What must be done with appliances not included in a pressure test?

Appliances not included in a pressure test must be disconnected or isolated to ensure safety and compliance with the National Fuel Gas Code. This is necessary because if these appliances are left connected during the pressure test, they can be subjected to pressures that may exceed their design limits, potentially leading to damage, failure, or leaks. Disconnecting or isolating them prevents any risk to the appliances while ensuring that the integrity of the gas piping system is properly assessed without interference from appliances that are not part of the test. This practice promotes a thorough and safe evaluation of the gas system.

In scenarios where appliances remain connected, there is also the risk that any leaks or weaknesses in the system might go undetected, potentially endangering the safety of the installation. By isolating the appliances, it allows for a more accurate pressure test and maintains the overall safety standards required by the code.