What does PRV stand for in the pressurization system?

• A. Pressure Relief Valve
• B. Passenger Relief Valve
• C. Pressure Regulation Valve
• D. Positive Release Valve

Answer: (A)

PRV stands for Pressure Relief Valve. Its job is to vent cabin air when the pressure difference between the cabin and the outside atmosphere would exceed the system’s designed limit, acting as a safety backstop to prevent overpressurization. It’s a spring-loaded, one‑way valve that opens at a predetermined differential and vents air to the outside; once the pressure drops back into the safe range, it closes again. This protects the aircraft structure and occupants from damage due to too-high cabin pressure, complementing the normal pressure regulation done by the outflow valve and controller. The other terms aren’t standard for this function, and they don’t describe the protective relief role that the PRV provides.