Patent ID: 7354075

Claim:
An adapter assembly including an axially rigid intermediate ring and a screw-in part of a fluid plug-in system, the adapter assembly comprising the screw-in part having a through-opening for plugging in a plug part, an externally threaded portion having an outer thread diameter configured for screwing into a threaded bore of a base part having a surrounding surface adjacent to a mouth of the threaded bore, an actuating shoulder having an outer shoulder diameter being larger than the thread diameter, a receiving groove formed in the transition between the actuating shoulder and the externally threaded portion, and a first sealing ring being disposed in the receiving groove; the intermediate ring adapted to fit onto the externally threaded portion and having first and second axially opposite planar annular portions, the first planar annular portion configured to engage the actuating shoulder, and the intermediate ring having a first sealing ring seat on a first side facing the actuating shoulder, the first sealing ring seat and the receiving groove and the actuating shoulder forming a first sealing chamber for the first sealing ring, and the second planar annular portion being located at the terminal end of a lower ring step extending away from the actuating shoulder and having a second sealing ring seat on a side facing away from the actuating shoulder for a second sealing ring, said second sealing ring surrounding and overlapping at least one thread of the externally threaded portion of the screw-in part and said second sealing ring further having an axial length, in an optimally compressed state, substantially equal to the axial length of the lower ring step, such that, when the screw-in part is screwed into the threaded bore of the base part, the second sealing ring seat, the surrounding surface adjacent to the threaded bore, and the externally threaded portion of the screw-in part cooperate to form a second sealing chamber for the second sealing ring.