DRVZ (H42X) silence check valve consists of body, seat, flow deflector, valve disc, bearing and springs and other major parts. the internal flow channel uses linear design so that pressure loss is minimal. The stroke of switch of the valve disc is very short. Therefore, it can be shut down quickly without large noise of water hammer,having a feature of silent closure when the pump stops. The valve is mainly used for water supply and drainage system, fire protection system and HVAC system which can be installed at the pump outlet to avoid backflow and water hammer damage to the pump.