Flow control valve works: Digital flow control valve its structure is composed of automatic valve spool, manual valve spool and the display part. Display part by the flow valve movement, sensor transmitter, electronic calculator display part. Its job is complicated. Measured water flow through the valve, the flow of water impact flow impeller impeller, impeller rotation and sensor senses, the sensor sends a signal proportional to the flow rate, the flow of electrical signals through the wire into the electronic calculator, through the calculator Calculation, microprocessor processing, the flow value is displayed. Manual spool is used to adjust the flow, according to the display value to set the desired flow value. Automatic spool is used to maintain constant flow, that is, when the pipe network pressure changes, the automatic spool will automatically open the fire under the pressure of small valve port.