This valve is used for water supply and drainage pipelines, installed at the outlet of the water pump to prevent medium backflow and eliminate destructive water hammer, and can effectively reduce the water hammer pressure when the valve is closed, ensuring the operation of the pipeline network. It has the characteristics of light valve disc, large opening, significant energy-saving effect, low fluid resistance, novel design of water hammer elimination mechanism, stable and reliable sealing performance, wear resistance, long service life, smooth operation, no vibration, no noise, etc.