What is the risk of a failed check valve on the discharge of a centrifugal pump?

• A. Backflow into the spare pump
• B. Loss of prime in the primary
• C. Overheating of the motor
• D. Increased noise

Answer: (A)

A check valve on the discharge line is there to stop fluid from flowing backward through the pump and into other equipment in the system. If that valve fails, reverse flow can occur and push liquid back toward the standby or spare pump that shares the discharge line. That backflow is the main risk because it can move fluid into the spare pump when it shouldn’t be receiving flow, potentially affecting its operation. The other issues, like motor overheating or more noise, aren’t direct consequences of a discharge check valve failing, and loss of prime in the primary would be a secondary effect that isn’t the primary risk highlighted by a failed discharge check valve.