The method of the residual oil pump to prevent leakage in the oil, the pump repeatedly exceeds the phenomenon of excessive moisture of the lubricating oil, and even the lubricating oil is emulsified. After inspection and analysis, it was found that the feed water to the pump oil was mainly from the sealed water. To prevent water in the lubricant, the following precautions are taken: 1. Strictly control the sealing water differential pressure of about 150kpa, not more than 180kpa, to avoid the high sealing water pressure into the bearing bush. 2. Carefully check the sealed water back to the water window during inspection. It should not be filled with water and water, and there should be no water in the bearing shell. 3. When the residual oil pump starts and stops, when the vacuum is lower than 85kpa, the sealed water returns to the atmosphere in time to prevent the return water from entering the bearing. 4. When the sealing water adjustment performance is not good, contact and repair in time.