ASME B31.12 Standard on Hydrogen Piping and Pipelines contains requirements for piping in gaseous and liquid hydrogen service and pipelines in gaseous hydrogen service. The general requirements section covers materials, brazing, welding, heat treating, forming, testing, inspection, examination, operating, and maintenance. The industrial piping section covers requirements for components, design, fabrication, assembly, erection, inspection, examination, and testing of piping. This Code is applicable to piping in gaseous and liquid hydrogen service and to pipelines in gaseous hydrogen service. B31.12 is applicable up to and including the joint connecting the piping to associated pressure vessels and equipment but not to the vessels and equipment themselves. It is also applicable to the location and type of support elements, but not to the structure to which the support elements are attached. B31.12 is presented in the following parts: (a) Part GR — General Requirements. This part contains definitions and requirements for materials, welding, brazing, heat treating, forming, testing, inspection, examination, operation, and maintenance. (b) Part IP — Industrial Piping. This part includes requirements for components, design, fabrication, assembly, erection, inspection, examination, and testing of piping. (c) Part PL — Pipelines. This part sets forth requirements for components, design, installation, and testing of hydrogen pipelines. It is required that each part be used in conjunction with the General Requirements section but independent of the other parts. It is not intended that this edition of this Code be applied retroactively to existing hydrogen systems. Key changes to this revision include: New Section GR-6.3 for Quality System Functions; New table for Required Nondestructive Examinations added to Chapter IP-10; New paragraphs for Quality Control Examinations, Extent of Required NDE Examainations, Acceptance Criteria, Procedures, and Types of Examination added to Chapter IP-10; Updated references throughout; Equations for thickness of permanent blanks and of straight pipe have been updated. B31.12 serves as a companion to the other codes in ASME’s B31 series on Pressure Piping. Together, they remain essential references for anyone engaged with piping.