G2 Gas Fitter Practice Exam

Which pilot must have its flame sensed before gas is admitted to the main burner?

1. Continuous pilot

2. Proved pilot

3. Intermittent pilot

4. Variable pilot

The correct answer is: Proved pilot

The correct answer is based on safety mechanisms in gas appliances. A proved pilot is a pilot light system designed to ensure that the pilot flame is actually lit and functioning properly before any gas is allowed to flow to the main burner. This is crucial for preventing potential hazards, such as gas leaks or explosions, which could occur if the main burner were to be ignited without a reliable ignition source. In a proved pilot system, a flame sensing device, such as a thermocouple or a flame rectification sensor, continuously monitors the pilot flame. If the flame goes out, the sensing device will shut off the gas supply to the main burner, thus preventing the risk of unburned gas accumulating in the appliance. This safety feature is an essential part of gas safety regulations and helps ensure the safe operation of gas-fired equipment. Other types of pilots, like continuous and intermittent pilots, may have different operational characteristics but often do not provide the same level of proof of flame during operation. Variable pilots may change intensity and are typically more related to specific applications, which do not inherently require flame proofing in the same way as a proved pilot system does. Understanding the nuances of these pilot systems is key to effective and safe gas fitting practices.