Nozzle check valve, also known as silent check valve, is a special check valve. If there is a high risk of backflow in the power plant, this valve is required, and the nozzle check valve can respond quickly to closure. The design of nozzle check valve minimizes water hammer and vibration caused by medium. Nozzle check valves are particularly suitable for drinking water sanitation systems, watersheds and rivers. It prevents water from flowing back downstream.