Plunger for sealing tool has a seal zone mounted on a two zones rod, the zone situated far from the seal having the better compression strength of the two

摘要

Plunger for sealing tool has a seal zone (1) engaged at one end of the rod (2). The rod itself is composed of a first zone (3) close to the seal zone and a second zone (4). Both parts of the rod have the same diameter but the first zone has a better compression strength.