scope:

This publication provides guidelines to assist in the selection of a PRD for a cylinder with UN stamp markings and the selection of a CGA valve outlet for a cylinder with UN stamp markings. It is important to note that some UN marked cylinders may also be marked with U.S. Department of Transportation (DOT) and/or Transport Canada (TC) markings. This publication also applies to the determination of specific setting of PRDs on comparable DOT specification and UN marked cylinders. It also details the proper stamp marking that needs to be on the PRD.

This publication applies to high pressure seamless steel and aluminum alloy cylinders.

This publication does not apply to CGA valve outlets on manifolded cylinders and tubes or to tubes.