A coupling element including a body for fastening to a support and a coupling member fitted with a closure valve member and mounted in the body such that the member can pivot, a sealing gasket is disposed between the body and the coupling member and the element also includes a spring which exerts a resilient force on a flange portion of the coupling member, which force is directed towards the rear of the coupling element and is suitable for pressing a first surface of the coupling element against a surface of the body, and the coupling member is provided with a second surface for bearing against an axial abutment in the event of the coupling member moves towards a front of the coupling element relative to the body.