The Compressed Gas Association (CGA) published the first edition of C-23, Inspection of Tube Neck Mounting Surfaces, in 2012 and it’s being used by companies performing requalification of superjumbo and jumbo tube trailers and multiple-element gas containers (MEGCs). Inspection of the mounting surfaces on the necks of the large tubes (≥ 18″ OD) is mandatory every 10 years. Requalifiers remove the flanges used to mount the tubes to the trailer or skid framework and perform examinations of the necks to assess damage from worn threads (generalized thread wear) or pin marks (local thin areas). Specific acceptance and rejection criteria are used to accept the tubes for continued service. For those tubes that are rejected, FIBA can often repair the neck threads by rethreading the tubes in accordance with DOT regulations authorized in 49 CFR Section 180.212. Replacement of the flanges after an inspection is mandatory. FIBA manufactures new flanges for all thread sizes. Inspection of tube neck mounting surfaces can be performed at all FIBA facilities. Rethreading is done at our Massachusetts facilities. A copy of CGA C-23 is free for CGA members or it can be purchased from the CGA at http://www.cganet.com/. Please review the following PowerPoint presentation to learn more about inspection of tube neck mounting surfaces.