What safety feature is essential for preventing backflow in a fuel gas system?

In a fuel gas system, a backflow preventer is essential for ensuring that gas flows in only one direction, which helps prevent the return of gas into the supply line. This is particularly important to avoid contamination of the gas supply and to protect the integrity of the system. Backflow can occur if there is a change in pressure, potentially allowing unwanted gases or contaminants to enter the system, leading to safety hazards.

The backflow preventer functions by using a mechanical device that closes off flow if it detects reverse flow conditions. This mechanism is critical in maintaining the safety and reliability of fuel gas systems.

Other features such as a pressure relief valve are designed to relieve excess pressure, a temperature control valve is intended for managing heat levels within the system, and a flow meter measures the volume of gas flowing through the system. While these components are important for the overall function and safety of the gas system, they do not specifically address the issue of backflow, making the backflow preventer the essential safety feature for that purpose.