Which of the following is NOT a purpose of check valves?

• A. Stops reverse flow of liquid
• B. Can reduce motor starts & stops
• C. Eliminates motor running backwards
• D. Prevents cavitation in the pump

Answer: (D)

Check valves are placed to stop backflow and protect equipment, keeping fluid moving in the intended direction. They also help avoid unnecessary starts and stops of the pump by preventing reverse flow that could drive the motor or cause flow reversals when the system pressure changes. Cavitation, on the other hand, happens when the pressure in the pump or on the suction side drops low enough for vapor bubbles to form and then collapse, which is a function of suction head, flow rate, and pump design. A discharge-side check valve doesn’t address those suction-side pressure conditions, so it doesn’t prevent cavitation. That’s why preventing cavitation isn’t a purpose of a check valve.