Abstract: A process for the repair by lining of a tube (12) of a steam generator, and a lining for such repair. The lining (15) is introduced into the tube (12), is rolled in the tube (12) inside the tube plate (11) and radially expanded through rolling of its end part (18) located in the tube (12) outside the tube plate (11). Leak-proofing is ensured by brazing the end part (18) of the lining in the tube (12). In its end zone (18), the lining (15) has slots filled with brazing metal and grooves coaxial with the lining (15), which make it easier for the brazing metal to spread. The invention applies particularly to the steam generators of pressurized water nuclear reactors.

Abstract: The drive mechanism for driving the welding head (17) in rotation in the tube is arranged in a motor casing (18) inserted between first and second sections (16a, 16b) of a flexible tubing. The translational movements of the welding head (17) for positioning it in the tube (3) are provided by the sections (16a) of the flexible tubing. The transmission of rotation between the drive mechanism and the welding head (17) is provided by a flexible transmission member arranged in the second section (16b) of the flexible tubing. The device is intended in particular for welding a small repair liner at any height in a steam generator tube of a pressurized-water nuclear reactor.

Abstract: Method of repairing a steam generator tube by means of a liner, in which the mechanical deformation (19) of the liner (15), by expansion in its end part opposite the expanded end (16) inside the tube plate (11), is located at a limited height, and the parameters of the mechanical deformation (19) are calculated in accordance with the welding parameters subsequently applied. These parameters are determined in accordance with the parameters of the initial mechanical deformation (19) so as to obtain relief of the stresses more particularly in the critical zones (19a, 19b) of the mechanical deformation.