This oil purification plant is applied to filter various of unqualified insulation oils including aging transformer oil specially for the power which is above 110KV, mutual inductor oil, switch oil and so on. Also it can inject the insulating oil into the transformers on-line. Features: 1. High vacuum: High point-Vacuum=333L/Sr. 3. Duplex 3D stereo-evaporation, eliminating the liquid water quickly 4. UK G technology by which the trace water that is show chain, such as dissolved water, can be removed effectively. 5. Distinctive removing impurities system filtering through double FH trapezoidal network and absorbing by high polymer without the mechanical power 6. Carbon fiber infrared heating system that can make the oil contains zero sum of ethyne after the treatment 7. Especially applied to vacuum oiling and drying for power transmission equipments which are over 110KV 8. The oil of any grades can be treated on line at the working site. Advantages: Comparing with the single-stage vacuum oil purifier, this machine dewater, degas and removes the impurities more quickly, more completely, and makes the oils limiting voltage-withstand value much higher. As the bridge-type vacuum linking system that can purify and also can be an independent vacuum power supply, this machine can treat the electric insulation devices.