CSA ANSI PRD-1:2013 pdf download.Pressure relief devices for natural gas vehicle (NGV) fuel containers
1.1 CSA ANSI PRD-1 establishes minimum requirements for pressure relief devices intended for use on fuel containers that comply with ANSI/CSA NGV2, Compressed Natural Gas Vehicle (NGV) Fuel Containers,FMVSS 304, Federal Motor Vehicle Safety Standards, 49 CFR Part 571.304, Compressed Natural Gas Fuel Container Integrity, CSA B51, Part 2, High Pressure Cylinders for On-Board Storage of Natural Gas as a Fuel for Automotive Vehicles and/or ISO 11439 Gas Cylinders - High Pressure Cylinders for the Onboard Storage of Natural Gas as a Fuel for Automotive Vehicles.
1.1.1 Pressure relief devices designed to comply with this standard are expected to be used with natural gas fuel containing no more than two percent hydrogen by volume.
Resistance to chloride stress corrosion cracking shall be taken under consideration if selecting stainless steel materials. Resistance to stress corrosion cracking and sustained load cracking shall be taken under consideration if selecting aluminum materials. Resistance to sulfide stress cracking shall be taken under consideration if selecting steel materials.
1.2 Relevant documents
Documents which apply to fuel container installation and vehicle systems include FMVSS 303, Federal Motor Vehicle Safety Standards, 49 CFR Part 571.303, Fuel System Integrity of Compressed Natural Gas Vehicles, CS 301.2, Transport Canada, Motor Vehicle Safety Regulations, Schedule IV, CNG Fuel System Integrity, NFPA 52, Vehicular Fuel Systems Code, and B109, Natural Gas for Vehicles Installation Code.Other regulations, standards or codes may permit or require the use of pressure relief devices certified to comply with this standard. Additional service conditions or requirements beyond the scope of this document are the responsibility of those standards development organizations or the authority having jurisdiction.
1.4 Notes
Fuel containers may accidentally be exposed to fire or elevated temperature. These conditions may act to increase the contained pressure and/or to degrade the structural materials, depending on the container type and materials of construction. A pressure relief device (PRD) provides a means to vent the fuel container under these conditions.
A specific pressure relief device may not be suitable for all container types, sizes and/or installations.Fuel container or installation standards may require that a pressure relief device be tested in conjunction with other components.
CGA S-1.1, Pressure Relief Device Standards Part 1-Cylinders for Compressed Gasses states:“- relief devices may not prevent burst of a cylinder under all conditions of fire exposure. When the heat transferred to the cylinder is localized, intensive, and remote to the relief device, or when the fire builds rapidly, such as in an explosion, and is of very high intensity, the cylinder can weaken sufficiently to rupture before the relief device operates, or while it is operating".CSA ANSI PRD-1 pdf download.