Which type of valve is used to prevent backflow in a pump system?

• A. Butterfly valve
• B. Check valve
• C. Gate valve
• D. Pressure relief valve

Answer: (B)

The check valve is specifically designed to prevent backflow in a pump system, ensuring that the fluid flows in only one direction. This is crucial in maintaining system integrity and preventing reverse flow that could potentially damage equipment or disrupt processes.

Check valves operate automatically, relying on the flow of fluid to open and close. When the flow is in the correct direction, the valve opens, allowing the fluid to pass through. If the flow attempts to reverse, the valve closes tight, effectively sealing the system against backflow.

In contrast, although butterfly valves, gate valves, and pressure relief valves serve important functions within systems, they do not primarily function to prevent backflow. Butterfly and gate valves are typically used to start and stop flow, while pressure relief valves are designed to release excess pressure in the system, protecting it from potential damage due to overpressure conditions. This distinction underscores the necessity of employing a check valve in applications where backflow prevention is critical.