Feedwater pumps impart high energy caused by flow and pressure to the feedwater passed to the boiler. All centrifugal pumps require a minimum flow rate through the pump to avoid overheating and cavitation. The boiler feedwater recirculation valve controls bypass flow from the pump outlet back to the deaerator or LP drum. This bypass flow prevents overheating and cavitation of the pump. The valve must prevent or withstand cavitation at high pressure drops.