MSC.1-Circ.1622-Rev.1？-？Revised？Guidelines？For？The？Acceptance？Of？Alternative？Metallic？Materials？For？Cryogenic？Service

INTERNATIONALEMARITIMEORGANIZATION4 ALBERT EMBANKMENTLONDON SE1 7SRTelephone:+44(0)2077357611Fax:+44(0)2075873210MSC.1/Circ.1622/Rev.11Juy2024REVISED GUIDELINES FOR THE ACCEPTANCE OF ALTERNATIVE METALLICMATERIALS FOR CRYOGENIC SERVICE IN SHIPS CARRYING LIQUEFIED GASES INBULK AND SHIPS USING GASES OR OTHER LOW-FLASHPOINT FUELSThe Maritime Safety Committee,at its 102nd session (4 to 11 November 2020).acknowledging a potential need for alternative metallic materials to be used for the constructionand safe operation of low-temperature fuel and cargo-carrying ships and the need for guidancein this respect,approved the Guidelines for the acceptance of alternative metallic materials forcryogenic service in ships carrying liquefied gases in bulk and ships using gases or otherlow-flashpoint fuels (MSC.1/Circ.1622),prepared by the Sub-Committee on Carriage ofCargoes and Containers(CCC),at its sixth session(9 to 13 September 2019).The Maritime Safety Committee,at its 105th session(20 to 29 April 2022),approvedamendments to the Guidelines (MSC.1/Circ.1648),prepared by the Sub-Committee onCarriage of Cargoes and Containers(CCC),at its seventh session(6 to 10 September 2021).3The Maritime Safety Committee,at its 108th session (15 to 24 May 2024),havingqualified high manganese austenitic steel for ammonia service,and in order to revise additionalcompatibility test requirements for ammonia service,approved the Revised Guidelines for theacceptance of alternative metallic materials for cryogenic service in ships carrying liquefiedgases in bulk and ships using gases or other low-flashpoint fuels,as set out in the annex,prepared by the Sub-Committee on Carriage of Cargoes and Containers(CCC),at its ninthsession(20 to 29 September 2023).The Revised Guidelines incorporate the amendments in MSC.1/Circ.1648 andprovide detailed guidance on how to document alternative metallic materials for their suitabilityand compliance with the IGC and IGF Codes,and a framework for evaluation and approval ofalternative metallic materials for cryogenic service.5Member States are invited to bring the annexed Revised Guidelines to the attentionof all parties concerned.6This circular supersedes MSC.1/Circ.1622 and revokes MSC.1/Circ.1648.I:CIRCMSC1MSC 1-Circ.1622-Rev.1.docxNAVIGATINGTHE FUTURE:SAFETY FIRST!