Which device adjusts engine speed to control pressure surges?

• A. Throttle
• B. Governor
• C. Regulator
• D. Pressure Governor

Answer: (D)

The ability to adjust engine speed to control pressure surges is provided by a pressure governor. This device continuously senses the discharge (system) pressure and automatically increases or decreases the engine RPM to keep the pressure at a preset setpoint. By modulating engine speed in response to pressure changes, it smooths out fluctuations and reduces water hammer or pressure spikes that can occur during quick demand changes.

A throttle is a manual control that sets engine speed but doesn’t automatically compensate for changes in system pressure. A governor in general controls engine speed, but without pressure feedback it wouldn’t specifically target surge suppression. A regulator typically governs another parameter (like fuel or pressure in a different subsystem) and isn’t the component dedicated to adjusting engine speed to maintain stable pump pressure.