ASME B31.8, 2020 Edition, 2020 - Gas Transmission and Distribution Piping Systems (a) This Code covers the design, fabrication, installation, inspection, and testing of pipeline facilities used for the transportation of gas. This Code also covers safety aspects of the operation and maintenance of those facilities. (See Mandatory Appendix Q for scope diagrams.) This Code is concerned only with certain safety aspects of liquefied petroleum gases when they are vaporized and used as gaseous fuels. All of the requirements of NFPA 58 and NFPA 59 and of this Code concerning design, construction, and operation and maintenance of piping facilities shall apply to piping systems handling butane, propane, or mixtures of these gases. (b) This Code does not apply to (1) design and manufacture of pressure vessels covered by the BPV Code.1 (2) piping with metal temperatures above 450°F (232°C). (For low-temperature considerations, see section 812.) (3) piping beyond the outlet of the customer's meter set assembly. (Refer to ANSI Z223.1/NFPA 54.) (4) piping in oil refineries or natural gasoline extraction plants, gas treating plant piping other than the main gas stream piping in dehydration, and all other processing plants installed as part of a gas transmission system, gas manufacturing plants, industrial plants, or mines. (See other applicable sections of the ASME Code for Pressure Piping, B31.) (5) vent piping to operate at substantially atmospheric pressures for waste gases of any kind. (6) wellhead assemblies, including control valves, flow lines between wellhead and trap or separator, offshore platform production facility piping, or casing and tubing in gas or oil wells. (For offshore platform production facility piping, see API RP 14E.) (7) the design and manufacture of proprietary items of equipment, apparatus, or instruments. (8) the design and manufacture of heat exchangers. (Refer to appropriate TEMA2 standard.) (9) liquid petroleum transportation piping systems. (Refer to ASME B31.4.) (10) liquid slurry transportation piping systems. (Refer to ASME B31.4.) (11) carbon dioxide transportation piping systems. (Refer to ASME B31.4.) (12) liquefied natural gas piping systems. (Refer to NFPA 59A and ASME B31.3.) (13) cryogenic piping systems. (Refer to ASME B31.3.) (14) hydrogen piping systems. (Refer to ASME B31.12.) 1 BPV Code references here and elsewhere in this Code are to the ASME Boiler and Pressure Vessel Code. 2 Tubular Exchanger Manufacturers Association, 25 North Broadway, Tarrytown, NY 10591.

ASME B31.8 : 2018