Flow control valve, also known as self-operated flow control valve, flow balance valve and static flow control valve, is an intuitive and simple flow control device. Using the flow control valve in the pipe network, the flow can be set directly according to the design. The valve can automatically eliminate the flow deviation caused by residual head and pressure fluctuation under the action of water, and can keep the set flow unchanged no matter how the system pressure changes. These functions of the valve make the flow regulation of the pipe network complete at one time, and turn the pipe network regulation into simple flow distribution, which effectively solves the hydraulic problems of the pipe network.