What is the maximum allowable test pressure for hydrostatic test gauges?

The maximum allowable test pressure for hydrostatic test gauges is 200% of the test pressure. This standard is in place to ensure safety and reliability during testing. Hydrostatic tests are performed to verify the integrity of pressure vessels, pipes, and other equipment that will be subjected to high pressures. By allowing test gauges to withstand pressures up to 200% of the intended test pressure, it ensures that they can effectively monitor and reflect the actual pressure conditions within the system without risking failure or damage.

The rationale for this percentage is grounded in the need for a safety margin. In a hydrostatic test, a liquid is used to fill the system, and then the pressure is increased to verify there are no leaks or weaknesses in the material. A gauge rated at 200% provides a buffer against any unexpected fluctuations, ensuring that it can accurately measure the test conditions without being compromised.

This allows QA professionals to ensure that the equipment operates safely under normal conditions as well. Thus, the choice of 200% reflects industry standards for ensuring both the functionality and safety of the equipment being tested.