Control valve: the current production of the control valve is basically a chip combination control valve, the number of pieces and the way of entering and returning can be combined and selected according to the needs; the inlet valve core in the valve is completely sealed with rubber gasket except ZC valve, which has the advantages of strong anti-fouling ability and reliable sealing, and the inlet and return spool adopts hydraulic balance mode, which saves effort in operation and reduces the contact force of the other parts.