In order to use shape memory Ni–Ti couplings repeatedly for the joining of pipelines, one should know how the multiple mandreling (expansion) affects the temperatures of the phase transformation in titanium nickelide and the quality of the inner surface of these couplings. This problem has been studied, using three couplings of commercial Ni–45wt.%Ti (TH1) alloy, which were designed to join the pipelines with an outer diameter of 11.9 mm. During expansion by mandreling the inner diameter of the couplings increased from 11.45 to 12.00 mm. It was observed that the required mandreling force decreased by a factor of 3–4 after a 10-fold mandreling. After each mandreling the coupling was heated, and the temperature of the initial and final stages of the reversible transformation was defined by the change in the inner diameter of the coupling. A decrease of the phase transformation temperatures by 8–20°C was registered between the 2nd and 10th mandreling cycle. In every cycle the average diameter of the coupling and the deviation from the ideal circular shape were measured before mandreling as well as after mandreling and heating and cooling back to room temperature. It was found that the deviation from the ideal circular shape increased with the number of mandreling cycles. This means that the quality of the couplings deteriorates with their repeated expansion by mandreling. This should be taken into account when using the couplings again for the joining of pipelines.