Control valve: Control the flow, flow direction, pressure of hydraulic oil, the working order of hydraulic actuators and protect the hydraulic circuit. The popular point is to control and adjust the flow direction, pressure and flow of the hydraulic medium. So as to control the direction of movement of the actuator, the output force or torque. Movement speed. Action sequence, as well as limiting and regulating the working pressure of the hydraulic system, preventing overload and other functions (such as check valve, reversing valve, relief valve, pressure reducing valve, sequence valve, throttle valve, speed control valve, etc.