CGA S-1.3

This part of the Pressure Relief Device Standards presents the minimum requirements recommended by the Compressed Gas Association, Inc. (CGA), for pressure relief devices (PRDs) being used on compressed gas storage containers constructed in accordance with the American Society of Mechanical Engineers ASME Boiler & Pressure Vessel Code (ASME Code) or the equivalent. While these standards are written specifically to cover compressed gas as defined in 3.3, the procedures are applicable to storage containers with a maximum allowable working pressure (MAWP) exceeding 15 psig (103 kPa).

It is recommended that containers use PRDs that meet the applicable requirements of the edition of the ASME Code or other applicable regulations, codes, standards, or specifications in effect at the time of manufacture. The container PRDs shall also meet the requirements of this publication, except containers for liquefied petroleum gas and anhydrous ammonia shall use PRDs meeting the applicable requirements of the following two standards:

• NFPA 58, Liquefied Petroleum Gas Code; and
• CGA G-2.1, American National Standard Safety Requirements for the Storage and Handling of Anhydrous Ammonia (ANSI K61.1).

A number of states and cities have pressure vessel laws and regulations that include requirements for PRDs. Manufacturers and users are cautioned that in some instances the relief devices recommended in this standard might not be acceptable unless special permission is obtained from the authority having jurisdiction.

The purpose of this standard is to complement the requirements of various regulations, codes, standards, or specifications applicable to storage containers for compressed gases. In case of conflict, the requirements of the regulations, codes, standards, or specifications of the authorities having jurisdiction over such containers shall apply. It is recommended that containers fabricated after December 31, 1995, use PRDs that meet the requirements of this edition of CGA S-1.3.

CGA believes that reclosing PRDs on a container shall be able to handle all operational emergency conditions except fire and liquid displacement from a runaway fill. Where fire or liquid overfill is a credible emergency event, reclosing or nonreclosing PRDs shall be provided.