Hydrogen Piping and Pipelines

ASME B31.12 is applicable to piping and pipelines handling gaseous hydrogen and gaseous hydrogen mixtures and to piping in liquid hydrogen service. This Code 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 applicable to the location and type of support elements but not to the structure to which the support elements are attached. The design for pressure and temperature shall be in accordance with the requirements of Part IP for industrial piping and Part PL for pipelines.

This Code is presented in the following parts and appendices:

(a) Part GR — General Requirements. Part GR contains requirements applicable to and referenced by other parts. It contains definitions and requirements for materials, welding, brazing, heat treating, forming, testing, inspection, examination, operation, and maintenance. It also contains quality system topics common to the other parts.

(b) Part IP — Industrial Piping. Part IP includes requirements for components, design, fabrication, assembly, erection, inspection, examination, and testing of piping.

(c) Part PL — Pipelines. Part PL sets forth requirements for components, design, installation, and testing of hydrogen pipelines.

(d) Mandatory Appendices I through IX

(e) Nonmandatory Appendices A through F

Each part defines requirements for piping or pipelines, as applicable, within its scope. The requirements are different for different aspects of components, design, fabrication, installation, assembly, erection, inspection, examination, and testing. It is required that each part be used in conjunction with the General Requirements section but independent of the other parts. The joint connecting piping governed by two different parts shall be subject exclusively to the requirements of one of the two parts. It is not intended that this edition of this Code be applied retroactively to existing hydrogen systems.

Key changes to this revision include: 

• An updated introduction
• Table GR-2.1.1-2 Revised in its entirety
• Section GR-3.9.2 Reinstated by errata
• Chapter GR-6 Revised in its entirety
• Chapter IP-6 Revised in its entirety
• Section IP-10.4.5.2 Revised in its entirety
• Table PL-2.5.2-1 Revised in its entirety
• Table PL-2.5.5-1 Revised in its entirety
• Table A-2-1 Revised in its entirety
• Section A-2.5 Revised in its entirety
• Section A-2.10 Revised in its entirety

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.

Careful application of these ASME B31 Codes will help users to comply with applicable regulations within their jurisdictions, while achieving the operational, cost and safety benefits to be gained from the many industry best-practices detailed within these volumes.

Intended for manufacturers, designers, operators, owners and inspectors of hydrogen piping and pipelines, plus all potential governing entities.

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