Which device is designed to automatically lower system pressure to a desired level?

• A. Flow Control Valve
• B. Gate Valve
• C. Pressure Reducing Valve
• D. Check Valve

Answer: (C)

Automatic pressure regulation is what this item tests. A Pressure Reducing Valve is designed to automatically hold the downstream system pressure at a selected value, regardless of fluctuations in supply pressure or flow within its operating range. It uses a sensing element and a spring-loaded mechanism to modulate flow and keep the set pressure on the downstream side. When demand would push the downstream pressure up, the valve throttles to limit it; when demand drops, it opens more to maintain the desired level. This protects piping and equipment from over-pressurization and helps ensure the fire protection system operates reliably. The other devices don’t regulate pressure automatically: a flow control valve adjusts flow, a gate valve is a manual shut-off, and a check valve prevents backflow without setting a fixed downstream pressure.