What is the correct order of parts that follows a pump for the listed components?

• A. Concentric Reducer, Spool, Check Valve, Gate Valve
• B. Spool, Concentric Reducer, Check Valve, Gate Valve
• C. Gate Valve, Spool, Check Valve, Concentric Reducer
• D. Spool, Check Valve, Gate Valve, Concentric Reducer

Answer: (A)

The sequence after a pump is chosen to protect the pump, control flow and backflow, and allow easy shutdowns. Start with a concentric reducer to match the discharge to the downstream piping while keeping the centerline aligned, which minimizes turbulence and wear right at the pump outlet. Next, a spool provides a straight, calm run of pipe so the following devices encounter stable flow rather than a disrupted swirl. The check valve then sits right after that straight run to prevent reverse flow when the pump stops, protecting the pump and reducing the risk of water hammer. Finally, a gate valve is placed at the end to allow isolation of the downstream system for maintenance without compromising the protection provided by the check valve. Putting the valve sequence in a different order can compromise pump protection, increase wear, or make maintenance more difficult.