The emptying check valve is installed on the outlet pipeline of the high-pressure feed water pump of the thermal power unit to prevent the backflow of the feed water and protect the feed pump. The valve works with the pump minimum flow automatic recirculation side valve, when the feed pump is in a low load or the outlet door is closed, the automatic recirculation bypass valve should be in the open position to ensure the safe operation of the pump. The recirculation bypass valve closes automatically when the empty check valve is opened.