Rules for the Process Piping Code Section B31.3 have been developed considering piping typically found in petroleum refineries; chemical, pharmaceutical, textile, paper, semiconductor, and cryogenic plants; and related processing plants and terminals. This code prescribes requirements for 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. See Fig. 300.1.1 for a diagram illustrating the application of B31.3 piping at equipment connections. Also included within the scope of this Code is piping which interconnects pieces or stages within a packaged equipment assembly. **** PLEASE NOTE.****Previously titled Chemical Plant and Petroleum Refinery Piping.