Pressure vessel pressure test and leak test

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1.1 The manufactured containers shall undergo pressure tests and leak tests in accordance with the provisions of the design documents. 1.2 During the voltage withstand test and leakage test, if a pressure gauge is used to measure the test pressure, two pressure gauges with the same range and that have passed calibration should be employed. The range of the pressure gauge should be 1.5 to 3 times the test pressure, preferably 2 times the test pressure. The accuracy of the pressure gauge must be at least 1.6 grade, and the diameter of the dial must be no less than 100 mm. 1.3 The opening reinforcement rings of the container should have the quality of their weld joints checked using compressed air at a pressure of 0.4 MPa to 0.5 MPa prior to testing. 1.4 Pressure testing 1.4.1 Pressure testing is divided into hydraulic testing, pneumatic testing, and combined gas-liquid pressure testing; the testing shall be carried out in accordance with the methods specified in the design documents. 1.4.2 The test pressure for the pressure resistance test and the strength verification when necessary shall comply with the provisions of GB 150.1. 1.4.3 Before the voltage withstand test, the fasteners at all connection points of the container shall be fully installed and properly tightened ； Appropriate measures shall be taken to ensure the safety of temporary pressure-bearing components assembled for voltage withstand testing. 1.4.4 The pressure gauge for testing shall be installed at the top of the location where the container under test is placed. 1.4.5 During the pressure holding phase of the withstand voltage test, continuous pressure application to maintain the test pressure shall not be used; during the test, fasteners shall not be tightened under pressure, nor shall any external force be applied to the components under stress. 1.4.6 For repairs carried out after the pressure test, if the extent of the repair on a vessel exceeds half of its wall thickness, a new pressure test must be conducted. 1.5 Hydraulic testing 1.5.1 Water is generally used as the testing fluid; once the test is successful, the water should be drained immediately and the area dried out ； When it is not possible to completely drain the water after drying, for austenitic stainless steel containers, the chloride content in the water should be kept at no more than 25 mg/L. 1.5.2 When the metal temperature of the test container walls is close to that of the liquid, the pressure can be increased slowly to the design pressure; once no leaks are detected, the pressure can be further increased to the specified test pressure, with the pressure being maintained for at least 30 minutes ； Then it is reduced to the design pressure, and the pressure is held at that level for a sufficient duration for inspection; the pressure must remain constant during this inspection period. 1.5.3 Acceptance criteria for hydraulic testing: During the test, the container shall show no leaks, no visible deformation, and no abnormal noises. 1.5.4 After the hydraulic test is completed, the liquid should be drained and the interior should be dried with compressed air. 1.6 Leak test 1.6.1 The container must pass the pressure resistance test before it can undergo a leak test. 1.6.2 Leak tests include airtightness tests, ammonia leak detection tests, halogen leak detection tests, and helium leak detection tests, which shall be carried out in accordance with the methods and requirements specified in the design documents.