ZYD double stages vacuum transformer oil purifier is mainly used for removing trace water, gas and impurities from insulating oil, improving the insulating oil performance index. It is mainly applied to purification of 110KV, 220KV, 500KV, 750KV, 1000KV power transmission equipment insulating oil, also applied to treat low viscosity oils, like insulating oil, turbine oil, and hydraulic oil in the transmission equipment which is lower than 110KV. Meanwhile, Series ZYD oil purifier can be used as independent vacuum source with functions of vacuum drying and vacuum oiling. Insulating oil performance mainly decided by oils water content, If the water is not saturation in the oil, it appears as the molecular states; If water is saturation in the oil, it appears as the liquid states and stay at the bottom of container.