Hydraulic control valve is a medium pressure pipeline itself as a power source, hydraulic control valve to open and close, regulating, the leading small pipe valves and different combinations of system, hydraulic control valve can have a nearly 30 kinds of features, the hydraulic control valve is gradually more widespread use. Hydraulic control valve as a control object by pressure changes in water levels and movement, hydraulic control valve can be used alone or several in combination, the hydraulic control valve to allow access to the water main valve and water pressure and flow regulation, individually or combined function. Hydraulic control valve its pressure loss is much greater than the other valves, hydraulic control valves and more loss coefficient of each opening and full closure close to the more dramatic increase in the hydraulic control valve valve diameter the greater the more remarkable.