Check valve: A valve that automatically prevents fluid from flowing backwards. The valve flap of the check valve is opened by fluid pressure, and the fluid flows from the inlet side to the outlet side. When the inlet side pressure is lower than the outlet side, the valve flap automatically closes under the influence of fluid pressure difference, its own gravity and the like to prevent the fluid from flowing backward. Check valves: generally divided into lift type, swing type, butterfly type and diaphragm type.

The check valve refers to a valve that automatically opens and closes the valve flap by means of the flow of the medium itself, and is used to prevent the back flow of the medium, which is also called a check valve, a check valve, a reverse flow valve, and a back pressure valve. The check valve is an automatic valve whose main function is to prevent backflow of the medium, prevent the pump and drive motor from reversing, and discharge the container medium. The check valve can also be used to supply a line in which the pressure may rise to an auxiliary system that exceeds the system pressure.

Common faults in check valves

1 The valve flap is broken; 2 The medium is reversed. The cause of the valve flap breaking is that the medium pressure is close to equilibrium before and after the check valve, and they are "sawed" with each other. The flap is often tapped with the valve seat.