American Society of Mechanical Engineers
ASME B31 Series

(See B31.12 below for Hydrogen Piping)

Note: ASME is a worldwide engineering society, and many

of its standards are recognized internationally.

Identification ASME B31.1   
     Power Piping
Scope This code prescribes minimum requirements for the design, materials, fabrication, erection, test, and inspection of power and auxiliary service piping systems for electric generation stations, industrial institutional plants, central and district heating plants.


Status Published and available through ASME.

Identification ASME B31.3   
     Process Piping


Scope Rules for this section have been developed considering piping typically found in petroleum refineries; chemical, pharmaceutical, textile, paper, semiconductor and cryogenic plants; and related processing plants and terminals.
Status Published and available through ASME.

Identification ASME B31.4
    Pipeline Transportation Systems for Liquid Hydrocarbons and Other Liquids


Scope This code prescribes requirements for the design, materials, construction, assembly, inspection, and testing of piping transporting liquids such as crude oil, condensate, natural gasoline, natural gas liquids, liquefied petroleum gas, carbon dioxide, liquid alcohol. Liquid anhydrous ammonia, and liquid petroleum products between producers’ lease facilities, tank farms, natural gas processing plants, refineries, stations, ammonia plants, terimals and other delivery and receiving points.

Published and available through ASME.

Identification ASME B31.8
Gas Transmission and Distribution Piping Systems
Scope This code covers the design, fabrication, installation, inspection, testing, and safety aspects of operation and maintenance of gas transmission and distribution systems, including gas pipelines, gas compressor stations, gas metering and regulation stations, gas mains, and service lines up to the outlet of the customers meter set  assembly.
Status Published and available through ASME.

Identification ASME B31.8S
Managing System Integrity of Gas Pipelines


Scope This standard applies to on-shore pipeline systems constructed with ferrous materials and that transport gas.  The principals and processes embodies in integrity management are applicable to all pipeline systems.


Status Published and available through ASME.

Identification ASME B31.12
Hydrogen Piping and Pipelines



This standard activity has been formed to develop a new code for hydrogen piping and pipelines that contains requirements specific to hydrogen service in power, process, transportation, distribution, commercial and residential applications. It includes equivalent information found in B31.3, B31.8 and NFPA 54 for natural gas.

This Code is applicable to piping in gaseous and liquid hydrogen service and to pipelines in gaseous 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. This Code 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.



Published 2009. 2nd edition published 2011. 3rd edition published 2014.


Available at

Work has started on the next edition, which is targeted to include the commercial/ residential requirements that can be used for the fabrication and installation of hydrogen appliances which operate below 290 psig (2.0 MPa) like fuel cells.


Chairman Lou Hayden
Contact Adam Maslowski, ASME