10kV distribution and transmission line is the most common urban power lines. 10kV oil-immersed type distribution transformers are important equipment in the distribution lines and power supply and distibution systems of industrial & mining enterprises. It has the advantages of compact structure. There are such characterics as beautiful appearance, smallsize, low noise, and strong overload capacity. 10kv class three phase oil-immersed distribution transformer has hermetically sealed type and conservator type, The transformer is applicable to plant, mine, petrol chemical and other power distribution system of 10kV class for industry and agriculture. They are also popular in sites with oil contamination and chemical substances.