There is a newer edition of this document available. ASME has been defining piping safety since 1922. ASME B31.3 contains requirements for piping typically found in petroleum refineries; chemical, pharmaceutical, textile, paper, semiconductor, and cryogenic plants; and related processing plants and terminals. It covers materials and components, design, fabrication, assembly, erection, examination, inspection, and testing of piping. This Code applies to piping for all fluids including: (1) raw, intermediate, and finished chemicals; (2) petroleum products; (3) gas, steam, air and water; (4) fluidized solids; (5) refrigerants; and (6) cryogenic fluids. Also included is piping which interconnects pieces or stages within a packaged equipment assembly. Key changes to this revision include adding a new Chapter X on High Purity Piping, updating Table A-1 Basic Allowable Stress Tables in its entirety, and adding Table A-3 Basic Allowable Stress Tables in metric units. B31.3 is one of ASME’s most popular codes, widely adopted by jurisdictions worldwide. It serves as a companion to ASME’s B31.1 Code on Power Piping as well as to the other codes in ASME’s B31 series. Together, they remain essential references for anyone engaged with piping.