Gaps in requirements for heavy duty hydrogen vehicles have been addressed. See 4.4.2 for hydrogen storage system mounting and installation requirements and 5.2.2.4.1 for guidance in conducting the localized fire test.
The table for pre-approved materials for high pressure hydrogen compatibility in Appendix B.2 was re-formatted to improve understanding. Materials on the table were reviewed and adjusted.
Editorial and format errors were corrected in Appendix B.3 including the re-numbering of sections. Procedures were updated and streamlined throughout Appendix B.3 to improve the quality of test results and expedite verification of materials. Appendix B.3.3 was deleted as a normative requirement as recent test data indicate that Appendix B3.2 is adequate for assessment of fatigue crack growth. References were also added in Appendix B.3 to a newly published standard, CSA CHMC 1, for the verification of the compatibility of materials with compressed hydrogen.
The localized fire test in Appendix C.12 was updated to harmonized acceptance criteria with the approved GTR for hydrogen and fuel cell vehicles. Additional requirements for the test configuration have also been added to address variability in test results that have noted in recent testing.
Requirements for burst ratios of the containers in the Compressed Hydrogen Storage System (CHSS) were modified in Appendix H. Both the minimum allowable prescribed burst ratio and the test method to empirically determine the minimum acceptable value were updated.