Working Principle of The Check Valve

The check valve can be used on the line to supply the auxiliary system in which the pressure may rise above the system pressure.

The function of this type of valve is to allow the medium to flow in one direction only and prevent the flow in the opposite direction. Usually, the valve works automatically. Under the action of fluid pressure flowing in one direction, the valve disc opens; when the fluid flows in the opposite direction, the fluid pressure and the self-weight of the valve disc act on the valve seat to cut off the flow.

The check valve can be divided into a swing check valve (rotating according to the centre of gravity) and lift check valve (moving along the axis).

The swing check valve has a hinge mechanism, and a disc-like door freely rests on the inclined seat surface. To ensure that the valve clack can reach the proper position of the seat surface every time, the valve clack is designed in the hinge mechanism, so that the valve clack has enough swing space, and makes the valve clack truly and comprehensively contact with the seat. The valve flap can be made of all metal or inlaid with leather, rubber or synthetic coverage on the metal, which depends on the requirements of service performance. When the swing check valve is fully open, the fluid pressure is almost unimpeded, so the pressure drop through the valve is relatively small.

The disc of the lift check valve is located on the sealing surface of the valve seat on the valve body. Except that the valve disc can be lifted freely, the rest of the valve is like a globe valve. The fluid pressure makes the valve disc lift from the sealing surface of the valve seat, and the backflow of the medium causes the valve disc to fall back to the valve seat and cut off the flow. According to the service conditions, the valve disc can be of all-metal structure or inlaid with a rubber pad or rubber ring on the valve disc frame. Like the stop valve, the passage of fluid through the lift check valve is narrow, so the pressure drop through the lift check valve is larger than that of the swing check valve, and the flow of the swing check valve is limited rarely.

China check valve, please select Zeco Valve Group Co., Ltd!