This coupling element has a body and a nozzle. The body delimits a housing for partially receiving the nozzle. The nozzle has a tubular part and a flange received in the housing. Two sealing barriers formed by at least one sealing joint are interposed between a rear surface of the flange and a front face of the body, between a front surface of the flange and a rear face of the body, respectively. A plug caps an inner conduit. Portions of the inner conduit communicate through at least one passage opening into an inner volume of the nozzle, forward of the plug, and on an outer peripheral surface of the flange. An inner chamber is separated from the inner conduit by the body, the flange, the plug and the first sealing barrier.