FIELD: power engineering; transformer building. SUBSTANCE: for on-line replenishment of bushings without removing them from equipment valve is opened and oil is pumped into cavity. In the process cavity reduces in volume and diaphragm compresses. Upon oil escape from nozzle the latter is closed. Pipeline is filled with oil by means of pump up to moment of its escape from valve. The latter is closed and connected to bushing. With piston moving up or down oil is supplied to bushing. During upward-downward movement of piston gage pressure is always built up in cavity above piston thereby eliminating air ingress into pump through packing as it wears down and in this way contact between air and oil is eliminated. As oil is pumped out of cavity its level reduces, and diaphragm is tightly fitted to inner surface of tank. Air penetrated into cavity through hole. Then cycle is resumed. EFFECT: simplified design, reduced metal input, enhanced quality of oil. 1 cl, 1 dwg
