G2 Gas Fitter Practice Exam

What is the most important safety step when conducting a pilot turndown test on an appliance with a combination gas valve?

1. Turn off the main burner

2. Close the pilot valve

3. Check the gas pressure

4. Inspect the pilot light

The correct answer is: Close the pilot valve

When conducting a pilot turndown test on an appliance equipped with a combination gas valve, the most important safety step is to close the pilot valve. This action is critical because it prevents any gas from flowing to the pilot light during the test, thereby eliminating the risk of a gas leak or unintended ignition. In this context, closing the pilot valve ensures that the system is in a safe state before any further testing occurs. It secures the appliance by isolating it from the gas supply, allowing the technician to perform the test without being exposed to the dangers associated with an active gas flow. This is a foundational step in ensuring safety when conducting maintenance or testing, as it addresses the immediate risk of gas exposure. Other actions, such as turning off the main burner or checking the gas pressure, may also be necessary steps in the overall maintenance procedure but do not prioritize the immediate safety of the technician during the pilot turndown test. Inspecting the pilot light, while important for confirming its operation, comes after ensuring that gas is not present during the test. Thus, closing the pilot valve stands out as the foremost priority in maintaining safety during this specific procedure.