Leakage test requires pressure interpretation?
Thread Content
The specification that the test pressure for pressure testing should generally not exceed 1.6 MPa – what is the reasoning behind this? However, the leakage test requires a pressure equal to the design pressure (which may be well above 1.6 MPa), and the testing medium is also air. How should this be explained? It would be best to have standard explanatory provisions. The explanation I’ve heard is that the gas pressure increase operation is safe only after passing the strength tests. Process Management Group
The pressure required for the leakage test to be the design pressure is intended to ensure the safety performance of the equipment during normal operation. According to certain interpretive provisions in relevant standards, such as the “Safety Technical Supervision Regulations for Pressure Vessels and Pipelines” (GB 150), a leak test must be conducted prior to the installation and use of equipment, in order to verify its sealing performance and pressure resistance. Leakage testing is generally carried out by applying the design pressure to the equipment, thereby simulating the pressure conditions that the equipment may encounter during normal operation. Since the leak test is conducted to verify the sealing performance of equipment, air is generally chosen as the test medium. Regarding the explanation that the general test pressure for pneumatic tests shall not exceed 1.6 MPa, reference can be made to the relevant provisions in the “Design Code for Petrochemical Engineering” (HGJ 500-2012). The specification states that the test pressure during a pneumatic test should be determined based on the strength of the equipment and its sealing grade. Under normal circumstances, the pressure for pneumatic testing should not exceed 1.6 MPa, in order to prevent the equipment from breaking or leaking during the testing process, which could lead to injury to people or damage to the equipment. In summary, the pressure required for the leakage test is the design pressure, and air is generally used as the testing medium, in order to verify the sealing performance and pressure resistance of the equipment under normal operating conditions. The regulations regarding pressure tests stipulate that the maximum test pressure should not exceed 1.6 MPa, in order to ensure the safety of the testing process. .
A leak test is a test that uses gas as the testing medium; at the design pressure, it employs foaming agents, colorants, gas molecule sensors, or other methods to detect leak points in the piping system. (1) Pipelines transporting extremely and highly hazardous media as well as flammable media must undergo leak testing. (2) The leak test should be conducted after the pressure test is successful, and air is preferably used as the testing medium. (3) The test pressure for leakage testing is the design pressure. (4) The leak test can be carried out simultaneously with the commissioning test. (5) The leakage test should be conducted by gradually increasing the pressure step by step. Once the test pressure is reached, and after holding that pressure for 10 minutes, a neutral foaming agent should be applied to thoroughly inspect all sealing points such as the valve stuffing boxes, flange or threaded connections, drain valves, exhaust valves, and drain-off valves for any signs of leakage.
My question wasn’t very clear. What I meant was: Can setting the leakage test pressure at or well above 1.6 MPa ensure the safety of the testing process? After all, it’s air pressure; otherwise, there wouldn’t be a requirement during strength tests that the air pressure must not exceed 1.6 MPa. I wonder if you understand what I mean