What does governor do in a fire pump system?

• A. It increases flow to the nozzle automatically.
• B. It prevents the engine from operating above idle speed.
• C. It automatically adjusts engine RPM to maintain targeted pump discharge pressure.
• D. It switches between manual and automatic modes.

Answer: (C)

In a fire pump system, the governor is the speed-control device that keeps the pump producing the desired discharge pressure by adjusting the engine RPM based on pressure readings. It uses feedback from the pump discharge pressure: when pressure tends to drop (more flow is needed), the governor increases engine speed to raise the pump head and restore the set pressure; when pressure is high, it reduces RPM to prevent overshoot. This automatic regulation centers on maintaining the targeted discharge pressure, not simply pushing more water to the nozzle or keeping the engine at idle, and it isn’t just about switching modes.