Maintenance of medium and high pressure choke valve

Our factory has five injection machines, which are often stopped due to low pressure or no pressure of the hydraulic system. After inspection, the YP type medium and high pressure relief valve leaks, and the solution is as follows: 1. The cause of the failure is in the hydraulic system. Due to the frequent action of the main valve core of the YF type medium and high pressure choke valve (Fig. 1), the matching clearance at φ12mm