The 700x pump control valve is a backstop valve installed at the outlet of the pump in high-rise buildings and other water supply systems to prevent backflow of the medium. When the pump is about to stop the water supply, the valve first closes about 90% of the curtain to prevent the water hammer and water hammer caused by the sudden stop of the pump: when the pump is completely stopped, the valve is completely closed to prevent the water from flowing back, effectively protecting the pump from the impact of the return flow and causing reversal.