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HomeNewsWorking principle and classification of check valve

Working principle and classification of check valve

Check Valve is a kind of valve whose opening and closing parts are round disc, and its action is produced by its own weight and medium pressure to block medium backflow. Belong to automatic valve class, also known as check valve, one-way valve, return valve or isolation valve. Disc movement is divided into lifting type and swing type. Lift check valve is similar to Globe Valve in structure, only lack of stem to drive disc. 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 disc weight and its flow resistance, the valve is opened. On the contrary, the valve will be closed when the medium flows back. The Swing Check Valve has an inclined disc which can rotate around the shaft. Its working principle is similar to that of the lift check valve. Check valve is often used as the bottom valve of pumping device, which can prevent the backflow of water. Combined use of check valve and stop valve can play the role of safety isolation. The disadvantages are high resistance and poor sealing when closing.

working principle

The check valve can also be used to supply the auxiliary system whose pressure may rise above the system pressure. Check valve can be divided into swing check valve (rotating according to the center of gravity) and lift check valve (moving along the axis).

Check valve the function of this type of valve is to only allow the medium to flow in one direction and prevent the flow in the opposite direction. Usually, this kind of 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 dead weight of the valve disc act on the valve seat, thus cutting off the flow.

Check valve belongs to this type of valve, which includes swing check valve and lift check valve. The swing check valve has a hinge mechanism and a gate like disc which is free to lean against the inclined seat surface. In order to ensure that the valve disc can reach the proper position of the seat surface every time, the valve disc is designed in the hinge mechanism, so that the valve disc has enough swing space, and makes the valve disc truly and comprehensively contact with the seat. The valve disc can be made of metal, or inlaid with leather, rubber or synthetic cover, depending on the performance requirements. When the swing check valve is fully opened, 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. In addition to the valve disc can rise and fall freely, the rest of the valve is just like the stop valve. The fluid pressure makes the valve disc lift from the sealing surface of the valve seat, and the medium backflow causes the valve disc to fall back to the valve seat and cut off the flow. According to the conditions of use, the disc can be of all metal structure, or it can be inlaid with rubber pad or rubber ring on the disc holder. Like globe valve, the passage of fluid through lift check valve is narrow, so the pressure drop through lift check valve is larger than that of swing check valve, and the flow of swing check valve is less limited.


Open and close by the force of the medium flow to open or close, in order to prevent the medium backflow of the valve called check valve. Check valve is an automatic valve, which is mainly used in the pipeline with one-way flow of medium. It only allows the medium to flow in one direction to prevent accidents.

Structure classification

According to the structure, it can be divided into lift check valve, swing check valve and butterfly check valve

1. Lift check valve is divided into vertical and horizontal.

2. Swing check valve is divided into three types: single valve, double valve and multi valve.

3. Butterfly check valve is straight through type.

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

Material classification

1. Cast iron check valve

2. Brass check valve

3. Stainless Steel Check Valve

4. Carbon Steel Check Valve

5. Forged steel check valve

Ningbo RMI Plastic Co.,Ltd
Business Type:Manufacturer
Product Range:Valves , Pipe Fittings , Pipe Fittings
Products/Service:PVC PP PVDF Diaphragm Valve , PP PVC Butterfly Valve , Plastic Valve , PVC Pipe Fitting , PVC check valve , PVC Ball Valve
Company Address:No.731 Mingzhou Road,Xinqi Street,Beilun Dist, Ningbo, Zhejiang, China

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