Features:

The working principle of the vacuum self-compensating plunger(patent product) is that the open copper ring is always in the "open" tendency under the acting force of the built-in spring, so that the wear of the outer diameter of the copper ring is automatically compensated by the " expanding" of the ring,always allowing the outer circumference of the copper ring and the inner wall of the shot sleeve stay in a tight state, hermetically seals the inner chamber of the shot sleeve to achieve the vacuum sealing effect and increase of the service life of the plunger.

Component life: Body 30000-50000shots;

Front ring 5000-10000shots; Back ring is front ring × 2-3.