CGA/GAS - CGA S-1.2
PRESSURE RELIEF DEVICE STANDARDS PART 2—PORTABLE CONTAINERS FOR COMPRESSED GASES
|Publication Date:||1 January 2009|
It is recognized that there are portable containers that conform to the specification requirements of DOT and TC that are used in services beyond the jurisdiction of either of these authorities. In such cases, it is recommended that international, state, provincial, local, or other authorities having jurisdiction over these containers use this publication to determine adequate PRD requirements provided that the portable containers are charged with gas and maintained in accordance with DOT or TC regulations.
It is further recognized that there may be portable containers used in services not within the jurisdiction of DOT or TC that do not conform to the specification requirements of either authority. It is recommended that the authorities having jurisdiction over such portable containers use this publication to determine PRD requirements provided that such portable containers are considered by the authority as having a construction at least equal to the equivalent DOT or TC specification requirements, and further provided that the portable containers are charged with gas and maintained in accordance with DOT or TC regulations.
PRD requirements for tank cars including multi-unit tank car tanks can be found in Title 49 of the U.S. Code of Federal Regulations (49 CFR) Part 179 .
PRD standards for cylinders with water capacity less than 1000 lb (454 kg) and DOT specifications 3AA, 3AAX, and 3T tubes can be found in CGA S-1.1, Pressure Relief Device Standards-Part 1-Cylinders for Compressed Gases . PRD standards for stationary ASME vessels can be found in CGA S-1.3, Pressure Relief Device Standards-Part 3-Stationary Storage Containers for Compressed Gases .
NOTE-In 49 CFR Part 171.7 the 1980 edition of this publication is incorporated by reference .
The purpose of this standard is to complement the requirements of various regulations, codes, standards, or specifications applicable to portable containers. In case of conflict, the requirements of the regulations, codes, standards, or specifications of the authorities having jurisdiction over such portable containers shall apply. It is recommended that portable containers fabricated after December 31, 1995, use PRDs that meet the requirements of this edition.
CGA believes using reclosing PRDs on a container shall handle all operational emergency conditions except fire, for which reclosing or nonreclosing PRDs shall be provided. The operational emergency conditions referred to shall include but are not be limited to loss of vacuum, runaway fill, and uncontrolled operation of pressure build-up devices. However, DOT regulations require that containers for flammable products shall have pressure relief valves designed to maintain the container pressure below 120% of the maximum allowable working pressure (MAWP) (DOT design pressure) of the container during fire conditions.