What Is A Check Valve?

Check valve refers to a valve whose opening and closing part is a circular valve disc, which acts by its own weight and medium pressure to block the backflow of the medium. It is an automatic valve, also known as check valve, one-way valve, return valve or isolation valve. The disc movement mode is divided into lift type and swing type. The lift check valve is similar in structure to the globe valve, except that it lacks the valve stem to drive the disc. The medium flows in from the inlet port (lower side) and flows out from the outlet port (upper side). When the inlet pressure is greater than the sum of disc weight and its flow resistance, the valve is opened. Conversely, the valve is closed when the medium flows backwards. The swing check valve has an oblique disc that can rotate around the axis, and its working principle is similar to that of the lift check valve. The check valve is often used as the bottom valve of the pumping device to prevent the backflow of water. The combination of check valve and globe valve can play the role of safety isolation. The disadvantage is that the resistance is large and the sealing is poor when closed.