Check valve principle check valve structure check valve features check valve application check valve construction

Check valve is also known as one-way valve or check valve Its function is to prevent the backflow of medium in the pipeline The opening and closing parts automatically open or close by the medium flow and force, so as to prevent the backflow of medium The valve is called check valve The check valve belongs to the automatic valve category, which is mainly used on the pipeline with one-way flow of medium It only allows the medium to flow in one direction to prevent accidents According to the structure, the check valve can be divided into lift check valve, swing check valve and butterfly check valve Lift check valve can be divided into vertical and horizontal two kinds Swing check valve is divided into three types: single disc, double disc and multi disc Butterfly check valve is straight through type The above check valves can be divided into three types of connection: screw connection, flange connection and welding The structure of the lift check valve is generally similar to that of the stop valve The valve disc moves up and down along the center line of the channel, which is reliable in action, but with large fluid resistance, so it is suitable for small caliber occasions Lift check valve can be straight through type and vertical type The straight lift check valve can only be installed in the horizontal pipeline, while the vertical lift check valve is generally installed in the vertical pipeline The disc of swing check valve rotates around the shaft Its fluid resistance is generally less than that of the lift check valve, which is suitable for large caliber occasions The swing check valve can be divided into three types according to the number of discs: single disc swing, double disc swing and multi disc swing Single disc swing check valve is generally suitable for medium caliber applications When single swing check valve is used for large diameter pipeline, in order to reduce water hammer pressure, Zui should use slow closing check valve which can reduce water hammer pressure Double disc swing check valve is suitable for large and medium diameter pipeline Double disc swing check valve is a kind of fast developing check valve with small structure and light weight Multi disc swing check valve is suitable for large diameter pipeline The structure of butterfly check valve is similar to butterfly valve Its structure is simple, flow resistance is small, and water hammer pressure is also small The installation of check valve shall pay attention to the following matters: 1 Do not make the check valve bear the weight in the pipeline, and large check valve shall be independently supported, so that it is not affected by the pressure generated by the pipeline system 2 During installation, the direction of medium flow shall be consistent with the direction of arrow on the valve body 3 Lift type vertical disc check valve shall be installed on the vertical pipeline 4 Lift type horizontal disc check valve shall be installed on horizontal pipeline.