For Carter 745 735C 740G transmission solenoid valve 518-5072

With the development of the hydraulic system of injection molding machine towards medium and high pressure, the pioneer relief valve is widely used in the control oil circuit of the hydraulic system of injection molding machine.

In practice, in order to maximize its effectiveness and protect the control system, accurate and timely diagnosis and elimination of the fault of the pioneer relief valve is a key link. The failure of the pilot relief valve will cause the injection molding machine to not work. According to the phenomenon, the reasons are as follows: the spool spring of pilot valve is broken; The Yin hole is blocked; Pilot valve port seal is poor; The main valve core is stuck. The corresponding exclusion measures are: replace or flatten the pad at the broken point for emergency use; Cleaning and dredging; Grind or disconnect the oil circuit for emergency use; Grinding, cleaning.

Pressure limiting instability: the pressure limiting of the leading relief valve is unstable, which is manifested as low or high pressure of the hydraulic system, weak action of the hydraulic actuator, or burst of the tubing, pump body, and valve body. The reasons for this failure are: improper pressure adjustment; The pilot valve spool spring is bent or soft; The oil is too dirty or the oil flow is not smooth. The corresponding exclusion measures are: readjustment; Correction, padding or replacement; Replace and clean. The pressure limiting instability of the pioneer relief valve is a gradual fault, and the failure of the pioneer relief valve is a sudden fault. After the fault is eliminated, the pressure controlled by the pioneer relief valve should be re-adjusted according to the pressure limited by the injection molding machine system.