Which statement is true regarding the operation of a safety valve?

The correct statement regarding the operation of a safety valve is that it must hold the pilot open after ignition, and this is essential for proper functionality in gas appliances. A safety valve is a critical component that ensures the continuous flow of gas to the pilot light once ignition has occurred. This function is vital for maintaining a stable flame, which is necessary for safe operation.

When the pilot is lit, the safety valve allows gas to flow to keep the pilot light burning. If the flame goes out for any reason, the safety valve is designed to close off the gas supply quickly to prevent dangerous leaks, thereby enhancing safety. Holding the pilot open ensures that the appliance can operate safely and effectively while preventing hazardous situations.

Other statements do not accurately reflect the nature or requirements of safety valve operation. For instance, safety valves do not always require manual reset mechanisms, and many reset automatically when the issue that caused them to shut off has been resolved. Additionally, a safety valve is designed to fail closed rather than open to maintain safety by preventing gas leaks. Therefore, the requirement that a safety valve must hold the pilot open after ignition is crucial for the safe operation of gas appliances.