Opening and closing of check valve: the opening and closing part is a circular valve disc, which acts by its own weight and medium pressure to block the backflow of medium.

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, the valve is closed when the medium flows back. Swing check valve has an inclined disc that can rotate around the shaft, and 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 stop valve and stop valve can play the role of safety isolation. The disadvantage is high resistance and poor sealing when closing.

Extended data:

According to the structure, check valves can be divided into lift check valves, swing check valves and butterfly check valves:

1. Lift check valves are divided into vertical and horizontal types.

2. Swing check valves are divided into single disc type, double disc type and multi disc type.

3. Butterfly check valves are straight through type.

The above check valves can be divided into threaded connection, flange connection, welding connection and wafer connection.