When starting a turbine driven boiler feed pump, care should be taken to insure that the recirculating valve is open. Which of the following valves should be closed when starting?

Correct Answer: Option D — Pump discharge valve

Centrifugal boiler feed pumps must be started against a closed discharge valve to minimize starting torque and motor or turbine overload. The recirculation line must remain open to prevent rapid water vaporization and catastrophic overheating inside the pump casing due to churning.