BS ISO 19882-2018 pdf free download.Gaseous hydrogen — Thermally activated pressure relief devices for compressed hydrogen vehicle fuel containers
5 Quality assurance
Quality system programs shall be established and operated to demonstrate that pressure relief devices are produced in accordance with the qualified design. 6 General requirements
6.1 Material requirements Materials normally in contact with hydrogen shall be determined to be acceptable in hydrogen service, with the consideration of hydrogen embrittlement and hydrogen accelerated fatigue. The performance tests cannot guarantee that all cases and conditions of the hydrogen service are validated, so it is still incumbent on the designer/builder to carefully screen materials of construction for their intended use. The materials and design shall be such that there is no significant change in the functioning of the device, deformation or mechanical change in the device, and no harmful corrosion, deformation or deterioration of the materials when subject to the service conditions given in Clause 4.
NOTE 1 Material performance data and/or acceptance criteria in hydrogen environments can be found in the ISO 11114 series, the Sandia National Laboratory Technical Reference for Hydrogen Compatibility of Materials, ANSI/AIAA G-095, ANSI/CSA CHMC 1, ASME B31.12, SAE J2579:2013, Appendix B or in equivalent national requirements.
NOTE 2 Some fusible alloys can contain heavy metals that can be considered environmentally unacceptable by some customers and which can be prohibited by some jurisdictions. Non-metallic materials normally in contact with hydrogen shall be verified to be acceptable in the hydrogen service. Consideration shall be given to the fact that hydrogen diffuses through these materials more easily than through metals; therefore the suitability of materials shall be verified. Non-metallic materials shall retain their mechanical stability with respect to strength (fatigue properties, endurance limit, creep strength) when exposed to the full range of service conditions and lifetime as specified by the container manufacturer. Materials shall be sufficiently resistant to the chemical and physical action of the fluids that they contain and to environmental degradation. The chemical and physical properties necessary for operational safety shall not be significantly affected within the scheduled lifetime of the equipment unless a replacement is foreseen; specifically, when selecting materials and manufacturing methods, due account shall be taken of the material’s corrosion and wear resistance, electrical conductivity, impact strength, aging resistance, the effects of temperature variations, the effects arising when materials are put together (for example, galvanic corrosion), the effects of ultraviolet radiation, and to the degradation effects of hydrogen on the mechanical performance of a material.
6.2 Design requirements
The design shall be such that, once activated, the device fully vents the contents of the fuel container. The design should minimize the possibility of external hazards (e.g. projectiles) resulting from the activation of the device. Any material released shall not interfere with the proper venting of the pressure relief device.
The pressure relief device shall be designed to address degradation from creep or plastic deformation. The design or manufacturing process should account for the effects of material defects, particularly casting and shrinkage voids, which adversely impact the robustness of the design.
6.3 Flow capacity The flow capacity shall be indicated in the manufacturer’s published literature and verified by the flow capacity test under 7.13. The adequacy of the flow capacity of pressure relief devices for a given application shall be demonstrated by bonfire testing in accordance with ISO 19881, ANSI HGV 2, CSA B51 Part 2, EC79/EU406, SAE J2579, or the UN GTR No. 13 for fuel cell vehicles and by the minimization of the hazardous effects of the pressure peaking phenomenon which can take place during high flow rate releases from small diameter vents in enclosed spaces.
6.4 Rework and repair New pressure relief devices that do not meet the requirements of this document may be reworked or repaired as long as they satisfy the requirements of this document.
6.5 Failure modes and effects analysis (FMEA) Design FMEA and Process FMEA shall be performed for pressure relief devices. The documents shall be made available for review by fuel container or vehicle manufacturers upon request. A verification of the existence of these documents satisfies the intent of this provision.
NOTE FMEA is a methodology used in the automotive industry to identify potentially hazardous failure modes of safety devices and recommend changes in design, manufacturing, inspection or testing which eliminate such failure modes or minimize their effects. FMEA is applied to both device design and to the manufacturing and assembly process to identify corrective actions that improve device reliability and safety. Available references include SAE J1739.BS ISO 19882 pdf  download.