... applied to purification of 110KV, 220KV, 500KV, 750KV, 1000KV power transmission equipment insulating oil, also applied to treat low viscosity oils ... insulating oil, turbine oil, and hydraulic oil in the transmission equipment which is lower than 110KV. Meanwhile, Series ZYD oil ... oil flow backwards. 2. Double-stage vacuum system, strong power of vacuum evacuating, ultimate vacuum value ≤ 5Pa 3. Two ...