Three-phrase sealed transformer uses the structure of no-suspend core, which make the inside and outside of fuel tank are completely separated, without oil storage tank .The change of expanding which is caused by hot during the running of transformer is compensated by expanding and shrinking of flexible corrugated piece of fuel tank ,which can saperate the transformer oil and insulator from air and water to slow down the speed of aging of transformer oil and insulator.

The seal of tank uses the oilproof rubber with high performance to ensure 20 years’ usable time under the circumstance of no-suspend core ,which can reduce the cost of maintenance and benefits to inconvenient maintenance place.