Pressure Test, Check Gas, Gas System Test, Gas Testing, Test Gas, Gas TestWhenever there is someone buying, selling or relocating a home or when they have any repairs, replacements or additions done to their natural gas system, it is a requirement that the gas system must be tested and inspected. A master licensed plumber must pull a gas permit from the local city/parish plumbing authority to test the system. After the test conducted by the master licensed plumber is done, the city plumbing authority sends an inspector to verify that the gas system is in proper working order.