In a standing pressure test, what is the recommended practice regarding the source valve and pressure level?

In a standing pressure test, it is critical to ensure that the system is adequately assessed for leaks and integrity over a sufficient duration under controlled conditions. The recommended practice involves closing the source valve to prevent any additional pressure fluctuations and applying a pressure level that exceeds the normal operating pressure by 20%. This elevated pressure helps to ensure that even minor leaks are detected, as they may not be noticeable at the normal operating pressure. Maintaining this elevated pressure for a full 24 hours allows ample time to observe any pressure drop that could indicate a failure in the system.

This approach not only verifies the integrity of the entire gas line system but also provides a safety margin that accounts for variations in environmental conditions. The decision to use a 20% increase above working pressure is based on standards that take into account the potential for materials to expand or react under sustained pressure, ensuring that safety and effectiveness are prioritized during the testing process.