ASME B31.4 covers piping transporting liquids between production facilities, tank farms, natural gas processing plants, refineries, pump stations, ammonia plants, terminals (marine, rail, and truck), and other delivery and receiving points. Piping here consists of pipe, flanges, bolting, gaskets, valves, relief devices, fittings, and the pressure-containing parts of other piping components. It also includes hangers and supports, and other equipment items necessary to prevent overstressing the pressure-containing parts. ASME B31.4 does not include support structures such as frames of buildings, stanchions, or foundations, or any equipment. Requirements for offshore pipelines are found in Chapter IX. Requirements for CO2 piping are found in Chapter X. Requirements for slurry piping are found in Chapter XI. Also included within the scope of this Code are: (a) primary and associated auxiliary liquid petroleum and liquid anhydrous ammonia piping at pipeline terminals (marine, rail, and truck), tank farms, pump stations, pressure reducing stations, and metering stations, including scraper traps, strainers, and prover loops; (b) storage and working tanks, including pipe-type storage fabricated from pipe and fittings, and piping interconnecting these facilities; (c) liquid petroleum and liquid anhydrous ammonia piping located on property which has been set aside for such piping within petroleum refinery, natural gasoline, gas processing, ammonia, and bulk plants; (d) those aspects of operation and maintenance of Liquid Pipeline Systems relating to the safety and protection of the general public, operating company personnel, environment, property, and the piping systems. Key changes to this revision include new requirements for CO2 piping and the incorporation of requirements of ASME B31.11 into ASME B31.4. This Code prescribes comprehensive solutions for materials, design, fabrication, assembly, erection, testing and inspection. It also serves as a companion to ASME�¢??s other B31 codes on piping systems. Together, they remain essential references for anyone engaged with piping.