Pipe Design (7)

Criticality: High
Progress: Addressed, Not Adequately
Score: 20
DOT Relevance: §192.101 – §192.125

Description of Key Area

Pipe design is addressed under Subpart C (Pipe Design) of 49 CFR 192. Per the Code, Subpart C prescribes the minimum requirements for the design of pipe.

Discussion of Criticality

Pipe design of hydrogen pipelines will encompass topics such as design formulae, wall thickness, design factor, joint factor, and derating. MAOP for high pressure hydrogen pipelines must be determined as well as the SMYS percentage. The MAOP and SMYS percentage should be consistent with materials to be used for pipe design.

Discussion of Progress

ASME STP/PT-003 was a 2005 study that evaluated the potential use of four piping and pipeline codes (ASME B31.1, ASME B31.3, ASME B31.8, and 49 CFR 192) for up to 103 MPa (15000 psi) hydrogen service. ASME B31.12 will address hydrogen piping standards specifically.

CGA G-5.6 is a non-mandatory standard for hydrogen pipes for the design, construction, pre-service, operation and monitoring, and safety of hydrogen pipes.

Recommendations

Standards for hydrogen pipe design, MAOP, and percentage SMYS should be established and the ASME B31.12 code is in development at this time. Standards established should be incorporated by reference into the federal code.