CGA G-5.5:2014

This publication presents design guidelines for hydrogen vent systems used in gaseous and liquid hydrogen systems at user sites and provides recommendations for safe operation of these vents. It begins at the discharge port of safety devices and other components that control the release of hydrogen and ends at the point where hydrogen concentration in the atmosphere is below the lower flammable limits.
Pressure relief devices (PRDs) for cylinders and tube trailers required by U.S. Department of Transportation (DOT) in Title 49 of the U.S Code of Federal Regulations (49 CFR) are not covered in the scope of this publication.