First, the import and export pressure gauge pointer swings violently, the ammeter readings dropped obviously Fault reason: Imported vaporization. Elimination methods: 1, test pump vaporization, indicating that the water recycling is too small, can increase the opening of the recirculation door or the exit door slightly open part. 2, run-time vaporization, indicating that traffic is too large, may be appropriate to close the exit door. Second, the pressure balance after the rise Failure reasons: balance damage or balance the body tube blocked. Elimination: timely stop pump maintenance, do not cause significant damage. Third, the rotor axial position change is too large cause of the malfunction: balance disc wear. Remedy: You can stop the pump check to see if the balance plate thrust is insufficient, or adjust the sleeve flow gap below. Fourth, a large number of leakage seal leakage Cause: Seal ring under the seal or seal failure. Remedy: Replace the shaft seal rubber ring, or re-adjust the shaft seal. The packing seal is replaced by packing. Fifth, the cause of water in the oil failure: Seal leak into the bearing leakage or leakage of oil cooler core. Remedy: Eliminate shaft seal leakage or oil cooler hydraulic test, the general requirements of the oil side pressure is greater than the water side pressure, but when the pump is stopped, do not turn off the cooling water gate, it is possible to make the water into the oil. Sixth, the shaft seal cooling water fault reasons: water or water pipe plug. Elimination: cleaning. Long-term non-cooling water will accelerate the packing damage. Mechanical and labyrinth seal in the case of short-term water will cause burns, such as the axis of major damage.