What does a pressure test verify in a gas system?

A pressure test in a gas system is primarily designed to verify the gastight integrity of gas piping. This process involves checking for leaks in the piping that can occur due to improper installation, material degradation, or other factors that compromise the piping's ability to safely contain gas under pressure.

By performing a pressure test, technicians can ensure that all joints, connections, and the piping system as a whole are sealed properly and capable of withstanding the operational pressures without leaking. This is crucial for safety, as leaks can pose significant risks of fire, explosion, or exposure to hazardous gases.

The other options, while related to gas systems, do not accurately describe the purpose of a pressure test. Monitoring the pressure level of gas in an appliance pertains more to operational functionality rather than integrity testing. Evaluating burner efficiency relates to how well a burner performs its job, which is unrelated to the physical structure of the gas piping. Lastly, temperature measurements of gas do not fall within the scope of what a pressure test aims to assess, as pressure and temperature are separate parameters affecting gas behavior.