uses: mainly used for electric power, metallurgy, coal mine, etc., and electrification vacuum oil-replenishment for on-working oil-filling device, and vacuum oil-filling or replenishment for after-examination and repair oil-filling device, and especially for filling or replenishing oil for under 220kv oil-immersed transformer and metal expander, as well as providing vacuum for electric power equipment and non oil-fill device. feature djl filling machine series accumulates dehydration, removal of impurity and air-drying. delicate filtering system without oil pump attached, decreased working noisy, and enhanced the controllable function. with small size, the machine is easy to be operated, and flexible for being moved. on process of oil-filling, insulating oil keeps untouched with air. high accuracy purifying particulate substance ensures high efficient oil-filling.