What type of valve would be fitted with a quarter-turn power actuator, such as a rack- and-pinion?

Correct Answer: Option D — Butterfly valve

Butterfly valves utilize a disc that rotates 90 degrees to open or close the flow path. Because they require only a quarter-turn to move from fully open to fully closed, they are ideally suited for rack-and-pinion or other rotary power actuators commonly found in automated marine piping systems.