1308.4 Sizing of Gas Piping Systems.

Gas piping systems shall be of such size and so installed as to provide a supply of gas 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]

(2) Be recommended for that service by the manu facturer.

(2) Be recommended for that service by the manu facturer. (3) Be acceptable to the Authority Having Jurisdic tion. [NFPA 54:5.6.1.3]

tion. [NFPA 54:5.6.1.3]

TABLE 1308.4.1 APPROXIMATE GAS INPUT FOR TYPICAL APPLIANCES

[NFPA 54:TABLE A.5.4.2.1]

1308.4.1 Maximum Gas Demand. The volumetric flow rate of gas to be provided shall be the sum of the maximum inputs of the appliances served. The volumetric flow rate of gas to be provided shall be adjusted for altitude where the installation is above 2 000 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 pipe 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] 1308.4.2 Sizing Methods. Gas piping shall be sized in accordance with one of the following: (1) Pipe sizing tables or sizing equations in this chap ter.

(1) Pipe sizing tables or sizing equations in this chap ter. (2) Other approved engineering methods acceptable to

the Authority Having Jurisdiction.

(2) Other approved engineering methods acceptable to

the Authority Having Jurisdiction. (3) Sizing tables included in a listed piping system man ufacturer’s instructions. [NFPA 54:5.4.3]

(3) Sizing tables included in a listed piping system man ufacturer’s instructions. [NFPA 54:5.4.3] 1308.4.3 Allowable Pressure Drop. 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] Methods. 1308.5 Acceptable Piping Materials and Joining 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]

onnection 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] Methods. 1308.5 Acceptable Piping Materials and Joining 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]

1308.5.1 Materials. 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]

1308.5.1.1 Other Materials. 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.

1308.5.2 Metallic Pipe. Cast-iron pipe shall not be used. [NFPA 54:5.6.2.1]

1308.5.2.1 Steel and Wrought-Iron. Steel and wrought-iron pipe shall be not less than standard weight (Schedule 40) and shall comply with one of the following standards: (1) ASME B36.10 (2) ASTM A53 (3) ASTM A106 [NFPA 54:5.6.2.2] 1308.5.2.2 Copper and Copper Alloy. Copper and copper alloy pipe shall not be used where 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).

safe and suitable for the proposed service.

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Threaded copper, copper alloy, or aluminum alloy pipe shall not be used with gases corrosive to such material. 1308.5.2.3 Aluminum Alloy. 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] 1308.5.3 Metallic Tubing. Seamless copper, aluminum alloy, or steel tubing shall not be used with gases corrosive to such material. [NFPA 54:5.6.3]

1308.5.3.1 Steel. Steel tubing shall comply with ASTM A254. [NFPA 54:5.6.3.1] 1308.5.3.2 Copper and Copper Alloy. Copper and copper alloy tubing shall not be used where 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. 1308.5.3.3 Aluminum Alloy. 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, 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 54:5.6.3.3] 1308.5.3.4 Corrugated Stainless Steel. Corrugated stainless steel tubing shall be listed in accordance with CSA LC-1. [NFPA 54:5.6.3.4] 1308.5.4 Plastic Pipe, Tubing, and Fittings. 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] 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]

1308.5.4.1 Regulator Vent Piping. Plastic pipe and fittings used to connect regulator vents to remote vent terminations shall be PVC in accordance with UL 651. PVC vent piping shall not be installed indoors. [NFPA 54:5.6.4.2] 1308.5.4.2 Anodeless Risers. Anodeless risers shall comply with Section 1308.5.4.2.1 through Section 1308.5.4.2.3. [NFPA 54:5.6.4.3]

1308.5.4.2.2 Service Head Adapters andField-Assembled Anodeless Risers. 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 be in accordance with the requirements of Category I of ASTM D2513. The manufacturer shall provide the user qualified installation instructions.

[NFPA 54:5.6.4.3(2)] 1308.5.4.2.3 Undiluted Liquefied Petro-leum Gas Piping. 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)] 1308.5.5 Workmanship and Defects. 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] 1308.5.6 Protective Coating. Where in contact with material or atmosphere exerting a corrosive action, metallic piping and fittings coated with a corrosion-resistant material shall be used. External or internal coatings or linings used on piping or components shall not be considered as adding strength. [NFPA 54:5.6.6] 1308.5.7 Metallic Pipe Threads. Metallic pipe and fitting threads shall be taper pipe threads and shall comply with ASME B1.20.1. [NFPA 54:5.6.7.1]

1308.5.7.1 Damaged Threads. 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 54:5.6.7.2] 1308.5.7.2 Number of Threads. Field threading of metallic pipe shall be in accordance with Table 1308.5.7.2. [NFPA 54:5.6.7.3]

TABLE 1308.5.7.2 SPECIFICATIONS FOR THREADING METALLIC PIPE

[NFPA 54:TABLE 5.6.7.3]

1308.5.4.2.1 Factory-Assembled Anode- less Risers. 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)]

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1308.5.7.3 Thread Joint Compounds. 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 54:5.6.7.4] 1308.5.8 Metallic Piping Joints and Fittings. 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 54:5.6.8]

(d) Fittings in sizes 4 inches (100 mm) and

larger shall not be used indoors unless

(d) Fittings in sizes 4 inches (100 mm) and

larger shall not be used indoors unless approved by the Authority Having Jurisdiction. (e) Fittings in sizes 6 inches (150 mm) and

larger shall not be used unless approved by

(e) 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.

(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 mix

1308.5.8.1 Pipe Joints. Pipe joints shall be threaded, flanged, brazed, welded, or press-connect fittings made in accordance with CSA LC-4. Where nonferrous pipe is brazed, the brazing materials shall have a melting point in excess of 1000°F (538°C). Brazing alloys shall not contain more than 0.05 percent phosphorus. 1308.5.8.2 Tubing Joints. Tubing joints shall either be made with approved gas tubing fittings, be brazed with a material having a melting point in excess of 1000°F (538°C), or made by press-connect fittings in accordance with CSA LC-4. Brazing alloys shall not contain more than 0.05 percent phosphorus. [NFPA 54:5.6.8.2] 1308.5.8.3 Flared Joints. Flared joints shall be used in systems constructed from nonferrous pipe and tubing where experience or tests have demonstrated that the joint is approved for the conditions and where provisions are made in the design to prevent separation of the joints. [NFPA 54:5.6.8.3] Valves, Strainers, Filters). 1308.5.8.4 Metallic Pipe Fittings (Including Metallic pipe fittings shall comply with the following: (1) Threaded fittings in sizes exceeding 4 inches

(100 mm) shall not be used unless acceptable to

(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

Special fittings such as couplings; proprietary type joints; saddle tees; gland-type compression fittings; and flared, flareless, or compressiontype tubing fittings shall be as follows: (a) Used within the fitting manufacturer’s

pressure-temperature recommendations.

(a) Used within the fitting manufacturer’s

pressure-temperature recommendations. (b) Used within the service conditions antici pated with respect to vibration, fatigue,

(b) Used within the service conditions antici pated with respect to vibration, fatigue, thermal expansion, or contraction. (c) Installed or braced to prevent separation of

the joint by gas pressure or external physi

(c) Installed or braced to prevent separation of

the joint by gas pressure or external physical damage. (d) Acceptable to the Authority Having Juris diction.

(d) Acceptable to the Authority Having Juris diction. 1308.5.9 Plastic Piping, Joints, and Fittings. Plastic pipe, tubing, and fittings shall be installed in accordance with the manufacturer’s installation instructions. Section 1308.5.9.1 through Section 1308.5.9.4 shall be observed where making such joints. [NFPA 54:5.6.9]

(1) Threaded fittings in sizes exceeding 4 inches

(100 mm) shall not be used unless acceptable to the Authority Having Jurisdiction. (2) Fittings used with steel or wrought-iron pipe

shall be steel, copper alloy, bronze, malleable

(2) Fittings used with steel or wrought-iron pipe

shall be steel, copper alloy, bronze, malleable iron, or cast-iron. (3) Fittings used with copper or copper alloy pipe

shall be copper or copper alloy.

(3) Fittings used with copper or copper alloy pipe

shall be copper or copper alloy. (4) Fittings used with aluminum alloy pipe shall be

of aluminum alloy.

(4) Fittings used with aluminum alloy pipe shall be

of aluminum alloy. (5) Cast-iron fittings shall comply with the follow ing:

Cast-iron fittings shall comply with the follow ing: (a) Flanges shall be permitted. (b) Bushings shall not be used. (c) Fittings shall not be used in systems con taining flammable gas-air mixtures.

1308.5.9.1 Joint Design. 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 54:5.6.9(1)] 1308.5.9.2 Heat-Fusion Joint. Heat-fusion joints shall be made in accordance with qualified procedures that have been established and proven by test to produce gastight joints 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 54:5.6.9(2)] 1308.5.9.3 Compression-Type MechanicalJoints. 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 not less than the outside end of the compression fitting where installed. The stiffener shall be free of rough or sharp edges and shall not be a forced fit in the plastic. Split tubular stiffeners shall not be used. [NFPA 54:5.6.9(3)]

taining flammable gas-air mixtures.

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1308.5.11.5 Separated Flanges. When a flange joint is separated, the gasket shall be replaced.

[NFPA 54:5.6.11.4]