What is a vertical lift check valve? 

Vertical lift check valve refers to the valve which automatically opens and closes the valve disc by replying on the flow of the medium itself to prevent the back-flow of the medium, it is also known as one way valve, non return valve, back pressure valve, cut off valve. Check valve is one kind of automatic valve whose main function is to prevent the back-flow of the medium, the reverse rotation of the pump and the driving motor, and the discharge of the medium in the container. 

Check valve can be divided into swing type check valve(rotating according to the center of gravity) and lift type check valve(moving along the axis). the function of this type of check valve is to allow the flow of the medium only in one direction and prevent the medium from flowing in the opposite direction. Usually this kind of check valve works automatically. Under the action of fluid pressure flowing in one direction, the valve plate opens; when the fluid flows in the opposite direction, the fluid pressure and the self-weight of the disc work on the valve disc to close to the valve seat, to cut off the flow.