Cast Iron Dual Plate Check Valve

Check valve refers to the opening and closing parts of the circular disc and by its own weight and media pressure generated action to block the media flow back valve. Automatic valve class, also known as check valve, one-way valve, backflow valve or isolation valve. Disc motion is divided into lifting and swing. Lift check valves are similar in construction to globe valves except for the stem that drives the disc. The medium flows in from the inlet end (lower side) and flows out from the outlet end (upper side). Valve is opened when inlet pressure is greater than the sum of disc weight and flow resistance. On the contrary, the valve is closed when the medium flows back. Swing check valves have a disc that is tilted and rotates on its axis and work in a similar way to lift check valves. Check valves are often used as bottom valves in pumping units to prevent the backflow of water. Check valves are combined with globe valves to provide safety isolation. Disadvantages are large resistance, poor sealing when closing.