Oklahoma Service Technician Practice Exam

The installation of a flame sensor or safety shutoff valve on gas appliances is crucial for maintaining safety. Flame sensors monitor the presence of a flame and ensure that gas is only supplied when there is a flame present to ignite it. This prevents the dangerous accumulation of unburned gas, which could potentially lead to an explosion or fire hazard.

A safety shutoff valve acts as a fail-safe mechanism that automatically shuts off the gas supply if it detects any irregularities, such as a flame going out unexpectedly. This combination of monitoring and automatic shutoff greatly reduces the risks associated with using gas appliances, promoting a safer environment for users.

While thermocouples are also important in gas appliances for temperature regulation and safety, the focus here is on devices that actively prevent gas leaks or hazards, making the flame sensor and safety shutoff valve the correct answer in this context. Other options like pressure relief valves and gas meters serve different purposes related to managing pressure and measuring gas consumption respectively, but do not directly address flame presence or gas safety in the same critical manner.