缓闭式止回阀一般分为隔膜阀和活塞阀两大类，本公司生产的缓闭式止回阀口径在DN500mm以下者采用隔膜型，口径在DN600mm以上者采用活塞型，两者之动作原理类似。缓闭式止回阀具有开启和关闭速度调控和逆止功能，阀门安装能有效控制水泵在启动与停止转动时会自动调节到***开启和关闭的速度。广泛适用于工业给水、高层建筑由水泵直接给水系统中，有效减少水锤及水击现象产生，达到安全关闭效果。

Dashpot check valves are usually divided into diaphragm valves and piston valves two categories, the caliber of the  company’s production bellows DN500 using diaphragm type, and DN600 more in the use of piston type, whichever is the principle of similar moves. Dashpot check valve has the function of opening or cutting the speed control and pawl, it can control the water pump availably when the water pump is opening and stopping, the valve will regulate the speed of opening or closing automatically to the best state. It is widely used in the system whose water is supplied by the water pump, such as the industrial water supply、tall building water supply, effectively reduce the times of the water hammer and water beat, up to the safely effect of the closure.