Created on:2021-08-27 15:30

Fault diagnosis and maintenance of marine hydraulic equipment_ Ship pressure instability or pressure regulation failure

Fault diagnosis and maintenance of marine hydraulic equipment_ Ship pressure instability or pressure regulation failure

(1) Fault phenomenon

During the opening operation of a certain ship, the pressure of the hatch cover hydraulic system gradually decreases, and it will not recover from the original 12MPa to 8Mpa, and can not be adjusted again.

(2) Cause analysis

Because the system has been used for a long time, it was initially estimated that it may be caused by severe wear and increased internal leakage after long-term use. After disassembly and inspection, it is found that the gear wear is not serious, and the axial and radial clearances are slightly increased. Readjust the clearance and conduct commissioning after reassembly, but the fault remains unresolved. However, it was found in the test run that the pressure of the system was stable at 12MPa, and now the pressure at 8Mpa is still stable. During the pressure change, no obvious damage was found in the system. According to the analysis, since the pressure is stable before and after the change, and no obvious damage is found in the system, it can be considered that the fault may occur at the overflow valve, because the working performance of the overflow valve is easily affected by other factors. Disassemble the overflow valve and check it. It is found that there is dirt and poor sealing at the valve seat. Reinstall the valve seat after cleaning, and the system pressure returns to normal.

(3) Summary

The treatment of the above problems shows that the fault is due to the accidental retention of dirt in the oil at the valve seat, which destroys the seal and drops the system pressure. After the dirt is removed, the sealing function returns to normal, so the system pressure also returns to normal. For this kind of fault, if the dirt is washed away occasionally, the system can restore the normal pressure by itself. Once the dirt stays here again, the pressure will drop again. Therefore, replace or purify the oil.

Home    Article    Fault diagnosis and maintenance of marine hydraulic equipment_ Ship pressure instability or pressure regulation failure