Coffee Break Training: Hazardous Materials: Compressed Gas Cylinder Control Valve Pressure Relief Devices [open pdf - 130KB]
"Last week's Coffee Break Training described gas valves for high- and low-pressure cylinders. Today, we look at the PRDs [pressure relief devices] installed on the valves to minimize the chance of catastrophic cylinder rupture. Requirements for PRDs are established in Compressed Gas Association S-1.1, 'Pressure Relief Device Standards-Part 1-Cylinders for Compressed Gases.' The standard represents the minimum requirements for PRDs considered appropriate and adequate for cylinders with a water capacity of 1,000 pounds (454 kilograms) or less. […] When a cylinder is being filled, it is the filler's responsibility to verify that the PRD is correct for the product." This Coffee Break Training document includes a chart with pressure relief device designation and accompanying descriptions of each device.
Coffee Break Training - Fire Protection Series No. FP-2014-44
U.S. Fire Administration: http://www.usfa.fema.gov/