ZLf self operated flow control valve has tested the accuracy of constant flow, and the accuracy of constant flow is ± 3%. The internal materials are all bronze and stainless steel, which no longer requires power supply, saving 8 ~ 30% of coal and electricity respectively. The set flow can be adjusted within 360 °, and the manual control valve group has a unique locking device and flow display to ensure the regulation quality during operation. ZLf self operated flow control valve (self operated flow balance valve) is a valve with special functions. Based on many years of production practice of flow balance valve, our company has newly developed high-precision flow products. The valve belongs to the flow regulation and control device of the whole liquid pipe network. It is an ideal supporting product for the heating and air conditioning system to realize "metering and charging". It effectively solves the imbalance problem of the heating network, so as to overcome large flow, small temperature difference and unreasonable operating conditions.