What is the function of a pressure relief device?

• A. A device actuated by inlet pressure and designed to open during an emergency or abnormal condition to prevent a rise of internal pressure in excess of a specified value.
• B. A valve that throttles flow to maintain discharge pressure during pumping.
• C. A sensor that monitors fuel temperature.
• D. A mechanism that seals the pump housing.

Answer: (A)

Pressure relief devices protect the system from overpressure by venting fluid when the pressure reaches a defined limit. They are triggered by inlet pressure and are designed to open during emergencies or abnormal conditions to prevent the internal pressure from rising above a safe, specified value. This safety function keeps hoses, fittings, and components from failing due to excessive pressure. It’s not about throttling to maintain discharge pressure, not a temperature sensor, and not a seal for the pump housing.