Tube stopper for closing a defective heat-exchanger tube, and process for removing the tube stopper

摘要

Tube stopper for closing a defective heat-exchanger tube, and process for removing the tube stopper, which comprises a hollow cylindrical part 3 which passes, without interruption of continuity, without a step, to a hollow conical part 4. The cylindrical part 3 has an external diameter which is slightly smaller than that of the heat-exchanger tube 2 to be closed. The tube stopper 1 is inserted into the heat-exchanger tube 2 and, by means of widening or, alternatively, rolling, is brought into hermetic contact with the inner surface of the heat- exchanger tube 2. In the conical part 4 are arranged means 6 for inserting a tool 15. The cylindrical part 3 has been made so as to be rough in its zone which is to be widened. In a process for releasing the tube stopper 1, its wall is melted by welding over a predetermined path 12a so that it contracts, thereby releasing the tube stopper 1. IMAGE