Abstract: The invention relates to a ringed tubular sheath including at least one internal means (5) for clamping a tube (11) in particular, and more specifically a smooth tube, located inside said sheath, said sheath being unique in that at least one flexible area (8) is associated with the internal clamping means (5). The invention also relates to a method for manufacturing such a sheath, and to a method for maintaining a ringed tubular sheath on a tube (11), in which: a ringed tubular sheath is used according to the invention; the flexible area(s) (8) are controlled such as to the deform the sheath; the tube (11) is inserted in the ringed tubular sheath, and the flexible area(s) (8) are then released.