This product bears the outstanding features of omniseal,free-maintenance,free suspendedcore,low noise.The iron core adopts the combination of steel tape and coating epoxy resin to reduce the steel structure of leakage magnetic field and the stray loss in operation.Coil adopts the setting of separating the voltage-regulating coil and the main coil to enhance the mechanical strength,reduce coil ampere-turns imbalances and improve the anti-short-circuit capacity.The oil tank is made of steel plae into corrugated shape,reducing its overall weight and improving heat-losing ability.The upper tank and lower tank are tightly welded,enhancing the airproof.