The flexible tube of envelope finishes with a muff, that it is applied watertight and it is slipped into the ring-like interstice of an estate muff. The estate muff is connected with an implantation ring, than through elements of implantation of position it is fixed with geometric tie on the bocchettone tubular of outflow. Ring of implantation and muff of estate possess a passing opening, that head to the magnetic valve encloses to held the making power line. The estate muff is mounted on the bocchettone tubular of outflow and through a ring of pressure mounted from the side of the cape figure is assured in position in the guard (1).