CGA PS-43 (R2023)

Tubes transported in the United States may be stamped with U.S. Department of Transportation (DOT) stamp markings, United Nations (UN) stamp markings, or a combination thereof. Numerous questions arise as to the requirements for the selection of pressure relief devices (PRDs) that are to be installed on tubes when required.

This position statement provides guidance to assist in the selection of a PRD for DOT-3AX, DOT-3AAX, DOT-3T, and UN 11120 tubes. This publication applies to the determination of the setting of the rupture disk in CG-1, CG-4, and CG-5 type PRDs on comparable DOT specification and UN marked tubes. It also details the proper stamp marking that is required to be on the PRD.