BS ISO 5208:2015 pdf download – Industrial valves — Pressure testing of metallic valves

BS ISO 5208:2015 pdf download – Industrial valves — Pressure testing of metallic valves 3.1.2 When a purchaser specifies examinations or testing to be witnessed as described in 3.1.1, the valve manufacturer shall give notice to the purchaser at least five working days prior to the purchase order specified activity. 3.2 Witnessing If pressure testing in the presence of a representative of the purchaser is specified for valves that are in stock, painted or coated valves from stock may be retested without removal of painting or coating. 3.3 Closure pressure testing options A purchaser may specify, in a valve procurement purchase order, optional closure testing. See Table 1. 4 Requirements for pressure testing 4.1 Forewarning A user of this International Standard needs to properly take into account the hazard involved with working with pressurized gases and liquids. 4.2 Location Pressure tests shall take place either at the site of the valve manufacture or at a test facility under the supervision of the valve manufacturer. 4.3 Test equipment 4.3.1 The test equipment shall be of such a design, that it does not subject the valve to externally applied loads that may affect the results of the test. When end-clamping devices are used, the valve manufacturer shall be able to demonstrate that, during the valve closure test, they do not serve to reduce the resultant leakage. Valves designed for installation between flanges, e.g. wafer style check or butterfly valves, shall not have test equipment clamping forces applied that are so great as to bear upon the pressure test results. 4.3.2 When equipment such as volume loss detection devices are used, the manufacturer shall be capable of demonstrating equivalence of the system with the requirements of this International Standard. 4.4 Pressure measuring equipment The equipment used for measuring test fluid pressure shall measure the fluid pressure with an accuracy of ± 5 % of the required test pressure. 4.5 Shell surfaces Before the shell test, valves shall not be externally painted or otherwise coated with materials capable of sealing against leakage from external surfaces of the shell. However, valves with internal liners, internal linings or internal coatings that form a design feature of the valve may be tested with the liner, lining or coating in place. In the event a purchaser specifies a retest of the shell test of valves that have been painted, retesting may be without removal of external paint or...