What does NFPA 54 state about appliances and equipment that are not part of the test?

NFPA 54, which is the National Fuel Gas Code, outlines several safety and technical requirements for gas piping systems and appliances. The correct assertion regarding appliances and equipment that are not part of the test is that they must be disconnected or isolated from the piping. This is essential to ensure that the test results accurately reflect the integrity and performance of the gas piping system without interference from other connected appliances or equipment.

When appliances are connected during a pressure test, they could potentially lead to false readings, as any leaks in those appliances would not indicate the condition of the piping itself. Thus, isolating or disconnecting them ensures a clear assessment of the gas piping's integrity and allows for effective verification of compliance with safety standards.

While some appliances might influence test results, labeling them clearly, or testing them in conjunction with the piping, do not align with the primary objective of ensuring an accurate assessment of the gas piping integrity. Therefore, the directive to disconnect or isolate non-tested appliances is crucial for maintaining the reliability of the test results and ensuring a safe installation.