A device for rapidly connecting together a tube member and a terminal pipe connector, comprising the tube member having an annular groove and a terminal end portion extending beyond the annular groove, a collar piece adapted to be introduced axially around the tube member, the collar piece having a first locking means for engaging in the annular groove of the tube member to immobilize the collar piece with respect to the tube member, and the pipe connector having a socket for receiving the end portion of the tube member together with the collar piece fitted to the latter, sealing means disposed between the connector and the tube member, and a second locking means for immobilizing the connector with respect to the collar piece, wherein said second locking means has a deformable ring at least partly surrounding the connector, said deformable ring having two opposed portions thereof, biased elastically towards each other, said connector having two opposed chordal passages, the collar piece having an annular peripheral groove, and said opposed portions of the deformable ring being arranged to pass through respective ones of said opposed chordal passages of the connector to engage in said annular groove of the collar piece.