe shall not be damaged, and the internal diameter of the pipe shall not be effectively reduced.
  2. Joints shall not be located in pipe bends.
  3. The radius of the inner curve of such bends shall not be less than 25 times the inside diameter of the pipe.
  4. Where the piping manufacturer specifies the use of special bending tools or procedures, such tools or procedures shall be used. [NFPA 54:7.5.2]
Factory-made welding elbows or transverse segments cut therefrom shall have an arc length measured along the crotch of at least 1 inch (25 mm) for pipe sizes 2 inches (50 mm) and larger. [NFPA 54:7.5.3]
For other than dry gas conditions, a drip shall be provided at any point in the line of pipe where condensate could collect. Where required by the Authority Having Jurisdiction or the serving gas supplier, a drip shall also be provided at the outlet of the meter. This drip shall be installed so as to constitute a trap wherein an accumulation of condensate shuts off the flow of gas before it runs back into the meter. [NFPA 54:7.6.1]
All drips shall be installed only in such locations that they are readily accessible to permit cleaning or emptying. A drip shall not be located where the condensate is likely to freeze. [NFPA 54:7.6.2]
The installation of sediment traps shall be in accordance with Section 1312.9. [NFPA 54:7.6.3]
Outlets shall be located and installed in accordance with the following requirements:
  1. The outlet fittings or piping shall be securely fastened in place.
  2. Outlets shall not be located behind doors.
  3. Outlets shall be located far enough from floors, walls, patios, slabs, and ceilings to permit the use of wrenches without straining, bending, or damaging the piping.
  4. The unthreaded portion of gas piping outlets shall extend not less than 1 inch (25.4 mm) through finished ceilings or indoor or outdoor walls.
  5. The unthreaded portion of gas piping outlets shall extend not less than 2 inches (51 mm) above the surface of floors or outdoor patios or slabs.
  6. The provisions of Section 1310.10(4) and Section 1310.10(5) shall not apply to listed quick-disconnect devices of the flush-mounted type or listed gas convenience outlets. Such devices shall be installed in accordance with the manufacturer's installation instructions. [NFPA 54:7.7.1.1 -7.7.1.6]
Each outlet, including a valve, shall be closed gastight with a threaded plug or cap immediately after installation and shall be left closed until the appliance or equipment is connected thereto. When an appliance or equipment is disconnected from an outlet and the outlet is not to be used again immediately, it shall be capped or plugged gastight.

Exceptions:
  1. Laboratory appliances installed in accordance with Section 1312.3.1 shall be permitted.
  2. The use of a listed quick-disconnect device with integral shutoff or listed gas convenience outlet shall be permitted. [NFPA 54:7.7.2.1]
Appliance shutoff valves installed in fireplaces shall be removed and the piping capped gastight where the fireplace is used for solid-fuel burning. [NFPA 54:7.7.2.2]
An accessible gas shutoff valve shall be provided upstream of each gas pressure regulator. Where two gas pressure regulators are installed in series in a single gas line, a manual valve shall not be required at the second regulator. [NFPA 54:7.8.1]
Main gas shutoff valves controlling several gas piping systems shall be readily accessible for operation and installed so as to be protected from physical damage. They shall be marked with a metal tag or other permanent means attached by the installing agency so that the gas piping systems supplied through them can be readily identified. [NFPA 54:7.8.2.1]
In multiple-tenant buildings supplied through a master meter, through one service regulator where a meter is not provided, or where meters or service regulators are not readily accessible from the appliance or equipment location, an individual shutoff valve for each apartment or tenant line shall be provided at a convenient point of general accessibility. In a common system serving a number of individual buildings, shutoff valves shall be installed at each building. [NFPA 54:7.8.2.2]
An exterior shutoff valve to permit turning off the gas supply to each building in an emergency shall be provided. The emergency shutoff valves shall be plainly marked as such and their locations posted as required by the Authority Having Jurisdiction. [NFPA 54:7.8.2.3]
Each laboratory space containing two or more gas outlets installed on tables, benches, or in hoods in educational, research, commercial and industrial occupancies shall have a single shutoff valve through which all such gas outlets are supplied. The shutoff valve shall be accessible, located within the laboratory or adjacent to the laboratory's egress door, and identified. [NFPA 54:7.8.2.4]
Devices shall not be placed within the interior of gas piping or fittings where such devices reduce the cross-sectional area or otherwise obstruct the free flow of gas, except where allowance in the piping system design has been made for such devices. [NFPA 54:7.9]
Where gas-air mixing machines are employed to produce mixtures above or below the flammable range, they shall be provided with stops to prevent adjustment of the mixture to within or approaching the flammable range. [NFPA 54:7.10]
Systems containing flammable gas-air mixtures shall be in accordance with Section 1310.14.1 through Section 1310.14.6.
A central premix system with a flammable mixture in the blower or compressor shall consist of the following components:
  1. Gas-mixing machine in the form of an automatic gas-air proportioning device combined with a downstream blower or compressor.
  2. Flammable mixture piping, minimum Schedule 40.
  3. Automatic firecheck(s).
  4. Safety blowout(s) or backfire preventers for systems utilizing flammable mixture lines above 2 1/2 inches (64 mm) nominal pipe size or the equivalent. [NFPA 54:7.11.1]
The following components shall also be permitted to be utilized in any type of central premix system:
  1. Flowmeter(s)
  2. Flame arrester(s) [NFPA 54:7.11.2]
Gas-mixing machines shall have nonsparking blowers and shall be constructed so that a flashback does not rupture machine casings. [NFPA 54:7.11.3]
A mixing blower system shall be limited to applications with minimum practical lengths of mixture piping, limited to a maximum mixture pressure of 10 inches water column (2.5 kPa) and limited to gases containing no more than 10 percent hydrogen.

     The blower shall be equipped with a gas-control valve at its air entrance arranged so that gas is admitted to the airstream, entering the blower in proper proportions for correct combustion by the type of burners employed, the said gas-control valve being of either the zero governor or mechanical ratio valve type that controls the gas and air adjustment simultaneously. No valves or other obstructions shall be installed between the blower discharge and the burner or burners. [NFPA 54:7.11.4]
Installation of gas-mixing machines shall comply with the following:
  1. The gas-mixing machine shall be located in a well-ventilated area or in a detached building or cutoff room provided with room construction and explosion vents in accordance with sound engineering principles. Such rooms or below-grade installations shall have adequate positive ventilation.
  2. Where gas-mixing machines are installed in well-ventilated areas, the type of electrical equipment shall be in accordance with NFPA 70 for general service conditions unless other hazards in the area prevail. Where gas-mixing machines are installed in small detached buildings or cutoff rooms, the electrical equipment and wiring shall be installed in accordance with NFPA 70 for hazardous locations (Articles 500 and 501, Class I, Division 2).
  3. Air intakes for gas-mixing machines using compressors or blowers shall be taken from outdoors whenever practical.
  4. Controls for gas-mixing machines shall include interlocks and a safety shutoff valve of the manual reset type in the gas supply connection to each machine arranged to automatically shut off the gas supply in the event of high or low gas pressure. Except for open-burner installations only, the controls shall be interlocked so that the blower or compressor stops operating following a gas supply failure. Where a system employs pressurized air, means shall be provided to shut off the gas supply in the event of air failure.
  5. Centrifugal gas-mixing machines in parallel shall be reviewed by the user and equipment manufacturer before installation, and means or plans for minimizing the effects of downstream pulsation and equipment overload shall be prepared and utilized as needed. [NFPA 54:7.11.5.1 - 7.11.5.5]
Automatic firechecks and safety blowouts or backfire preventers shall be provided in piping systems distributing flammable air-gas mixtures from gas-mixing machines to protect the piping and the machines in the event of flashback, in accordance with the following:
  1. Approved automatic firechecks shall be installed upstream as close as practical to the burner inlets following the firecheck manufacturer's instructions.
  2. A separate manually operated gas valve shall be provided at each automatic firecheck for shutting off the flow of the gas-air mixture through the firecheck after a flashback has occurred. The valve shall be located upstream as close as practical to the inlet of the automatic firecheck.

    Caution: These valves shall not be reopened after a flashback has occurred until the firecheck has cooled sufficiently to prevent re-ignition of the flammable mixture and has been reset properly.
  3. A safety blowout or backfiring preventer shall be provided in the mixture line near the outlet of each gas-mixing machine where the size of the piping is larger than 21/2 inches (65 mm) NPS, or equivalent, to protect the mixing equipment in the event of an explosion passing through an automatic firecheck. The manufacturer's instructions shall be followed when installing these devices, particularly after a disc has burst. The discharge from the safety blowout or backfire preventer shall be located or shielded so that particles from the ruptured disc cannot be directed towards personnel. Wherever there are interconnected installations of gas-mixing machines with safety blowouts or backfire preventers, provision shall be made to keep the mixture from other machines from reaching any ruptured disc opening. Check valves shall not be used for this purpose.
  4. Large-capacity premix systems provided with explosion heads (rupture discs) to relieve excessive pressure in pipelines shall be located at and vented to a safe outdoor location. Provisions shall be provided for automatically shutting off the supply of the gas-air mixture in the event of rupture. [NFPA 54:7.11.6]
Each aboveground portion of a gas piping system other than CSST that is likely to become energized shall be electrically continuous and bonded to an effective ground-fault current path. Gas piping, other than CSST, shall be considered to be bonded when it is connected to appliances that are connected to the appliance grounding conductor of the circuit supplying that appliance. [NFPA 54:7.12.1]
CSST gas piping systems, and gas piping systems containing one or more segments of CSST, shall be electrically continuous and bonded to the electrical service grounding electrode system or, where provided, lightning protection grounding electrode system. [NFPA 54:7.12.2]
The bonding jumper shall connect to a metallic pipe, pipe fitting, or CSST fitting. [NFPA 54:7.12.2.1]
The bonding jumper shall not be smaller than 6 AWG copper wire or equivalent. [NFPA 54:7.12.2.2]
The length of the jumper between the connection to the gas piping system and the grounding electrode system shall not exceed 75 feet (22 860 mm). Any additional grounding electrodes installed to meet this requirement shall be bonded to the electrical service grounding electrode system or, where provided, lightning protection grounding electrode system. [NFPA 54:7.12.2.3]
Bonding connections shall be in accordance with NFPA 70. [NFPA 54:7.12.2.4]
Devices used for the bonding connection shall be listed for the application in accordance with UL 467. [NFPA 54:7.12.2.5]
CSST listed with an arc-resistant jacket or coating system in accordance with CSA LC 1 shall be electrically continuous and bonded to an effective ground fault current path. Where any CSST component of a piping system does not have an arc-resistant jacket or coating system, the bonding requirements of Section 1311.2 shall apply. Arc-resistant jacketed CSST shall be considered to be bonded when it is connected to appliances that are connected to the appliance grounding conductor of the circuit supplying that appliance. [NFPA 54:7.12.3]
Gas piping shall not be used as a grounding conductor or electrode. [NFPA 54:7.12.4]
Where a lightning protection system is installed, the bonding of the gas piping shall be in accordance with NFPA 780. [NFPA 54:7.12.5]
Electrical circuits shall not utilize gas piping or components as conductors.

Exception: Low-voltage (50V or less) control circuits, ignition circuits, and electronic flame detection device circuits shall be permitted to make use of piping or components as a part of an electric circuit. [NFPA 54:7.13]
All electrical connections between wiring and electrically operated control devices in a piping system shall conform to the requirements of NFPA 70. [NFPA 54:7.14.1]
Any essential safety control depending on electric current as the operating medium shall be of a type that shuts off (fail safe) the flow of gas in the event of current failure. [NFPA 54:7.14.2]
Appliances and equipment shall be connected to the building piping in compliance with Section 1312.6 through Section 1312.8 by one of the following:
  1. Rigid metallic pipe and fittings.
  2. Semirigid metallic tubing and metallic fittings. Aluminum alloy tubing shall not be used in exterior locations.
  3. A listed connector in compliance with CSA Z21.24. The connector shall be used in accordance with the manufacturer's installation instructions and shall be in the same room as the appliance. Only one connector shall be used per appliance.
  4. A listed connector in compliance with CSA Z21.75. Only one connector shall be used per appliance.
  5. CSST where installed in accordance with the manufacturer's installation instructions. CSST shall connect only to appliances that are fixed in place.
  6. Listed nonmetallic gas hose connectors in accordance with Section 1312.3.
  7. Unlisted gas hose connectors for use in laboratories and educational facilities in accordance with Section 1312.4. [NFPA 54:9.6.1]
Connectors used with commercial cooking appliances that are moved for cleaning and sanitation purposes shall be installed in accordance with the connector manufacturer's installation instructions. Such connectors shall be listed in accordance with CSA Z21.69. [NFPA 54:9.6.1.3]
Movement of appliances with casters shall be limited by a restraining device installed in accordance with the connector and appliance manufacturer's installation instructions. [NFPA 54:9.6.1.4]
Suspended low-intensity infrared tube heaters shall be connected to the building piping system with a connector listed for the application in accordance with CSA Z21.24 as follows:
  1. The connector shall be installed in accordance with the tube heater installation instructions, and shall be in the same room as the appliance.
  2. Only one connector shall be used per appliance. [NFPA 54:9.6.1.5]
Listed gas hose connectors shall be used in accordance with the manufacturer's installation instructions and in accordance with Section 1312.3.1 or Section 1312.3.2. [NFPA 54:9.6.2]
Indoor gas hose connectors shall be used only to connect laboratory, shop, and ironing appliances requiring mobility during operation and installed in accordance with the following:
  1. An appliance shutoff valve shall be installed where the connector is attached to the building piping.
  2. The connector shall be of minimum length and shall not exceed 6 feet (1829 mm).
  3. The connector shall not be concealed and shall not extend from one room to another or pass through wall partitions, ceilings, or floors. [NFPA 54:9.6.2(1)]
Where outdoor gas hose connectors are used to connect portable outdoor appliances, the connector shall be listed in accordance with CSA Z21.54 and installed in accordance with the following:
  1. An appliance shutoff valve, a listed quick-disconnect device, or a listed gas convenience outlet shall be installed where the connector is attached to the supply piping and in such a manner so as to prevent the accumulation of water or foreign matter.
  2. This connection shall be made only in the outdoor area where the appliance is to be used. [NFPA 54:9.6.2(2)]
  3. The connector length shall not exceed 15 feet (4572 mm).
Injection (Bunsen) burners used in laboratories and educational facilities shall be permitted to be connected to the gas supply by an unlisted hose. [NFPA 54:9.6.3]
Where portable industrial appliances or appliances requiring mobility or subject to vibration are connected to the building gas piping system by the use of a flexible hose, the hose shall be suitable and safe for the conditions under which it can be used. [NFPA 54:9.6.4.1]
Where industrial appliances requiring mobility are connected to the rigid piping by the use of swivel joints or couplings, the swivel joints or couplings shall be suitable for the service required and only the minimum number required shall be installed. [NFPA 54:9.6.4.2]
Where industrial appliances subject to vibration are connected to the building piping system by the use of all metal flexible connectors, the connectors shall be suitable for the service required. [NFPA 54:9.6.4.3]
Where flexible connections are used, they shall be of the minimum practical length and shall not extend from one room to another or pass through any walls, partitions, ceilings, or floors. Flexible connections shall not be used in any concealed location. They shall be protected against physical or thermal damage and shall be provided with gas shutoff valves in readily accessible locations in rigid piping upstream from the flexible connections. [NFPA 54:9.6.4.4]
Each appliance connected to a piping system shall have an accessible, approved manual shutoff valve with a nondisplaceable valve member, or a listed gas convenience outlet. Appliance shutoff valves and convenience outlets shall serve a single appliance only. [NFPA 54:9.6.5] The shutoff valve shall be located within 6 feet (1829 mm) of the appliance it serves. [NFPA 54:9.6.5.1] Where a connector is used, the valve shall be installed upstream of the connector. A union or flanged connection shall be provided downstream from the valve to permit removal of appliance controls. [NFPA 54:9.6.5.1(A)]

Exceptions:
  1. Shutoff valves serving decorative appliances in a fireplace shall not be located within the fireplace firebox except where the valve is listed for such use. [NFPA 54:9.6.5.1(B)]
  2. Shutoff valves shall be permitted to be accessibly located inside wall heaters and wall furnaces listed for recessed installation where necessary maintenance is performed without removal of the shutoff valve.
Quick-disconnect devices used to connect appliances to the building piping shall be listed to CSA Z21.41. Where installed indoors, an approved manual shutoff valve with a nondisplaceable valve member shall be installed upstream of the quick-disconnect device. [NFPA 54:9.6.6 - 9.6.6.2]
Appliances shall be permitted to be connected to the building piping by means of a listed gas convenience outlet, in conjunction with a listed appliance connector, installed in accordance with the manufacturer's installation instructions.

     Gas convenience outlets shall be listed in accordance with CSA Z21.90 and installed in accordance with the manufacturer's installation instructions. [NFPA 54:9.6.7]
Where a sediment trap is not incorporated as a part of the appliance, a sediment trap shall be installed downstream of the appliance shutoff valve as close to the inlet of the appliance as practical at the time of appliance installation. The sediment trap shall be either a tee fitting with a capped nipple in the bottom outlet, as illustrated in Figure 1312.9, or another device recognized as an effective sediment trap. Illuminating appliances, gas ranges, clothes dryers, decorative appliances for installation in vented fireplaces, gas fireplaces, and outdoor cooking appliances shall not be required to be so equipped. [NFPA 54:9.6.8]

For SI units: 1 inch = 25.4 mm
FIGURE 1312.9
METHOD OF INSTALLING A TEE FITTING SEDIMENT TRAP
[NFPA 54: FIGURE 9.6.8]
Piping shall be installed in a manner not to interfere with inspection, maintenance, or servicing of the appliances. [NFPA 54:9.6.9]
Prior to acceptance and initial operation, all piping installations shall be visually inspected and pressure tested to determine that the materials, design, fabrication, and installation practices comply with the requirements of this code. [NFPA 54:8.1.1.1]
Inspection shall consist of visual examination, during or after manufacture, fabrication, assembly, or pressure tests. [NFPA 54:8.1.1.2]
Where repairs or additions are made following the pressure test, the affected piping shall be tested. Minor repairs and additions are not required to be pressure tested, provided that the work is inspected and connections are tested with a noncorrosive leak-detecting fluid or other leak-detecting methods approved by the Authority Having Jurisdiction. [NFPA 54:8.1.1.3]
Where new branches are installed to new appliance(s), only the newly installed branch(es) 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 approved leak-detecting methods. [NFPA 54:8.1.1.4]
A piping system shall 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 a double block and bleed valve system is installed. 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 pressure. [NFPA 54:8.1.1.5]
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. [NFPA 54:8.1.1.6]
The test medium shall be air, nitrogen, carbon dioxide, or an inert gas. Oxygen shall not be used as a test medium. [NFPA 54:8.1.2]
Test preparation shall comply with Section 1313.2.1 through Section 1313.2.6.
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. [NFPA 54:8.1.3.1]
Expansion joints shall be provided with temporary restraints, if required, for the additional thrust load under test. [NFPA 54:8.1.3.2]
Appliances and equipment that are 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. [NFPA 54:8.1.3.3]
Where the piping system is connected to appliances or equipment designed for operating pressures of less than the test pressure, such appliances or equipment shall be isolated from the piping system by disconnecting them and capping the outlet(s). [NFPA 54:8.1.3.4]
Where the piping system is connected to appliances or equipment designed for operating pressures equal to or greater than the test pressure, such appliances or equipment shall be isolated from the piping system by closing the individual appliance or equipment shutoff valve(s). [NFPA 54:8.1.3.5]
All testing of piping systems shall be performed in a manner that protects the safety of employees and the public during the test. [NFPA 54:8.1.3.6]
This inspection shall include an air, CO2, or nitrogen pressure test, at which time the gas piping shall stand a pressure of not less than 10 psi (69 kPa) gauge pressure. Test pressures shall be held for a length of time satisfactory to the Authority Having Jurisdiction but in no case less than 15 minutes with no perceptible drop in pressure. For welded piping, and for piping carrying gas at pressures in excess of 14 inches water column (3.5 kPa) pressure, the test pressure shall be not less than 60 psi (414 kPa) and shall be continued for a length of time satisfactory to the Authority Having Jurisdiction, but in no case for less than 30 minutes. For CSST carrying gas at pressures in excess of 14 inches water column (3.5 kPa) pressure, the test pressure shall be 30 psi (207 kPa) for 30 minutes. These tests shall be made using air, CO2, or nitrogen pressure and shall be made in the presence of the Authority Having Jurisdiction. Necessary apparatus for conducting tests shall be furnished by the permit holder. Test gauges used in conducting test shall be in accordance with Section 1303.3.3.1 through Section 1303.3.3.4.
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. [NFPA 54:8.1.5.1]
The leakage shall be located by means of an approved gas detector, a noncorrosive leak detection fluid, or other approved leak detection methods. [NFPA 54:8.1.5.2]
Where leakage or other defects are located, the affected portion of the piping system shall be repaired or replaced and retested. [NFPA 54:8.1.5.3]
Leak checks using fuel gas shall be permitted in piping systems that have been pressure-tested in accordance with Section 1313.0 through Section 1313.4.2. [NFPA 54:8.2.1]
During the process of turning gas on 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. [NFPA 54:8.2.2]
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 checked for leakage. Where leakage is indicated, the gas supply shall be shut off until the necessary repairs have been made. [NFPA 54:8.2.3]
Appliances and equipment shall not be placed in operation until after the piping system has been checked for leakage in accordance with Section 1313.5.2, the piping system is purged in accordance with Section 1313.6, and connections to the appliance are checked for leakage. [NFPA 54:8.2.4]
The purging of piping shall be in accordance with Section 1313.6.1 through Section 1313.6.3. [NFPA 54:8.3]
The purging of piping systems shall be in accordance with Section 1313.6.1.1 through Section 1313.6.1.4 where the piping system meets either of the following:
  1. The design operating gas pressure is greater than 2 psig (14 kPag).
  2. The piping being purged contains one or more sections of pipe or tubing meeting the size and length criteria of Table 1313.6.1. [NFPA 54:8.3.1]
TABLE 1313.6.1
SIZE AND LENGTH OF PIPING
[NFPA 54: TABLE 8.3.1]*
NOMINAL PIPING SIZE
(inches)
LENGTH OF PIPING
(feet)
≥ 21/2 < 3
> 50
≥ 3 < 4
> 30
≥ 4 < 6
> 15
≥ 6 < 8
> 10
≥8
Any length
For SI units: 1 inch = 25 mm; 1 = foot 304.8 mm
* CSST EHD size of 62 is equivalent to nominal 2 inches (50 mm) pipe or tubing size.
Where existing gas piping is opened, the section that is opened shall be isolated from the gas supply and the line pressure vented in accordance with Section 1313.6.1.3. Where gas piping meeting the criteria of Table 1313.6.1 is removed from service, the residual fuel gas in the piping shall be displaced with an inert gas. [NFPA 54:8.3.1.1]
Where gas piping containing air and meeting the criteria of Table 1313.6.1 is placed in operation, the air in the piping shall first be displaced with an inert gas. The inert gas shall then be displaced with fuel gas in accordance with Section 1313.6.1.3. [NFPA 54:8.3.1.2]
The open end of a piping system being pressure vented or purged shall discharge directly to an outdoor location. Purging operations shall comply with all of the following requirements:
  1. The point of discharge shall be controlled with a shutoff valve.
  2. The point of discharge shall be located at least 10 feet (3048 mm) from sources of ignition, at least 10 feet (3048 mm) from building openings and at least 25 feet (7620 mm) from mechanical air intake openings.
  3. During discharge, the open point of discharge shall be continuously attended and monitored with a combustible gas indicator that complies with Section 1313.6.1.4.
  4. Purging operations introducing fuel gas shall be stopped when 90 percent fuel gas by volume is detected within the pipe.
  5. Persons not involved in the purging operations shall be evacuated from all areas within 10 feet (3048 mm) of the point of discharge. [NFPA 54:8.3.1.3]
Combustible gas indicators shall be listed and calibrated in accordance with the manufacturer's instructions. Combustible gas indicators shall numerically display a volume scale from 0 percent to 100 percent in 1 percent or smaller increments. [NFPA 54:8.3.1.4]
The purging of piping systems shall be in accordance with the provisions of Section 1313.6.2.1 where the piping system meets both of the following:
  1. The design operating pressure is 2 psig (14 kPag) or less.
  2. The piping being purged is constructed entirely from pipe or tubing not meeting the size and length criteria of Table 1313.6.1.[NFPA 54:8.3.2]
The piping system shall be purged in accordance with one or more of the following:
  1. The piping shall be purged with fuel gas and shall discharge to the outdoors.
  2. The piping shall be purged with fuel gas and shall discharge to the indoors or outdoors through an appliance burner not located in a combustion chamber. Such burner shall be provided with a continuous source of ignition.
  3. The piping shall be purged with fuel gas and shall discharge to the indoors or outdoors through a burner that has a continuous source of ignition and that is designed for such purpose.
  4. The piping shall be purged with fuel gas that is discharged to the indoors or outdoors, and the point of discharge shall be monitored with a listed combustible gas detector in accordance with Section 1313.6.2.2. Purging shall be stopped when fuel gas is detected.
  5. The piping shall be purged by the gas supplier in accordance with written procedures. [NFPA 54:8.3.2.1]
Combustible gas detectors shall be listed and calibrated or tested in accordance with the manufacturer's instructions. Combustible gas detectors shall be capable of indicating the presence of fuel gas. [NFPA 54:8.3.2.2]
After the piping system has been placed in operation, appliances and equipment shall be purged before being placed into operation. [NFPA 54:8.3.3]
The following regulations, shall comply with this section and Section 1315.0, shall be the standard for the installation of gas piping. Natural gas regulations and tables are based on the use of gas having a specific gravity of 0.60 and for undiluted liquefied petroleum gas having a specific gravity of 1.50.

     Where gas of a different specific gravity is to be delivered, the serving gas supplier shall be permitted to be contacted for specific gravity conversion factors to use in sizing piping systems from the pipe sizing tables in this chapter.
The hourly volume of gas required at each piping outlet shall be taken as not less than the maximum hourly rating as specified by the manufacturer of the appliance or appliances to be connected to each such outlet.
Where the gas appliances to be installed have not been definitely specified, Table 1308.4.1 shall be permitted to be used as a reference to estimate requirements of typical appliances. To obtain the cubic feet per hour (m3/h) of gas required, divide the input of the appliances by the average Btu (kW•h) heating value per cubic foot (m3) of the gas. The average Btu (kW•h) per cubic foot (m3) of the gas in the area of the installation shall be permitted to be obtained from the serving gas supplier.
The size of the supply piping outlet for a gas appliance shall be not less than 1/2 of an inch (15 mm).

     The size of a piping outlet for a mobile home shall be not less than 3/4 of an inch (20 mm).
Where the pipe size is to be determined using any of the methods in Section 1315.1.1 through Section 1315.1.3, the diameter of each pipe segment shall be obtained from the pipe sizing tables in Section 1315.2 or from the sizing equations in Section 1315.3. [NFPA 54:6.1]
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. [NFPA 54:6.1.1]

FIGURE 1315.1.1
EXAMPLE ILLUSTRATING USE OF TABLE 1308.4.1 AND TABLE 1315.2(1)

Problem: Determine the required pipe size of each section and outlet of the piping system shown in Figure 1315.1.1. Gas to be used has a specific gravity of 0.60 and 1100 British thermal units (Btu) per cubic foot (0.0114 kW•h/L), delivered at 8 inch water column (1.9 kPa) pressure.


For SI units: 1 foot = 304.8 mm, 1 gallon = 3.785 L, 1000 British thermal units per hour = 0.293 kW, 1 cubic foot per hour = 0.0283 m3/h

Solution:
  1. Maximum gas demand of Outlet A -
    32 cubic feet per hour (0.91 m3/h) (from Table 1308.4.1).

    Maximum gas demand of Outlet B -
    3 cubic feet per hour (0.08 m3/h) (from Table 1308.4.1).

    Maximum gas demand of Outlet C -
    59 cubic feet per hour (1.67 m3/h) (from Table 1308.4.1).

    Maximum gas demand of Outlet D -
    136 cubic feet per hour (3.85 m3/h) [150000 Btu/hour (44 kW)] divided by 1100 Btu per cubic foot (0.0114 kW•h/L)
  2. The length of pipe from the gas meter to the most remote outlet (Outlet A) is 60 feet (18288 mm).
  3. Using the length in feet column row marked 60 feet (18288 mm) in Table 1315.2(1):

    Outlet A, supplying 32 cubic feet per hour (0.91 m3/h), requires 1/2 of an inch (15 mm) pipe.

    Section 1, supplying Outlets A and B, or 35 cubic feet per hour (0.99 m3/h) requires 1/2 of an inch (15 mm) pipe.

    Section 2, supplying Outlets A, B, and C, or 94 cubic feet per hour (2.66 m3/h) requires 3/4 of an inch (20 mm) pipe.

    Section 3, supplying Outlets A, B, C, and D, or 230 cubic feet per hour (6.51 m3/h), requires 1 inch (25 mm) pipe.
  4. Using the column marked 60 feet (18288 mm) in Table 1315.2(1)

    Outlet B supplying 3 cubic feet per hour (0.08 m3/h), requires 1/2 of an inch (15 mm) pipe.

    Outlet C, supplying 59 cubic feet per hour (1.67 m3/h), requires 1/2 of an inch (15 mm) pipe.

    Using the column marked 60 feet (18288 mm) in Table 1315.2(1):

    Outlet D, supplying 136 cubic feet per hour (3.85 m3/h), requires 3/4 of an inch (20 mm) pipe.
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. [NFPA 54:6.1.2]
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. [NFPA 54:6.1.3]
Sizing of piping systems shall be in accordance with Section 1315.2.1 for natural gas piping systems and Section 1315.2.2 for propane piping systems.

TABLE 1315.2(1)
SCHEDULE 40 METALLIC PIPE [NFPA 54: TABLE 6.2.1(b)]1,2
 
GAS:
NATURAL
INLET PRESSURE:
LESS THAN 2 psi
PRESSURE DROP:
0.5 in. w.c.
SPECIFIC GRAVITY:
0.60
 
PIPE SIZE (inch)
NOMINAL:
1/2
3/4
1
11/4
11/2
2
21/2
3
4
5
6
8
10
12
ACTUAL ID:
0.622
0.824
1.049
1.380
1.610
2.067
2.469
3.068
4.026
5.047
6.065
7.981
10.020
11.938
LENGTH
(feet)
CAPACITY IN CUBIC FEET OF GAS PER HOUR
10
172
360
678
1390
2090
4020
6400
11 300
23 100
41 800
67 600
139 000
252 000
399 000
20
118
247
466
957
1430
2760
4400
7780
15 900
28 700
46 500
95 500
173 000
27 5000
30
95
199
374
768
1150
2220
3530
6250
12 700
23 000
37 300
76 700
139 000
220 000
40
81
170
320
657
985
1900
3020
5350
10 900
19 700
31 900
65 600
119 000
189 000
50
72
151
284
583
873
1680
2680
4740
9660
17 500
28 300
58 200
106 000
167 000
60
65
137
257
528
791
1520
2430
4290
8760
15 800
25 600
52 700
95 700
152 000
70
60
126
237
486
728
1400
2230
3950
8050
14 600
23 600
48 500
88 100
139 000
80
56
117
220
452
677
1300
2080
3670
7490
13 600
22 000
45 100
81 900
130 000
90
52
110
207
424
635
1220
1950
3450
7030
12 700
20 600
42 300
76 900
122 000
100
50
104
195
400
600
1160
1840
3260
6640
12 000
19 500
40 000
72 600
115 000
125
44
92
173
355
532
1020
1630
2890
5890
10 600
17 200
35 400
64 300
102 000
150
40
83
157
322
482
928
1480
2610
5330
9650
15 600
32 100
58 300
92 300
175
37
77
144
296
443
854
1360
2410
4910
8880
14 400
29 500
53 600
84 900
200
34
71
134
275
412
794
1270
2240
4560
8260
13 400
27 500
49 900
79 000
250
30
63
119
244
366
704
1120
1980
4050
7320
11 900
24 300
44 200
70 000
300
27
57
108
221
331
638
1020
1800
3670
6630
10 700
22 100
40 100
63 400
350
25
53
99
203
305
587
935
1650
3370
6100
9880
20 300
36 900
58 400
400
23
49
92
189
283
546
870
1540
3140
5680
9190
18 900
34 300
54 300
450
22
46
86
177
266
512
816
1440
2940
5330
8620
17 700
32 200
50 900
500
21
43
82
168
251
484
771
1360
2780
5030
8150
16 700
30 400
48 100
550
20
41
78
159
239
459
732
1290
2640
4780
7740
15 900
28 900
45 700
600
19
39
74
152
228
438
699
1240
2520
4560
7380
15 200
27 500
43 600
650
18
38
71
145
218
420
669
1180
2410
4360
7070
14 500
26 400
41 800
700
17
36
68
140
209
403
643
1140
2320
4190
6790
14 000
25 300
40 100
750
17
35
66
135
202
389
619
1090
2230
4040
6540
13 400
24 400
38 600
800
16
34
63
130
195
375
598
1060
2160
3900
6320
13 000
23 600
37 300
850
16
33
61
126
189
363
579
1020
2090
3780
6110
12 600
22 800
36 100
900
15
32
59
122
183
352
561
992
2020
3660
5930
12 200
22 100
35 000
950
15
31
58
118
178
342
545
963
1960
3550
5760
11 800
21 500
34 000
1000
14
30
56
115
173
333
530
937
1910
3460
5600
11 500
20 900
33 100
1100
14
28
53
109
164
316
503
890
1810
3280
5320
10 900
19 800
31 400
1200
13
27
51
104
156
301
480
849
1730
3130
5070
10 400
18 900
30 000
1300
12
26
49
100
150
289
460
813
1660
3000
4860
9980
18 100
28 700
1400
12
25
47
96
144
277
442
781
1590
2880
4670
9590
17 400
27 600
1500
11
24
45
93
139
267
426
752
1530
2780
4500
9240
16 800
26 600
1600
11
23
44
89
134
258
411
727
1480
2680
4340
8920
16 200
25 600
1700
11
22
42
86
130
250
398
703
1430
2590
4200
8630
15 700
24 800
1800
10
22
41
84
126
242
386
682
1390
2520
4070
8370
15 200
24 100
1900
10
21
40
81
122
235
375
662
1350
2440
3960
8130
14 800
23 400
2000
NA
20
39
79
119
229
364
644
1310
2380
3850
7910
14 400
22 700
For SI units: 1 inch = 25 mm, 1 foot = 304.8 mm, 1 cubic foot per hour = 0.0283 m3/h, 1 pound-force per square inch = 6.8947 kPa, 1 inch water column = 0.249 kPa
Notes:
  1. 1 Table entries are rounded to 3 significant digits.
  2. 2 NA means a flow of less than 10 ft3/h (0.283 m3/h).
TABLE 1315.2(2)
SCHEDULE 40 METALLIC PIPE [NFPA 54: TABLE 6.2.1(c)]*
 
GAS:
NATURAL
INLET PRESSURE:
LESS THAN 2 psi
PRESSURE DROP:
3.0 in. w.c.
SPECIFIC GRAVITY:
0.60
INTENDED USE: INITIAL SUPPLY PRESSURE OF 8.0 IN. W.C. OR GREATER
 
PIPE SIZE (inch)
NOMINAL:
1/2
3/4
1
11/4
11/2
2
21/2
3
4
ACTUAL ID:
0.622
0.824
1.049
1.380
1.610
2.067
2.469
3.068
4.026
LENGTH (feet)
CAPACITY IN CUBIC FEET OF GAS PER HOUR
10
454
949
1790
3670
5500
10 600
16 900
29 800
60 800
20
312
652
1230
2520
3780
7280
11 600
20 500
41 800
30
250
524
986
2030
3030
5840
9310
16 500
33 600
40
214
448
844
1730
2600
5000
7970
14 100
28 700
50
190
397
748
1540
2300
4430
7060
12 500
25 500
60
172
360
678
1390
2090
4020
6400
11 300
23 100
70
158
331
624
1280
1920
3690
5890
10 400
21 200
80
147
308
580
1190
1790
3440
5480
9690
19 800
90
138
289
544
1120
1670
3230
5140
9090
18 500
100
131
273
514
1060
1580
3050
4860
8580
17 500
125
116
242
456
936
1400
2700
4300
7610
15 500
150
105
219
413
848
1270
2450
3900
6890
14 100
175
96
202
380
780
1170
2250
3590
6340
12 900
200
90
188
353
726
1090
2090
3340
5900
12 000
250
80
166
313
643
964
1860
2960
5230
10 700
300
72
151
284
583
873
1680
2680
4740
9660
350
66
139
261
536
803
1550
2470
4360
8890
400
62
129
243
499
747
1440
2290
4050
8270
450
58
121
228
468
701
1350
2150
3800
7760
500
55
114
215
442
662
1280
2030
3590
7330
550
52
109
204
420
629
1210
1930
3410
6960
600
50
104
195
400
600
1160
1840
3260
6640
650
47
99
187
384
575
1110
1760
3120
6360
700
46
95
179
368
552
1060
1690
3000
6110
750
44
92
173
355
532
1020
1630
2890
5890
800
42
89
167
343
514
989
1580
2790
5680
850
41
86
162
332
497
957
1530
2700
5500
900
40
83
157
322
482
928
1480
2610
5330
950
39
81
152
312
468
901
1440
2540
5180
1000
38
79
148
304
455
877
1400
2470
5040
1100
36
75
141
289
432
833
1330
2350
4780
1200
34
71
134
275
412
794
1270
2240
4560
1300
33
68
128
264
395
761
1210
2140
4370
1400
31
65
123
253
379
731
1160
2060
4200
1500
30
63
119
244
366
704
1120
1980
4050
1600
29
61
115
236
353
680
1080
1920
3910
1700
28
59
111
228
342
658
1050
1850
3780
1800
27
57
108
221
331
638
1020
1800
3670
1900
27
56
105
215
322
619
987
1750
3560
2000
26
54
102
209
313
602
960
1700
3460
For SI units: 1 inch = 25 mm, 1 foot = 304.8 mm, 1 cubic foot per hour = 0.0283 m3/h, 1 pound-force per square inch = 6.8947 kPa, 1 inch water column = 0.249 kPa
* Table entries are rounded to 3 significant digits.


TABLE 1315.2(3)
SCHEDULE 40 METALLIC PIPE [NFPA 54: TABLE 6.2.1(d)]*
 
GAS:
NATURAL
INLET PRESSURE:
LESS THAN 2 psi
PRESSURE DROP:
6.0 in. w.c.
SPECIFIC GRAVITY:
0.60
INTENDED USE: INITIAL SUPPLY PRESSURE OF 11.0 IN. W.C. OR GREATER
 
PIPE SIZE (inch)
NOMINAL:
1/2
3/4
1
11/4
11/2
2
21/2
3
4
ACTUAL ID:
0.622
0.824
1.049
1.38
1.61
2.067
2.469
3.068
4.026
LENGTH
(feet)
CAPACITY IN CUBIC FEET OF GAS PER HOUR
10
660
1380
2600
5340
8000
15 400
24 600
43 400
88 500
20
454
949
1790
3670
5500
10 600
16 900
29 800
60 800
30
364
762
1440
2950
4410
8500
13 600
24 000
48 900
40
312
652
1230
2520
3780
7280
11 600
20 500
41 800
50
276
578
1090
2240
3350
6450
10 300
18 200
37 100
60
250
524
986
2030
3030
5840
9310
16 500
33 600
70
230
482
907
1860
2790
5380
8570
15 100
30 900
80
214
448
844
1730
2600
5000
7970
14 100
28 700
90
201
420
792
1630
2440
4690
7480
13 200
27 000
100
190
397
748
1540
2300
4430
7060
12 500
25 500
125
168
352
663
1360
2040
3930
6260
11 100
22 600
150
153
319
601
1230
1850
3560
5670
10 000
20 500
175
140
293
553
1140
1700
3270
5220
9230
18 800
200
131
273
514
1056
1580
3050
4860
8580
17 500
250
116
242
456
936
1400
2700
4300
7610
15 500
300
105
219
413
848
1270
2450
3900
6890
14 100
350
96
202
380
780
1170
2250
3590
6340
12 900
400
90
188
353
726
1090
2090
3340
5900
12 000
450
84
176
332
681
1020
1960
3130
5540
11 300
500
80
166
313
643
964
1860
2960
5230
10 700
550
76
158
297
611
915
1760
2810
4970
10 100
600
72
151
284
583
873
1680
2680
4740
9660
650
69
144
272
558
836
1610
2570
4540
9250
700
66
139
261
536
803
1550
2470
4360
8890
750
64
134
252
516
774
1490
2380
4200
8560
800
62
129
243
499
747
1440
2290
4050
8270
850
60
125
235
483
723
1390
2220
3920
8000
900
58
121
228
468
701
1350
2150
3800
7760
950
56
118
221
454
681
1310
2090
3690
7540
1000
55
114
215
442
662
1280
2030
3590
7330
1100
52
109
204
420
629
1210
1930
3410
6960
1200
50
104
195
400
600
1160
1840
3260
6640
1300
47
99
187
384
575
1110
1760
3120
6360
1400
46
95
179
368
552
1060
1690
3000
6110
1500
44
92
173
355
532
1020
1630
2890
5890
1600
42
89
167
343
514
989
1580
2790
5680
1700
41
86
162
332
497
957
1530
2700
5500
1800
40
83
157
322
482
928
1480
2610
5330
1900
39
81
152
312
468
901
1440
2540
5180
2000
38
79
148
304
455
877
1400
2470
5040
For SI units: 1 inch = 25 mm, 1 foot = 304.8 mm, 1 cubic foot per hour = 0.0283 m3/h, 1 pound-force per square inch = 6.8947 kPa, 1 inch water column = 0.249 kPa
* Table entries are rounded to 3 significant digits.


TABLE 1315.2(4)
SCHEDULE 40 METALLIC PIPE [NFPA 54: TABLE 6.2.1(e)]*
 
GAS:
NATURAL
INLET PRESSURE:
2.0 psi
PRESSURE DROP:
1.0 psi
SPECIFIC GRAVITY:
0.60
 
PIPE SIZE (inch)
NOMINAL:
1/2
3/4
1
11/4
11/2
2
21/2
3
4
ACTUAL ID:
0.622
0.824
1.049
1.380
1.610
2.067
2.469
3.068
4.026
LENGTH
(feet)
CAPACITY IN CUBIC FEET OF GAS PER HOUR
10
1510
3040
5560
11 400
17 100
32 900
52 500
92 800
189 000
20
1070
2150
3930
8070
12 100
23 300
37 100
65 600
134 000
30
869
1760
3210
6590
9880
19 000
30 300
53 600
109 000
40
753
1520
2780
5710
8550
16 500
26 300
46 400
94 700
50
673
1360
2490
5110
7650
14 700
23 500
41 500
84 700
60
615
1240
2270
4660
6980
13 500
21 400
37 900
77 300
70
569
1150
2100
4320
6470
12 500
19 900
35 100
71 600
80
532
1080
1970
4040
6050
11 700
18 600
32 800
67 000
90
502
1010
1850
3810
5700
11 000
17 500
30 900
63 100
100
462
934
1710
3510
5260
10 100
16 100
28 500
58 200
125
414
836
1530
3140
4700
9060
14 400
25 500
52 100
150
372
751
1370
2820
4220
8130
13 000
22 900
46 700
175
344
695
1270
2601
3910
7530
12 000
21 200
43 300
200
318
642
1170
2410
3610
6960
11 100
19 600
40 000
250
279
583
1040
2140
3210
6180
9850
17 400
35 500
300
253
528
945
1940
2910
5600
8920
15 800
32 200
350
232
486
869
1790
2670
5150
8210
14 5000
29 600
400
216
452
809
1660
2490
4790
7640
13 500
27 500
450
203
424
759
1560
2330
4500
7170
12 700
25 800
500
192
401
717
1470
2210
4250
6770
12 000
24 400
550
182
381
681
1400
2090
4030
6430
11 400
23 200
600
174
363
650
1330
2000
3850
6130
10 800
22 100
650
166
348
622
1280
1910
3680
5870
10 400
21 200
700
160
334
598
1230
1840
3540
5640
9970
20 300
750
154
322
576
1180
1770
3410
5440
9610
19 600
800
149
311
556
1140
1710
3290
5250
9280
18 900
850
144
301
538
1100
1650
3190
5080
8980
18 300
900
139
292
522
1070
1600
3090
4930
8710
17 800
950
135
283
507
1040
1560
3000
4780
8460
17 200
1000
132
275
493
1010
1520
2920
4650
8220
16 800
1100
125
262
468
960
1440
2770
4420
7810
15 900
1200
119
250
446
917
1370
2640
4220
7450
15 200
1300
114
239
427
878
1320
2530
4040
7140
14 600
1400
110
230
411
843
1260
2430
3880
6860
14 000
1500
106
221
396
812
1220
2340
3740
6600
13 500
1600
102
214
382
784
1180
2260
3610
6380
13 000
1700
99
207
370
759
1140
2190
3490
6170
12 600
1800
96
200
358
736
1100
2120
3390
5980
12 200
1900
93
195
348
715
1070
2060
3290
5810
11 900
2000
91
189
339
695
1040
2010
3200
5650
11 500
For SI units: 1 inch = 25 mm, 1 foot = 304.8 mm, 1 cubic foot per hour = 0.0283 m3/h, 1 pound-force per square inch = 6.8947 kPa
* Table entries are rounded to 3 significant digits.


TABLE 1315.2(5)
SCHEDULE 40 METALLIC PIPE [NFPA 54: TABLE 6.2.1(f)]*
 
GAS:
NATURAL
INLET PRESSURE:
3.0 psi
PRESSURE DROP:
2.0 psi
SPECIFIC GRAVITY:
0.60
 
PIPE SIZE (inch)
NOMINAL:
1/2
3/4
1
11/4
11/2
2
21/2
3
4
ACTUAL ID:
0.622
0.824
1.049
1.380
1.610
2.067
2.469
3.068
4.026
LENGTH
(feet)
CAPACITY IN CUBIC FEET OF GAS PER HOUR
10
2350
4920
9270
19 000
28 500
54 900
87 500
155 000
316 000
20
1620
3380
6370
13 100
19 600
37 700
60 100
106 000
217 000
30
1300
2720
5110
10 500
15 700
30 300
48 300
85 400
174 000
40
1110
2320
4380
8990
13 500
25 900
41 300
73 100
149 000
50
985
2060
3880
7970
11 900
23 000
36 600
64 800
132 000
60
892
1870
3520
7220
10 800
20 800
33 200
58 700
120 000
70
821
1720
3230
6640
9950
19 200
30 500
54 000
110 000
80
764
1600
3010
6180
9260
17 800
28 400
50 200
102 000
90
717
1500
2820
5800
8680
16 700
26 700
47 100
96 100
100
677
1420
2670
5470
8200
15 800
25 200
44 500
90 800
125
600
1250
2360
4850
7270
14 000
22 300
39 500
80 500
150
544
1140
2140
4400
6590
12 700
20 200
35 700
72 900
175
500
1050
1970
4040
6060
11 700
18 600
32 900
67 100
200
465
973
1830
3760
5640
10 900
17 300
30 600
62 400
250
412
862
1620
3330
5000
9620
15 300
27 100
55 300
300
374
781
1470
3020
4530
8720
13 900
24 600
50 100
350
344
719
1350
2780
4170
8020
12 800
22 600
46 100
400
320
669
1260
2590
3870
7460
11 900
21 000
42 900
450
300
627
1180
2430
3640
7000
11 200
19 700
40 200
500
283
593
1120
2290
3430
6610
10 500
18 600
38 000
550
269
563
1060
2180
3260
6280
10 000
17 700
36 100
600
257
537
1010
2080
3110
5990
9550
16 900
34 400
650
246
514
969
1990
2980
5740
9150
16 200
33 000
700
236
494
931
1910
2860
5510
8790
15 500
31 700
750
228
476
897
1840
2760
5310
8470
15 000
30 500
800
220
460
866
1780
2660
5130
8180
14 500
29 500
850
213
445
838
1720
2580
4960
7910
14 000
28 500
900
206
431
812
1670
2500
4810
7670
13 600
27 700
950
200
419
789
1620
2430
4670
7450
13 200
26 900
1000
195
407
767
1580
2360
4550
7240
12 800
26 100
1100
185
387
729
1500
2240
4320
6890
12 200
24 800
1200
177
369
695
1430
2140
4120
6570
11 600
23 700
1300
169
353
666
1370
2050
3940
6290
11 100
22 700
1400
162
340
640
1310
1970
3790
6040
10 700
21 800
1500
156
327
616
1270
1900
3650
5820
10 300
21 000
1600
151
316
595
1220
1830
3530
5620
10 000
20 300
1700
146
306
576
1180
1770
3410
5440
9610
19 600
1800
142
296
558
1150
1720
3310
5270
9320
19 000
1900
138
288
542
1110
1670
3210
5120
9050
18 400
2000
134
280
527
1080
1620
3120
4980
8800
18 000
For SI units: 1 inch = 25 mm, 1 foot = 304.8 mm, 1 cubic foot per hour = 0.0283 m3/h, 1 pound-force per square inch = 6.8947 kPa
* Table entries are rounded to 3 significant digits.


TABLE 1315.2(6)
SCHEDULE 40 METALLIC PIPE [NFPA 54: TABLE 6.2.1(g)]*
 
GAS:
NATURAL
INLET PRESSURE:
5.0 psi
PRESSURE DROP:
3.5 psi
SPECIFIC GRAVITY:
0.60
 
PIPE SIZE (inch)
NOMINAL:
1/2
3/4
1
11/4
11/2
2
21/2
3
4
ACTUAL ID:
0.622
0.824
1.049
1.380
1.610
2.067
2.469
3.068
4.026
LENGTH
(feet)
CAPACITY IN CUBIC FEET OF GAS PER HOUR
10
3190
6430
11 800
24 200
36 200
69 700
111 000
196 000
401 000
20
2250
4550
8320
17 100
25 600
49 300
78 600
139 000
283 000
30
1840
3720
6790
14 000
20 900
40 300
64 200
113 000
231 000
40
1590
3220
5880
12 100
18 100
34 900
55 600
98 200
200 000
50
1430
2880
5260
10 800
16 200
31 200
49 700
87 900
179 000
60
1300
2630
4800
9860
14 800
28 500
45 400
80 200
164 000
70
1200
2430
4450
9130
13 700
26 400
42 000
74 300
151 000
80
1150
2330
4260
8540
12 800
24 700
39 300
69 500
142 000
90
1060
2150
3920
8050
12 100
23 200
37 000
65 500
134 000
100
979
1980
3620
7430
11 100
21 400
34 200
60 400
123 000
125
876
1770
3240
6640
9950
19 200
30 600
54 000
110 000
150
786
1590
2910
5960
8940
17 200
27 400
48 500
98 900
175
728
1470
2690
5520
8270
15 900
25 400
44 900
91 600
200
673
1360
2490
5100
7650
14 700
23 500
41 500
84 700
250
558
1170
2200
4510
6760
13 000
20 800
36 700
74 900
300
506
1060
1990
4090
6130
11 800
18 800
33 300
67 800
350
465
973
1830
3760
5640
10 900
17 300
30 600
62 400
400
433
905
1710
3500
5250
10 100
16 100
28 500
58 100
450
406
849
1600
3290
4920
9480
15 100
26 700
54 500
500
384
802
1510
3100
4650
8950
14 300
25 200
51 500
550
364
762
1440
2950
4420
8500
13 600
24 000
48 900
600
348
727
1370
2810
4210
8110
12 900
22 900
46 600
650
333
696
1310
2690
4030
7770
12 400
21 900
44 600
700
320
669
1260
2590
3880
7460
11 900
21 000
42 900
750
308
644
1210
2490
3730
7190
11 500
20 300
41 300
800
298
622
1170
2410
3610
6940
11 100
19 600
39 900
850
288
602
1130
2330
3490
6720
10 700
18 900
38 600
900
279
584
1100
2260
3380
6520
10 400
18 400
37 400
950
271
567
1070
2190
3290
6330
10 100
17 800
36 400
1000
264
551
1040
2130
3200
6150
9810
17 300
35 400
1100
250
524
987
2030
3030
5840
9320
16 500
33 600
1200
239
500
941
1930
2900
5580
8890
15 700
32 000
1300
229
478
901
1850
2770
5340
8510
15 000
30 700
1400
220
460
866
1780
2660
5130
8180
14 500
29 500
1500
212
443
834
1710
2570
4940
7880
13 900
28 400
1600
205
428
806
1650
2480
4770
7610
13 400
27 400
1700
198
414
780
1600
2400
4620
7360
13 000
26 500
1800
192
401
756
1550
2330
4480
7140
12 600
25 700
1900
186
390
734
1510
2260
4350
6930
12 300
25 000
2000
181
379
714
1470
2200
4230
6740
11 900
24 300
For SI units: 1 inch = 25 mm, 1 foot = 304.8 mm, 1 cubic foot per hour = 0.0283 m3/h, 1 pound-force per square inch = 6.8947 kPa
* Table entries are rounded to 3 significant digits.


TABLE 1315.2(7)
SEMI-RIGID COPPER TUBING [NFPA 54: TABLE 6.2.1(h)]1, 2
 
GAS:
NATURAL
INLET PRESSURE:
LESS THAN 2 psi
PRESSURE DROP:
0.3 in. w.c.
SPECIFIC GRAVITY:
0.60
 
TUBE SIZE (inch)
NOMINAL:
K & L:
1/4
3/8
1/2
5/8
3/4
1
11/4
11/2
2
ACR:
3/8
1/2
5/8
3/4
7/8
11/8
13/8
OUTSIDE:
0.375
0.500
0.625
0.750
0.875
1.125
1.375
1.625
2.125
INSIDE:3
0.305
0.402
0.527
0.652
0.745
0.995
1.245
1.481
1.959
LENGTH (feet)
CAPACITY IN CUBIC FEET OF GAS PER HOUR
10
20
42
85
148
210
448
806
1270
2650
20
14
29
58
102
144
308
554
873
1820
30
11
23
47
82
116
247
445
701
1460
40
10
20
40
70
99
211
381
600
1250
50
NA
17
35
62
88
187
337
532
1110
60
NA
16
32
56
79
170
306
482
1000
70
NA
14
29
52
73
156
281
443
924
80
NA
13
27
48
68
145
262
413
859
90
NA
13
26
45
64
136
245
387
806
100
NA
12
24
43
60
129
232
366
761
125
NA
11
22
38
53
114
206
324
675
150
NA
10
20
34
48
103
186
294
612
175
NA
NA
18
31
45
95
171
270
563
200
NA
NA
17
29
41
89
159
251
523
250
NA
NA
15
26
37
78
141
223
464
300
NA
NA
13
23
33
71
128
202
420
350
NA
NA
12
22
31
65
118
186
387
400
NA
NA
11
20
28
61
110
173
360
450
NA
NA
11
19
27
57
103
162
338
500
NA
NA
10
18
25
54
97
153
319
550
NA
NA
NA
17
24
51
92
145
303
600
NA
NA
NA
16
23
49
88
139
289
650
NA
NA
NA
15
22
47
84
133
277
700
NA
NA
NA
15
21
45
81
128
266
750
NA
NA
NA
14
20
43
78
123
256
800
NA
NA
NA
14
20
42
75
119
247
850
NA
NA
NA
13
19
40
73
115
239
900
NA
NA
NA
13
18
39
71
111
232
950
NA
NA
NA
13
18
38
69
108
225
1000
NA
NA
NA
12
17
37
67
105
219
1100
NA
NA
NA
12
16
35
63
100
208
1200
NA
NA
NA
11
16
34
60
95
199
1300
NA
NA
NA
11
15
32
58
91
190
1400
NA
NA
NA
10
14
31
56
88
183
1500
NA
NA
NA
NA
14
30
54
84
176
1600
NA
NA
NA
NA
13
29
52
82
170
1700
NA
NA
NA
NA
13
28
50
79
164
1800
NA
NA
NA
NA
13
27
49
77
159
1900
NA
NA
NA
NA
12
26
47
74
155
2000
NA
NA
NA
NA
12
25
46
72
151
For SI units: 1 inch = 25 mm, 1 foot = 304.8 mm, 1 cubic foot per hour = 0.0283 m3/h, 1 pound-force per square inch = 6.8947 kPa, 1 inch water column = 0.249 kPa
Notes:
  1. 1 Table entries are rounded to 3 significant digits.
  2. 2 NA means a flow of less than 10 ft3/h (0.283 m3/h).
  3. 3 Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
TABLE 1315.2(8)
SEMI-RIGID COPPER TUBING [NFPA 54: TABLE 6.2.1(i)]1, 2
 
GAS:
NATURAL
INLET PRESSURE:
LESS THAN 2 psi
PRESSURE DROP:
0.5 in. w.c.
SPECIFIC GRAVITY:
0.60
 
TUBE SIZE (inch)
NOMINAL:
K & L:
1/4
3/8
1/2
5/8
3/4
1
11/4
11/2
2
ACR:
3/8
1/2
5/8
3/4
7/8
11/8
13/8
OUTSIDE:
0.375
0.500
0.625
0.750
0.875
1.125
1.375
1.625
2.125
INSIDE:3
0.305
0.402
0.527
0.652
0.745
0.995
1.245
1.481
1.959
LENGTH (feet)
CAPACITY IN CUBIC FEET OF GAS PER HOUR
10
27
55
111
195
276
590
1060
1680
3490
20
18
38
77
134
190
406
730
1150
2400
30
15
30
61
107
152
326
586
925
1930
40
13
26
53
92
131
279
502
791
1650
50
11
23
47
82
116
247
445
701
1460
60
10
21
42
74
105
224
403
635
1320
70
NA
19
39
68
96
206
371
585
1220
80
NA
18
36
63
90
192
345
544
1130
90
NA
17
34
59
84
180
324
510
1060
100
NA
16
32
56
79
170
306
482
1000
125
NA
14
28
50
70
151
271
427
890
150
NA
13
26
45
64
136
245
387
806
175
NA
12
24
41
59
125
226
356
742
200
NA
11
22
39
55
117
210
331
690
250
NA
NA
20
34
48
103
186
294
612
300
NA
NA
18
31
44
94
169
266
554
350
NA
NA
16
28
40
86
155
245
510
400
NA
NA
15
26
38
80
144
228
474
450
NA
NA
14
25
35
75
135
214
445
500
NA
NA
13
23
33
71
128
202
420
550
NA
NA
13
22
32
68
122
192
399
600
NA
NA
12
21
30
64
116
183
381
650
NA
NA
12
20
29
62
111
175
365
700
NA
NA
11
20
28
59
107
168
350
750
NA
NA
11
19
27
57
103
162
338
800
NA
NA
10
18
26
55
99
156
326
850
NA
NA
10
18
25
53
96
151
315
900
NA
NA
NA
17
24
52
93
147
306
950
NA
NA
NA
17
24
50
90
143
297
1000
NA
NA
NA
16
23
49
88
139
289
1100
NA
NA
NA
15
22
46
84
132
274
1200
NA
NA
NA
15
21
44
80
126
262
1300
NA
NA
NA
14
20
42
76
120
251
1400
NA
NA
NA
13
19
41
73
116
241
1500
NA
NA
NA
13
18
39
71
111
232
1600
NA
NA
NA
13
18
38
68
108
224
1700
NA
NA
NA
12
17
37
66
104
217
1800
NA
NA
NA
12
17
36
64
101
210
1900
NA
NA
NA
11
16
35
62
98
204
2000
NA
NA
NA
11
16
34
60
95
199
For SI units: 1 inch = 25 mm, 1 foot = 304.8 mm, 1 cubic foot per hour = 0.0283 m3/h, 1 pound-force per square inch = 6.8947 kPa, 1 inch water column = 0.249 kPa
Notes:
  1. 1 Table entries are rounded to 3 significant digits.
  2. 2 NA means a flow of less than 10 ft3/h (0.283 m3/h).
  3. 3 Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
TABLE 1315.2(9)
SEMI-RIGID COPPER TUBING [NFPA 54: TABLE 6.2.1(j)]1, 2
 
GAS:
NATURAL
INLET PRESSURE:
LESS THAN 2 psi
PRESSURE DROP:
1.0 in. w.c.
SPECIFIC GRAVITY:
0.60
INTENDED USE: TUBE SIZING BETWEEN HOUSE LINE REGULATOR AND THE APPLIANCE
 
TUBE SIZE (inch)
NOMINAL:
K & L:
1/4
3/8
1/2
5/8
3/4
1
11/4
11/2
2
ACR:
3/8
1/2
5/8
3/4
7/8
11/8
13/8
OUTSIDE:
0.375
0.500
0.625
0.750
0.875
1.125
1.375
1.625
2.125
INSIDE:3
0.305
0.402
0.527
0.652
0.745
0.995
1.245
1.481
1.959
LENGTH (feet)
CAPACITY IN CUBIC FEET OF GAS PER HOUR
10
39
80
162
283
402
859
1550
2440
5080
20
27
55
111
195
276
590
1060
1680
3490
30
21
44
89
156
222
474
853
1350
2800
40
18
38
77
134
190
406
730
1150
2400
50
16
33
68
119
168
359
647
1020
2130
60
15
30
61
107
152
326
586
925
1930
70
13
28
57
99
140
300
539
851
1770
80
13
26
53
92
131
279
502
791
1650
90
12
24
49
86
122
262
471
742
1550
100
11
23
47
82
116
247
445
701
1460
125
NA
20
41
72
103
219
394
622
1290
150
NA
18
37
65
93
198
357
563
1170
175
NA
17
34
60
85
183
329
518
1080
200
NA
16
32
56
79
170
306
482
1000
250
NA
14
28
50
70
151
271
427
890
300
NA
13
26
45
64
136
245
387
806
350
NA
12
24
41
59
125
226
356
742
400
NA
11
22
39
55
117
210
331
690
450
NA
10
21
36
51
110
197
311
647
500
NA
NA
20
34
48
103
186
294
612
550
NA
NA
19
32
46
98
177
279
581
600
NA
NA
18
31
44
94
169
266
554
650
NA
NA
17
30
42
90
162
255
531
700
NA
NA
16
28
40
86
155
245
510
750
NA
NA
16
27
39
83
150
236
491
800
NA
NA
15
26
38
80
144
228
474
850
NA
NA
15
26
36
78
140
220
459
900
NA
NA
14
25
35
75
135
214
445
950
NA
NA
14
24
34
73
132
207
432
1000
NA
NA
13
23
33
71
128
202
420
1100
NA
NA
13
22
32
68
122
192
399
1200
NA
NA
12
21
30
64
116
183
381
1300
NA
NA
12
20
29
62
111
175
365
1400
NA
NA
11
20
28
59
107
168
350
1500
NA
NA
11
19
27
57
103
162
338
1600
NA
NA
10
18
26
55
99
156
326
1700
NA
NA
10
18
25
53
96
151
315
1800
NA
NA
NA
17
24
52
93
147
306
1900
NA
NA
NA
17
24
50
90
143
297
2000
NA
NA
NA
16
23
49
88
139
289
For SI units: 1 inch = 25 mm, 1 foot = 304.8 mm, 1 cubic foot per hour = 0.0283 m3/h, 1 pound-force per square inch = 6.8947 kPa, 1 inch water column = 0.249 kPa
Notes:
  1. 1 Table entries are rounded to 3 significant digits.
  2. 2 NA means a flow of less than 10 ft3/h (0.283 m3/h).
  3. 3 Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
TABLE 1315.2(10)
SEMI-RIGID COPPER TUBING [NFPA 54: TABLE 6.2.1(k)]2
 
GAS:
NATURAL
INLET PRESSURE:
LESS THAN 2 psi
PRESSURE DROP:
17.0 in. w.c.
SPECIFIC GRAVITY:
0.60
 
TUBE SIZE (inch)
NOMINAL:
K & L:
1/4
3/8
1/2
5/8
3/4
1
11/4
11/2
2
ACR:
3/8
1/2
5/8
3/4
7/8
11/8
13/8
OUTSIDE:
0.375
0.500
0.625
0.750
0.875
1.125
1.375
1.625
2.125
INSIDE:1
0.305
0.402
0.527
0.652
0.745
0.995
1.245
1.481
1.959
LENGTH (feet)
CAPACITY IN CUBIC FEET OF GAS PER HOUR
10
190
391
796
1390
1970
4220
7590
12 000
24 900
20
130
269
547
956
1360
2900
5220
8230
17 100
30
105
216
439
768
1090
2330
4190
6610
13 800
40
90
185
376
657
932
1990
3590
5650
11 800
50
79
164
333
582
826
1770
3180
5010
10 400
60
72
148
302
528
749
1600
2880
4540
9460
70
66
137
278
486
689
1470
2650
4180
8700
80
62
127
258
452
641
1370
2460
3890
8090
90
58
119
243
424
601
1280
2310
3650
7590
100
55
113
229
400
568
1210
2180
3440
7170
125
48
100
203
355
503
1080
1940
3050
6360
150
44
90
184
321
456
974
1750
2770
5760
175
40
83
169
296
420
896
1610
2540
5300
200
38
77
157
275
390
834
1500
2370
4930
250
33
69
140
244
346
739
1330
2100
4370
300
30
62
126
221
313
670
1210
1900
3960
350
28
57
116
203
288
616
1110
1750
3640
400
26
53
108
189
268
573
1030
1630
3390
450
24
50
102
177
252
538
968
1530
3180
500
23
47
96
168
238
508
914
1440
3000
550
22
45
91
159
226
482
868
1370
2850
600
21
43
87
152
215
460
829
1310
2720
650
20
41
83
145
206
441
793
1250
2610
700
19
39
80
140
198
423
762
1200
2500
750
18
38
77
135
191
408
734
1160
2410
800
18
37
74
130
184
394
709
1120
2330
850
17
35
72
126
178
381
686
1080
2250
900
17
34
70
122
173
370
665
1050
2180
950
16
33
68
118
168
359
646
1020
2120
1000
16
32
66
115
163
349
628
991
2060
1100
15
31
63
109
155
332
597
941
1960
1200
14
29
60
104
148
316
569
898
1870
1300
14
28
57
100
142
303
545
860
1790
1400
13
27
55
96
136
291
524
826
1720
1500
13
26
53
93
131
280
505
796
1660
1600
12
25
51
89
127
271
487
768
1600
1700
12
24
49
86
123
262
472
744
1550
1800
11
24
48
84
119
254
457
721
1500
1900
11
23
47
81
115
247
444
700
1460
2000
11
22
45
79
112
240
432
681
1420
For SI units: 1 inch = 25 mm, 1 foot = 304.8 mm, 1 cubic foot per hour = 0.0283 m3/h, 1 pound-force per square inch = 6.8947 kPa, 1 inch water column = 0.249 kPa
Notes:
  1. 1 Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
  2. 2 Table entries are rounded to 3 significant digits.
TABLE 1315.2(11)
SEMI-RIGID COPPER TUBING [NFPA 54: TABLE 6.2.1(l)]2
 
GAS:
NATURAL
INLET PRESSURE:
2.0 psi
PRESSURE DROP:
1.0 psi
SPECIFIC GRAVITY:
0.60
 
TUBE SIZE (inch)
NOMINAL:
K & L:
1/4
3/8
1/2
5/8
3/4
1
11/4
11/2
2
ACR:
3/8
1/2
5/8
3/4
7/8
11/8
13/8
OUTSIDE:
0.375
0.500
0.625
0.750
0.875
1.125
1.375
1.625
2.125
INSIDE:1
0.305
0.402
0.527
0.652
0.745
0.995
1.245
1.481
1.959
LENGTH (feet)
CAPACITY IN CUBIC FEET OF GAS PER HOUR
10
245
506
1030
1800
2550
5450
9820
15 500
32 200
20
169
348
708
1240
1760
3750
6750
10 600
22 200
30
135
279
568
993
1410
3010
5420
8550
17 800
40
116
239
486
850
1210
2580
4640
7310
15 200
50
103
212
431
754
1070
2280
4110
6480
13 500
60
93
192
391
683
969
2070
3730
5870
12 200
70
86
177
359
628
891
1900
3430
5400
11 300
80
80
164
334
584
829
1770
3190
5030
10 500
90
75
154
314
548
778
1660
2990
4720
9820
100
71
146
296
518
735
1570
2830
4450
9280
125
63
129
263
459
651
1390
2500
3950
8220
150
57
117
238
416
590
1260
2270
3580
7450
175
52
108
219
383
543
1160
2090
3290
6850
200
49
100
204
356
505
1080
1940
3060
6380
250
43
89
181
315
448
956
1720
2710
5650
300
39
80
164
286
406
866
1560
2460
5120
350
36
74
150
263
373
797
1430
2260
4710
400
33
69
140
245
347
741
1330
2100
4380
450
31
65
131
230
326
696
1250
1970
4110
500
30
61
124
217
308
657
1180
1870
3880
550
28
58
118
206
292
624
1120
1770
3690
600
27
55
112
196
279
595
1070
1690
3520
650
26
53
108
188
267
570
1030
1620
3370
700
25
51
103
181
256
548
986
1550
3240
750
24
49
100
174
247
528
950
1500
3120
800
23
47
96
168
239
510
917
1450
3010
850
22
46
93
163
231
493
888
1400
2920
900
22
44
90
158
224
478
861
1360
2830
950
21
43
88
153
217
464
836
1320
2740
1000
20
42
85
149
211
452
813
1280
2670
1100
19
40
81
142
201
429
772
1220
2540
1200
18
38
77
135
192
409
737
1160
2420
1300
18
36
74
129
183
392
705
1110
2320
1400
17
35
71
124
176
376
678
1070
2230
1500
16
34
68
120
170
363
653
1030
2140
1600
16
33
66
116
164
350
630
994
2070
1700
15
31
64
112
159
339
610
962
2000
1800
15
30
62
108
154
329
592
933
1940
1900
14
30
60
105
149
319
575
906
1890
2000
14
29
59
102
145
310
559
881
1830
For SI units: 1 inch = 25 mm, 1 foot = 304.8 mm, 1 cubic foot per hour = 0.0283 m3/h, 1 pound-force per square inch = 6.8947 kPa
Notes:
  1. 1 Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
  2. 2 Table entries are rounded to 3 significant digits.
TABLE 1315.2(12)
SEMI-RIGID COPPER TUBING [NFPA 54: TABLE 6.2.1(m)]3
 
GAS:
NATURAL
INLET PRESSURE:
2.0 psi
PRESSURE DROP:
1.5 psi
SPECIFIC GRAVITY:
0.60
INTENDED USE: PIPE SIZING BETWEEN POINT OF DELIVERY AND THE HOUSE LINE REGULATOR. TOTAL LOAD SUPPLIED BY A
SINGLE HOUSE LINE REGULATOR NOT EXCEEDING 150 CUBIC FEET PER HOUR2.
 
TUBE SIZE (inch)
NOMINAL:
K & L:
1/4
3/8
1/2
5/8
3/4
1
11/4
11/2
2
ACR:
3/8
1/2
5/8
3/4
7/8
11/8
13/8
OUTSIDE:
0.375
0.500
0.625
0.750
0.875
1.125
1.375
1.625
2.125
INSIDE:1
0.305
0.402
0.527
0.652
0.745
0.995
1.245
1.481
1.959
LENGTH (feet)
CAPACITY IN CUBIC FEET OF GAS PER HOUR
10
303
625
1270
2220
3150
6740
12 100
19 100
39 800
20
208
430
874
1530
2170
4630
8330
13 100
27 400
30
167
345
702
1230
1740
3720
6690
10 600
22 000
40
143
295
601
1050
1490
3180
5730
9030
18 800
50
127
262
532
931
1320
2820
5080
8000
16 700
60
115
237
482
843
1200
2560
4600