G2 Gas Fitter Practice Exam

Which term describes the temperature at which a gas ignites?

1. Flash point

2. Fire point

3. Auto-ignition temperature

4. Spontaneous combustion

The correct answer is: Auto-ignition temperature

The term that describes the temperature at which a gas ignites without an external ignition source is known as auto-ignition temperature. This temperature represents the point at which a combustible gas can ignite solely due to the heat present in the environment, without needing a spark or flame. Understanding this concept is crucial for gas fitters, as it helps ensure safe handling and storage of gases. Knowing the auto-ignition temperature of specific gases allows professionals to create safe environments by maintaining temperatures below this threshold, thereby preventing accidental ignition. In contrast, the other terms have distinct definitions: the flash point refers to the lowest temperature at which a liquid produces enough vapor to form an ignitable mixture in air when an ignition source is present. The fire point is similar but represents the temperature at which a liquid produces enough vapor to sustain combustion. Spontaneous combustion involves a material igniting without external heat or ignition source under specific conditions but is not typically associated with the ignition temperatures of gases. Each of these terms plays a different role in fire safety and gas handling but does not specifically describe the phenomena of gases igniting solely due to temperature.