Lift check valve structure

Lift check valve refers to the valve that automatically opens and closes the disc depending on the flow of the medium itself, which is used to prevent the backflow of the medium It is also called check valve, check valve, backflow valve and back pressure valve The check valve belongs to an automatic valve, whose main function is to prevent medium backflow, reverse rotation of pump and drive motor, and discharge of container medium The check valve can also be used in the line that supplies the auxiliary system with the pressure that may rise above the system pressure The check valve can be divided into swing check valve (rotating according to the center of gravity) and lift check valve (moving along the axis) Principle structure during the use of the valve, the medium flows in the direction of arrow as shown in the figure 1 When the medium flows in the specified direction, the valve disc is affected by the medium force When the medium is opened, the valve disc is closed due to the self weight of the valve disc and the effect of the medium reverse force on the valve disc, making the sealing surface of the valve disc and the valve seat close, so as to prevent the medium reverse flow 2 The sealing surface of valve body and valve disc shall be welded with stainless steel 3 The structural length of the valve shall be in accordance with gb12221-1989, and the flange connection size shall be in accordance with JB / t79-1994 Installation and maintenance 1, both ends of the valve passage must be blocked, and there is a dry and ventilated room If it is stored for a long time, it is necessary to check the anti rust corrosion frequently 2 Before installation, the valve shall be cleaned and defects caused during transportation shall be eliminated 3 During installation, it is necessary to carefully check whether the mark and nameplate on the valve meet the use requirements 4 Lift type vertical disc check valve shall be installed on horizontal pipeline 5 The lift horizontal disc check valve shall be installed on the vertical pipeline 6 Do not make the check valve bear the weight in the pipeline, and the large check valve should be supported independently, so that it is not affected by the pressure produced by the pipeline system 7 When installing the check valve, pay special attention to the flow direction of the medium, make the normal flow direction of the medium consistent with the arrow direction indicated on the valve body, otherwise the normal flow of the medium will be cut off The bottom valve shall be installed at the bottom end of the water pump suction pipeline 8 The through lift check valve shall be installed on the horizontal pipeline, while the vertical lift check valve and bottom valve shall be generally installed on the vertical pipeline, and the medium shall flow from bottom to top 9 When the check valve is closed, water hammer pressure will be generated in the pipeline, which will cause damage to the valve, pipeline or equipment in serious cases, especially for the large mouth pipeline or high-pressure pipeline, so highly attention shall be paid to the selection of the check valve.