300X slow-closure check valve is an intelligent valve installed at the pump outlet of high buildings water supply system and other water supply systems to prevent media from flowing back and phenomena of water hammer and water hitting. The valve even possesses functions of electric valve, check valve and water hammer eliminator, which can effectively improve the safety and reliability of the water supply system.It also integrates the technological principles of slow opening, quick closing and slow closing to eliminate water hammer, in order to prevent generating water hammer of opening the pump and water hammer of stopping the pump. The valve can switch automatically in accordance with the rules of pumps as long as you operate switch button on the pump motor, with large flow and small pressure loss. It is applicable to valves of less than DN600mm.