What is the role of a pressure relief valve in some fuel systems?

• A. To relieve excess pressure and protect components; can vent to tank or return line.
• B. To reduce fuel temperature.
• C. To regulate air intake.
• D. To store extra fuel.

Answer: (A)

A pressure relief valve serves to keep the fuel system from over-pressurizing. When the system pressure rises above the valve’s set limit, the valve opens and allows fuel to escape either back to the tank or into the return line. This protects components such as pumps, regulators, and hoses from damage and helps prevent issues like leaks or vapor lock, ensuring the system operates safely and consistently. It isn’t involved in cooling fuel, regulating air intake, or storing fuel.