Which type of valve is typically the first on the discharge side of a pump?

• A. Gate
• B. Check
• C. Ball
• D. Butterfly

Answer: (B)

In a pump system, preventing reverse flow is essential, so the valve right after the pump is typically a check valve. A check valve is a one-way device that lets fluid flow out of the pump but automatically closes if flow tries to go backward. This protects the pump and suction line from backflow, reduces the risk of water hammer when the pump stops, and helps maintain the system’s prime and head.

Gate valves, ball valves, and butterfly valves are great for isolation or throttling, but they don’t automatically prevent reverse flow. They require operator action or don’t seal as reliably under reverse pressure, so they aren’t as well suited for the immediate backflow protection that a check valve provides on the discharge side.