With the OEM to large-scale, high-pressure direction, the required hydraulic components are also positive pressure, high flow hydraulic direction of development. In particular, the demand for remote control components is growing, with proportional pilot valve control valve is the most suitable market control system. QKF6 combined control valve is a new product developed and designed for the working principle of a full hydraulic crane with a new pilot proportional control hydraulic system. It integrates safety valve, pressure relay, accumulator, oil filter, multiple check valves, shuttle valve , Solenoid valves and other hydraulic components, the pilot valve solenoid valve will be pilot oil control valve were passed to the pilot control port, in order to achieve centralized control crane crane centralized control. Is now widely used in 25 ~ 80T new hydraulic crane hydraulic system. Main performance parameters: 1, rated pressure: 3.5MPa; 2, rated flow: 18L / min; 3, the sender sending pressure: 0.6MPa; 4, storage capacity: 0.63L; , Filtration precision 10μm.