The valve is used for installing the water supply and drainage pipeline at the outlet of the water pump to prevent the medium from upstream and eliminating the destructive water hammer, and can effectively reduce the water hammer pressure of the valve to ensure the safe operation of the pipeline. It has a lighter valve, open degree, energy-saving effect of significant Department of fluid resistance small water hammer elimination mechanism has the advantages of novel design features stable and reliable sealing performance, abrasion resistance, long service life, stable operation, no vibration, no noise etc..