Check valve type description

Check valve according to the structure of check valve types can be divided into lifting type check valve, swing check valve, double disc butterfly check valve and axial flow check valve.Lifting type check valve can be divided into straight channel, vertical structure, Angle channel three.Swing check valve is divided into single - disc, double - disc and multi - disc type of three.Butterfly check valve for straight through type.In the form of connection can be divided into thread connection, flange connection, clamping connection and welding connection four.

The disc of the lifting check valve resembles a piston, so it is also called "piston check valve".At the beginning of the flow, it is pushed by the upstream fluid to release the seat and open the flow passage.When flow stops, disc returns to seat under gravity to intercept backflow.Ball check valve disc for ball, its principle is similar to the lifting check valve.

The disc of swing check valves rotates away from the seat to allow forward flow, and when upstream flow stops, the disc returns to the seat to seal, preventing reverse flow.

In the double butterfly check valve, by the middle of the pin shaft connected to the two half valve disc closure, when the upstream flow stops, under the drive of the spring, the two valve disc like butterfly wings quickly closed;As the upstream flow begins, the discs fold backward like butterfly wings and the valve opens, giving the "butterfly shape" its name.