In connection with the field of corrosive fluids transport, coupling assemblies are already known for connecting a tube to a body part of another component, comprising a ring part mounted on the periphery of the tube and receiving at one end a curved end portion of the tube, and wherein the sealing is achieved by axially clamping the curved end portion of the tube against a receiving surface through said ring. A connector assembly of this type is described, for example, in patent application EP 0 584 009. However, this connector assembly has the disadvantage of not being easily adaptable to the connection of tubes of different diameters.