How must shut off valves perform under hydrostatic testing?

Shut off valves must undergo hydrostatic testing to ensure they can handle pressures significantly higher than their normal operating conditions. The requirement for them to withstand a test of at least four times the rated service pressure without failure is crucial for safety and integrity. This level of testing helps confirm that the valves can maintain their function and prevent leaks or failures under extreme circumstances, which is essential in applications involving compressed natural gas. By verifying that the valves do not fail at such elevated pressures, operators can have greater confidence in their reliability and safety during actual operations.