304. What type of valve is usually installed on the discharge side of a centrifugal cargo pump on a tank vessel to prevent oil from running back to the tanks when the pump shuts down?

A check valve prevents backflow by automatically closing when flow reverses, a critical function for centrifugal cargo pumps to prevent liquid from returning to the tanks upon shutdown. Gate, butterfly, and globe valves are control valves that do not provide this automatic backflow prevention.