CGA C-20:2021

This standard identifies and describes the various acceptable UT methods (also known as ultrasonic examination [UE] methods) that may be used in place of internal visual inspection and hydrostatic requalification methods used to examine certain metallic, U.S. Department of Transportation (DOT)/Transport Canada (TC) 3-series gas cylinders and tubes as mandated by Title 49 of the U.S. Code of Federal Regulations (49 CFR) and TC’s Transportation of Dangerous Goods Regulations, and cylinders manufactured under certain DOT special permits or TC equivalency certificates.