Shinjo Valves-Dual Plate Check Valve, Material GG 25, WCB, SS 304 / 316 Dual Plate Check Valves uses butt-installation and is used in the pipeline or on the pump outlet to, as a safety device, prevents the pump from inversed running due to the different water hammer's shock caused by the medium's back-flow in the pipeline when the pump stops. And it features by small volume, light weight, easy installation and maintenance, set with a guide device, flexible and quick close, preventing of huge medium's back-flow differential and forming silencing effect. Suitable for the pipeline of water supply and drainage, warming etc. or the pump outlet to prevent both pump and pipeline from being damaged due to the medium's back-flow and water hammer's shock.