The 705x multi-function pump control valve (also known as JD745X control valve) is a double chamber control diaphragm type hydraulic operation mode, which is installed at the outlet of Shuijing in the water supply and drainage system. The slow opening and quick closing pump control valve is mainly used for slow opening, quick check and slow closing. Ensure that the water pump starts quickly under low pressure. When the pump stops, the valve senses the change of water flow rate, closes 90% quickly and closes 10% slowly, so as to reduce the water hammer and protect the pipeline and water pump. Filter must be installed in front of the valve.

Pressure rating: PN10, PN16, PN25

Zui high working pressure: 1.0MPa, 1.6Mpa, 2.5MPa

Test pressure: 1.1MPa, 1.76Mpa, 2.75mpa

Body pressure: 1.5MPa, 2.4Mpa, 3.75mpa

图A：水泵启动后，下控制腔由进口端补水至下控制腔，推动阀芯向上运动，上控制腔的水通过针阀排出至出口，由于针阀NV1的节流作用，阀门缓慢开启，针阀可根据情况调节，以满足闭闸启动的需要。	图B：水泵正常运转后，阀门继续打开至全开。	图C：阀门全开

图D：水泵停止后，阀盘在感应弹及及水流作用下迅速关闭至90%，被阀杆上螺母挡住，以减小回流水锤，并留出缩口以泄放真空水锤。	图E：出口端高压水通过针阀NV2进入上控制腔，下控制腔的水通过BV流入进口端，针阀可以调节缓闭时间，以减小冰锤，阀门逐渐关闭至初始状态，等待下一次开泵。

→ flow direction

CV check valve

NV needle valve

Bv ball valve