A Check Valve is a valve that automatically opens and closes the valve disc by the flow of the medium itself to prevent the medium from flowing back. It is also called a non-return valve, a one-way valve, a reverse flow valve or a back pressure valve. A check valve belongs to the category of automatic valves. Its main function is to prevent the medium from flowing back, to prevent the pump and the drive motor from reversing, and to release the container medium. In addition, the check valve can also be used on the pipeline that provides supply to the auxiliary system where the pressure may rise to exceed the system pressure.
Working principle of check valve
The opening and closing part of the check valve is a circular valve disc, which acts by the flow pressure of the medium itself and the deadweight of the valve disc to block the backflow of the medium. When the medium flows in from the inlet end, the valve disc is pushed open and the medium can pass smoothly; when the medium flows back, the valve disc closes by deadweight and flow resistance to prevent the medium from flowing back.
Classification of check valves
Check valves can be divided into the following categories according to their structure and installation method:
Lift check valve:
The valve disc slides along the vertical center line of the valve body, suitable for horizontal pipelines, and has a large fluid resistance.
Swing check valve:
The valve disc is disc-shaped and rotates around the rotating shaft of the valve seat channel. The flow resistance is small and it is suitable for large-diameter occasions with low flow rate and infrequent flow changes.
Wafer check valve:
The valve disc rotates around the pin shaft in the valve seat. It has a simple structure and can only be installed on horizontal pipes. The sealing performance is poor.
Pipeline check valve:
The valve disc slides along the center line of the valve body. It has a small size, light weight and good processing technology.
Compression check valve:
It has the comprehensive functions of a lifting check valve and a stop valve or an angle valve.
Application scenarios
Check valves are widely used in various occasions where it is necessary to prevent the backflow of media, such as the bottom valve of a pumping device, the outlet of a pump, and the discharge system of a container medium. Due to its automatic opening and closing characteristics, the check valve can effectively prevent the backflow of media in these occasions and protect the normal operation of equipment and systems.
Post time: Mar-05-2025