CB/T3478-1992 Suction check valve 

Check Valve mainly prevents the impact of high-pressure water backflow on the pump impeller in the water supply system of the pump. During the operation of the Stainless Steel Check Valve System, for some reason, when the water pump stops suddenly, the pressure in the pump disappears, and the high-pressure water connected to the pump outlet will flow back to the water pump in reverse. When the pump outlet is equipped with a Stop Check Valve, it will be immediately closed to prevent the high-pressure water from flowing back to the water pump in reverse. If the pump outlet is not equipped with a Cast Steel Globe Stop Check Valve, the high-pressure water will flow back to the water pump in reverse, and the pump impeller will reverse under the impact of high-pressure water. The impeller will be loosened or damaged due to the impact load of high-pressure water. When the pump runs again, the impeller may fly out, posing a great threat to safety production.