Japan, Dec. 5 -- ClassNK has issued a General Design Approval (GDA) for the low-pressure LCO? cargo tank developed by Mitsubishi Shipbuilding Co., Ltd., the company announced, citing the approval as evidence of compliance with relevant rules at the detailed design level.This marks the world's first GDA for a liquefied CO? cargo tank made of KF460 steel and using a technology that omits post-weld heat treatment (PWHT). The GDA includes a tank safety assessment process based on Engineering Critical Assessment (ECA) to allow omission of PWHT.ClassNK had issued an Approval in Principle (AiP) for Mitsubishi Shipbuilding's ECA evaluation process in September 2024. The structural integrity under specified design temperature conditions was demonstr...