BS EN 13953:2020 pdf free.LPG equipment and accessories一Pressure relief valves for transportable refillable cylinders for Liquefied Petroleum Gas (LPG).
BS EN 13953 Hot stamped brass shall be non-porous and shall be suitable for machining or other processes.Sand-cast brass shall not be used. Leaded brass shall be CW614N, in accordance with EN 12164, or CW617N in accordance with EN 12420 or EN 12165. Cold drawn brass rods up to 45 mm wide in cross-section shall only be used after heat treatment and testing for internal cracking. Cold drawn brass rods greater than 45 mm wide in cross-section shall not be used. Components produced from stamping brass shall not exhibit cold shuts, also known as folds, or surface defects such as a crack which may lead to leakage or component failure. Springs shall be manufactured from stainless steel wire and shall contain not less than 16 % chromium and not less than 6 % nickel.Non-metallic materials in contact with LPG shall be compatible with LPG and shall not fail during the valve service life. They shall not distort, harden, swell or adhere to the body or seat face to such an extent as to impair the function of the valve. Non-metallic materials which are exposed to UV shall be UV resistant as confirmed by the material manufacturer.PRVs for cylinders of a water capacity greater than 7,5 I shall be designed to operate with a pop action within the overpressure of the valve. The valve components shall be designed with adequate strength and clearances to ensure correct operation in service.Design and construction of PRVs shall ensure that the fitting of a PRV to the cylinder under normal conditions and in accordance with the instructions of the manufacturer does not affect its performance. When a PRV is integral with a cylinder valve, it shall be ensured that fitting of the cylinder valve to the cylinder in accordance with the instructions of the manufacturer does not affect the performance of the PRV.The sealing element carrier shall be manufactured from a metallic material with a minimum melting point of 450 °C.The design shall incorporate guiding arrangements for the sealing element to ensure reliable operation and leak tightness.The sealing element shall be secured to prevent it becoming loose in operation. BS EN 13953 pdf download.