Reinforced tubular joint for improved sealing-tightness after plastic expansion

An expandable threaded tubular joint comprising:

• a first tubular element and a second tubular element, the first and second tubular elements having respective mating threads, the first and second tubular elements having respective first and second non-threaded lips extending between their threads and respective free ends,
• wherein each of the first and second non-threaded lips of the first and second tubular elements comprises a respective first and second sealing surface,
• the tubular joint having a first state in which the first and second tubular elements are made up together by screwing together the mating threads, and
• the tubular joint having a second state, derivable from the first state by a diametric expansion to a predetermined extent, in which second state each sealing surface comes in sealing-tight contact with an opposite surface of the other tubular element,
• wherein the tubular joint has first and second tubular sleeves having an inner diameter fitting over the second tubular element before screwing together the first and second tubular elements, the first sleeve being positioned in order to extend axially substantially opposite to the first non-threaded lip and the second sleeve to be positioned in order to extend axially opposite to the second non-threaded lip, the fitting in the first state being such that the tubular sleeves effect at least shrink-fitting directly on the second tubular element in the second state, thereby generating, in the second state, a tubular sleeve springback force which cumulates with a springback force of the second tubular element for counteracting a springback force of the first tubular element, and
• wherein the two sleeves are connected together by a brace, the sleeves and the brace being formed in one piece.