Check valve opening and closing: the opening and closing parts are circular disc, and the action is generated by its own weight and medium pressure to block the reverse flow of medium.

The medium flows in from the inlet end (lower side) and flows 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 will be closed when the medium flows backward. Swing check valve has an inclined disc which 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 stop valve and stop valve can play a 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 valve, swing check valve and butterfly check valve

1. Lifting check valve is divided into vertical and horizontal two kinds.

2. Swing check valve is divided into single valve type, double valve type and multi valve type.

3. Butterfly check valve is straight through type.

The above check valves can be divided into thread connection, flange connection, welding connection and clamp connection.