Abstract: The welding device including an adjustable connecting assembly includes a fastening mechanism (12), having a cylindrical part (12a) to be introduced into a tube (6) of a network, and a jack (12b) for actuating the cylindrical part (12a), and a welding head (11) including a centering bush (28) to be introduced into the tubular piece (8) to be welded and a welding electrode (26) mounted rotatably about the axis of the bush (28). The fastening mechanism (12) and the welding head (11) are connected by means of the adjustable connecting assembly (13) allowing relative translational movements of the welding head (11) in relation to the fastening mechanism (12) in the direction of the perpendicular common to the axis of the cylindrical part (12a) and to the axis of the bush (28) and relative rotational movements about two perpendicular axis (21, 22), one of which is parallel to the direction of translational movement (18).

Abstract: Welding is controlled from a control station (14) located at some distance from the welding zone. Before the start of a welding pass, the welding parameters are set by an operator, to whom the values to be given to the parameters as a function of the type of pass are supplied by a memory in which the information relating to the welding is stored. The welding operation is started, after the parameters have been checked as a function of the content of the memory. The welding operation is monitored continuously by the operator by means of a remote screen display of the welding zone. If appropriate, the operator changes some of the welding parameters according to the screen image of the welding zone. These changes are checked by comparison with the content of the memory.

Abstract: The televisual monitoring apparatus incorporates at least one camera (10) fastened to the support of the welding machine. The camera (10) incorporates, interposed on the path of the light rays coming from the welding zone and upstream of a device (22) for conversion of the light rays into video signals, a filter (24) composed of a plate of ceramic material having light rotatory properties and electrodes disposed in contact with each of the two faces of the plate in accordance with a determined network. The monitoring device also incorporates, associated with the camera 10, an electronic video signal analysis and electrode potential control arrangement.

Abstract: The outer shell of the linking housing (7) of the welding machine consists of a first casing (7a) and a second casing (7b), assembled together through a flat surface (44). The electrode support (10) is mounted to move in rotation in a bearing (30) fixed in the first casing (7a) about an axis of rotation (42). The shaft (40) for transmission of the rotation to the electrode support (10) is mounted to move in rotation in a bearing (28) fixed in the second casing (7b) about an axis of rotation (43). The axes (42) and (43) converge at a point 0 on the surface (44) and form an angle with the axis normal to the surface (44) at 0. The disalignment of the axes (42) and (43) can be adjusted by rotating the casings (7a, 7b) with respect to each other.

Abstract: A device (50) for treating the inner surface of a steam generator heat exchange tube (1) is introduced into the tube (1), the region to be treated is isolated from the remainder of the tube (1), an electrolyte is circulated in this region to carry out the treatment, an electrical field is created between the treatment device (50) and the tube (1) to produce a migration of ions in both directions, the electrical field created is reduced to zero, the electrolyte is removed to a treatment unit and then a compressed-air purge is carried out, the treated region is rinsed with demineralized water and the water is drained, and, lastly, an additional compressed-air purge is carried out.