What should be done with the safety valves during a hydrostatic test?

During a hydrostatic test, safety valves play an important role in ensuring the integrity of the system being tested. Holding the safety valves to their seat with a testing clamp is critical because it prevents them from opening during the test. If the valves were to open inadvertently, it could lead to a loss of test pressure, which would compromise the purpose of the test and potentially create unsafe conditions.

By keeping the safety valves clamped to their seat, the test can accurately assess the strength and integrity of the piping or equipment under pressure. This procedure helps ensure that the system can handle operational pressures safely, thus protecting personnel and property. It also allows for the verification that the safety valves will function properly once the system is returned to service, as they will be subjected to the conditions they are designed to manage.

In contrast, removing the safety valves for inspection, replacing them entirely, or disassembling them could increase the chances of introducing leaks or other issues, or simply make it impractical to conduct the hydrostatic test effectively. Therefore, the best practice, as stated, is to secure the valves in place to ensure the test runs safely and as intended.