Progress: Addressed, Not Adequately
DOT Relevance: 192.621
Section 192.621 details the maximum allowable operating pressures for high pressure distribution systems.
It is not yet clear if MAOP determination methods need to be altered for hydrogen high pressure distribution systems.
ASME B31.12 will only allow location class 3 or 4 designs for hydrogen pipelines at this time (50% and 40% SMYS respectively). Pipe design may be changed from a stress based design to a strain based design. Discussions are scheduled for March of 2006.
Standards for maximum allowable operating pressure for hydrogen pipelines must be incorporated by reference into the federal code.