The transformer tank is used to accumulate the windings, cores, etc. in it. The tank of small transformer is made with iron sheets having the provision of ventilation and provision for connections to the load and supply. The tank of large transformers are made with boiler plate sheet properly welded so that the oil may not come out of the tank. If the surface area of the tank is not sufficient to dissipate the heat produced, the surface area is increased by providing extra means. Elliptical tubes, round tubes are attached with the tank to increase the dissipating area. Sometimes these are also provided with the radiator facility.