The UVD vacuum¹Vacuum is space devoid of matter. An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. filling²The term “transformer oil filling” has two meanings. The first is the process that compensates for the loss of oil in the course of transformer operation. The second is filling a transformer with oil before commissioning or after an overhaul. unit is designed for preparation (degassing³Transformer oil degassing is a complex of processes targeted at the removal of water, gasses, and mechanical impurities from the dielectric oil.), storage, transportation and adding of transformer oil into the high voltage ports of transformers⁴A transformer is a static electrical device that transfers electrical energy between two or more circuits. and switches⁵Switchgear is composed of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment.; the unit is designed for operation at power plants, substations and other energy facilities.