Which ASME B31 Code should be used for the construction of hydrogen piping systems?

At least three of the ASME B31 piping codes are logical choices:

• ASME B31.1, Power Piping
• ASME B31.3, Process Piping
• ASME B31.12 Hydrogen Piping and Pipelines

Considerations for code selection include:

• Requirements imposed by the authority having jurisdiction, whether by direct reference or by reference from another applicable code or standard.
• Code(s) used for other piping systems at the site. The people who have to operate and maintain the piping will be better served with fewer piping codes. The piping codes are complex and have different requirements. The people who have to operate and maintain the piping will likely be more successful if they have to learn requirements from fewer codes.

In the absence of these factors, ASME B31.12 is probably the most logical choice.

All three codes are suitable for liquid and gaseous hydrogen at pressures 15,000 psi (100 MPa) and higher. For pressures higher than 15,000 psi (100 MPa), the designation of high pressure fluid service in accordance with Chapter IX of ASME B31.3 may be a more economical choice and should be considered.