GB/T586-2015 Cast steel check valve

check valve refers to a valve whose opening and closing parts are circular valve discs and act by their own weight and medium pressure to block the backflow of medium. It is an automatic valve, also known as check valve, one-way valve, return valve or isolation valve. The movement mode of valve disc is divided into lifting type and swing type. The structure of lift check valve is similar to that of stop valve, only lacking the stem to drive the valve disc. The medium flows in from the inlet end (lower side) and out from the outlet end (upper side). When the inlet pressure is greater than the sum of the disc weight and its flow resistance, the valve is opened. On the contrary, when the medium flows back, the valve is closed. Swing check valve has an inclined disc that can rotate around the shaft. Its working principle is similar to that of lift check valve. Check valve is often used as the bottom valve of pumping device, which can prevent the backflow of water. The combination of check valve and stop valve can play the role of safety isolation. The disadvantage is high resistance and poor sealing when closing.