As it doesn't need oil conservator, the height of transformer is reduced, and as the transformer oil doesn't contract with air, the oil ageing is retarded, thus prolonging the service life of transformer. This product is widely used in urban power grid reconstruction, residential district, factory, high-rise building, mining factory, hotel, shopping mall, airport, railway, oil field, wharf, highway and other outdoor places. 1. It’s an environment-friendly transformer with low no-load loss, no-load current and noise; 2. No oil storage box to save space; 3. Whole sealed with vacuum oil filling, high stability of insulation; 4. Adopts the corrugations on the oil tank as its heat-radiation parts, corrugations can expand or contract accord to the change of oil volume 5. Fully sealed structure, maintenance free; 6. With oil level gauge to ensure the safety running.1.High ambient temperature: +40℃ 2.Low ambient temperature: -25℃ 3.Altitude: <1000m 4.Monthly average relative humidity: 90% (20℃) 5.Installation location: Install in a place where there is no fire, explosion hazard, serious pollution, chemical corrosion and severe vibration, indoors or outdoors.