This valve is applicable to the duckwork of fluid medium, especially auto sprinkler system and various water supply works, to ensure the no-return flowing of medium. As it is provided with special soft sealant and spring anto reset mechanism, It will automatically switch off before the occurrence of water hammer caused by the stop of medium. To avoid the noise brought by water hammer and protect the duckwork and equipment against damage, to meet the demand of works and constructions, we present clamp silencer valve and female thread silencer checker valve, among which the female thread silencer check valve is made of casting copper alloy.