Check valve refers to the flow of the media itself and automatically open, close the disc, used to prevent the backflow of the valve, also known as the reverse valve, check valves, countercurrent valve, and back pressure valve. Check valve belongs to an automatic valve, its main role is to prevent the backflow of the media, prevent the pump and drive motor reversal, as well as the container media release.Check Valve
Structure: Check valve: According to the structure, can be divided into lifting type check valve, swing check valve and butterfly check valve three kinds. Lift check valve can be divided into vertical and straight-through two types. The Swing check valve is divided into single, double and multiple three kinds. Butterfly check valve is divided into butterfly-type double, butterfly-type single, the above several check valves in the form of connection can be divided into threaded connection, flange connection, welding and clamp-type connection four kinds. Installation of check valve should be noted in the following matters: 1, in the piping system do not allow the check valve to bear the weight, large check valve should be independent support, so that it is not affected by the pressure caused by piping system. 2, installation attention to the direction of the flow of the medium should be consistent with the direction of the valve body marked arrows. 3, Lift vertical valve Check valves should be installed on the vertical pipe. 4, the lift type horizontal valve check valve should install on the horizontal pipeline.Check Valve
The structure of the lift check valve is similar to that of the cut-off valve, and its disc moves along the midline of the channel, which is reliable, but the fluid resistance is larger, and it is suitable for the small caliber occasions. Lift type check valve can be divided into straight-through and vertical two kinds. Straight-through type lift check valve can only be installed in the horizontal pipe, and vertical lift check valve is generally installed in the vertical pipe.
The disc of the swing check valve rotates on the rotating shaft. Its fluid resistance is generally smaller than the lift type check valve, which is suitable for large caliber occasions. Swing Check Valve According to the number of disc can be divided into single disc swing type, double disc swing type and multiple-disc swing three kinds. Single-disc swing check valves are generally suitable for medium caliber occasions. In order to reduce water hammer pressure, it is best to adopt a closed check valve which can reduce the pressure of water hammer when selecting single disc swing check valve in large diameter pipe. Double-flap Swing check valve is suitable for Judachon caliber pipe. The pair of double disc swing check valve has small structure and light weight, and it is a fast developing check valve. Multi-disc Swing check valve is suitable for large diameter pipeline.Check Valve