What Is the Working Principle of Directional Check Valve?

As we all know, check valve is an essential item in industrial facilities. Many people may have heard of check valve, but know very little about it. So what is the working principle of directional check valve? What are the functions of directional check valve?

Understanding of directional check valve

Directional check valve, also known as check valve or non-return valve, is used in hydraulic systems to prevent oil flow from reversing or in pneumatic systems to prevent compressed air from flowing in reverse. The fluid can only flow along the inlet, while the outlet medium cannot flow back, commonly known as directional check valve. The directional check valve has two types: straight-through type and right-angle type. The straight-through directional check valve is installed in the pipeline with threaded connection. The right-angle directional check valve has three forms of threaded connection, plate connection and flange connection.

Working principle of directional check valve

The quality inside the directional check valve flows in one direction, preventing reverse flow. Usually, the valve works automatically. When the valve flap opens under the pressure of the fluid flowing in one direction, the valve flap coincides with the valve seat by the fluid pressure and weight of the valve flap, thus cutting off the flow. For example, when the air compressor is used to fill the air tank, a directional check valve should be installed between the air compressor and the air tank to prevent the return of air from the tank to the compressor when the compressor stops.

Functions of directional check valve

• Installing directional check valve at the outlet of the pump can avoid damage to the oil pump due to pressure rise, thus playing the role of check valve. If the directional check valve is installed in parallel with the pressure reducing valve, it can play the role of forward deceleration and reverse acceleration.

• In addition, directional check valve can be connected in series with pressure valve. After series connection, pressure can be adjusted and increased to avoid pressure reverse action. If it is a hydraulic control directional check valve, the directional check valve can be opened by controlling the oil circuit, so that the oil can flow in reverse.
  

• However, in the process of using directional check valve, it is necessary to ensure that the control pressure of hydraulic control directional check valve is sufficient, and control pressure failure should never occur. It is also necessary to check whether the control pressure is consistent with the requirements of directional check valve reverse start, otherwise it is easy to cause directional check valve to fail.