precision flow control valve is the pipeline medium pressure as the driving force, the opening and closing, regulating the valve. It consists of a main valve and attached pipe, needle valve, ball valve and pressure gauge and other components, according to the purpose of use, different functional sites, can be transformed into remote control float valve, pressure reducing valve, slow closing check valve, flow control valve , Pressure relief valve, hydraulic electric control valve, emergency shut-off valve. The pilot valve with the media level and pressure changes and action, due to a large number of pilot valves, can be used alone or in several combinations, you can make the main valve to the water level and water pressure and flow, etc. to separate and complex adjustment function The But the main valve body similar to the valve, the valve is fully open, the pressure loss is much larger than other valves, and the opening degree of each loss coefficient is close to the closed state, the more the surge, the greater the diameter of the valve Significantly. With the above characteristics of the valve, in the action near the valve to accelerate, prone to the impact of water hammer, close to the full closure, the valve moves the more slowly the better, so the valve can be set on the throttle device. In addition the pilot valve throttle and action part to try to avoid the installation of small diameter openings, so as not to plug. If necessary, add filters, regular maintenance and set the bypass pipe. industrial automation and control valve diaphragm type and piston type two, the same principle, are above the downstream pressure difference as the driving force, a pilot valve control, so that the diaphragm (piston) hydraulic differential operation, completely by the hydraulic automatic adjustment, so that the main The valve flap is fully open or fully closed or in a regulated state. When the pressure water in the control chamber above the diaphragm (piston) is discharged to the atmosphere or downstream low pressure zone, the pressure value acting on the lower part of the valve flap and below the diaphragm is greater than the above pressure value, thereby pushing the main valve valve Open position: When the pressure inside the control chamber above the diaphragm (piston) is in the middle of the inlet pressure and the outlet, the main valve disc is in the regulated state and its adjustment position depends on the combination of the needle valve and the pilot valve in the conduit system Control effect. The pilot valve can open or close its own small valve port by changing the downstream pressure, thus changing the pressure value of the control room above the diaphragm (piston) and controlling the adjustment position of the main valve disc. Can be used for living water supply, fire protection systems and industrial water supply systems.