Abstract: A material supply system includes a plunger pump, a pressure reducing valve, an accumulator and a dispenser. The plunger pump is connected with the pressure reducing valve by a primary supply line. The pressure reducing valve is connected with the dispenser by a secondary supply line. The accumulator is provided in the secondary supply line and has a spring. A pressure sensor senses the pressure nearly at the inlet port of the dispenser. The sensed pressure is the basis for controlling the pressure reduction ratio of the pressure reducing valve. The second chamber of the accumulator stores a sealing compound or other material. The second chamber varies in volume with the balance between the pressure in the secondary supply line and the force of the accumulator spring so as to relax the pressure fluctuation in this line.