Made up of main valve and adjusting valve and connection system, valve body is straight, main valve control room is diaphragm-type or piston-type double-control room structure, one more control room than general, improve the control function of valve, ensure slowly open、total open、slowly close、cut-off, achieve multifunctional control of pump with one valve、primary regulation

The connect system controlled by adjusting valve, by setting the opening of adjusting valve, can easily achieve all control parameters, like speed of opening、slowly closing

Working principle

When pump start working, valve plate and control room under the pressure of water, main valve is opened by pressure, water is exhausted to exit through adjusting valve B, main valve open slowly.

Set the opening of adjusting valve, can get suitable opening speed of main valve,. When pump stop working, pressure of water of inlet get down quickly, under the action of self-weight、pressure of spring, close most of the opening quickly.

Set the opening and opening ratio, then can get suitable speed of valve opening and closing