Directional valves are directional control valves with more than two flow patterns and two or more ports. Is to achieve the hydraulic oil flow communication, cut off and change, as well as the pressure relief valve and the order of action control. Directional valve pressure shock solution: 1, the use of damping valve with a reversing valve 2, re-make a spool appropriate to reduce the cone angle cone 3, repair valve seat research, replacement ball 4, Grinding the valve hole, re-allocation of slide valve to ensure a reasonable fit clearance 5, replace the paper pad on both ends 6, carefully adjust the throttle valve at both ends of the valve