Abstract: The simultaneous straightening and insertion of tubular sleeves into damaged heat exchanger tubes is accomplished by passing a pre-bent tubular sleeve through a bending apparatus utilizing three forming rolls. One of the forming rolls can selectively be moved toward the other two to compensate for varying radii of curvature. The apparatus is equipped with a pneumatic or hydraulic cylinder capable of pulling the tubular sleeve through the bending apparatus in incremental steps. By simultaneously straightening and inserting pre-bent tubular sleeves into damaged heat exchanger tubes, the tubular sleeves can be inserted into damaged tubes which are in positions which would otherwise be impossible to be repaired by this method. This method effectively circumvents the proscription of straight tube insertions into damaged heat exchanger tubes from the quarter spherical chamber of the heat exchanger.

Abstract: A cam-controlled boring bar system (100) includes a first housing (152) which is rotatable about its longitudinal axis (154), and a second housing in the form of a cam-controlled slide (158) which is also rotatable about the axis (154) as well as being translatable therealong. A tool-holder (180) is mounted within the slide (158) for holding a single point cutting tool. Slide (158) has a rectangular configuration and is disposed within a rectangularly configured portion of the first housing (152). Arcuate cam slots (192) are defined within a side plate (172) of the housing (152), while cam followers (194) are mounted upon the cam slide (158) for cooperative engagement with the cam slots (192). In this manner, as the housing (152) and slide (158) rotate, and as the slide (158) also translates, a through-bore (14) having an hourglass configuration will be formed within a workpiece (16) which may be, for example, a nuclear reactor steam generator tube support plate.

Abstract: A minimum-wear through-bore (16) is defined within a heat exchanger tube support plate (14) so as to have an hourglass configuration as determined by means of a constant radiused surface curvature (18) as defined by means of an external radius (R3), wherein the surface (18) extends between the upper surface (20) and lower surface (22) of the tube support plate (14). When a heat exchange tube (12) is disposed within the tube support plate (14) so as to pass through the through-bore (16), the heat exchange tube (12) is always in contact with a smoothly curved or radiused portion of the through-bore surface (16) whereby unacceptably excessive wear upon the heat exchange tube (12), as normally developed by means of sharp edges, lands, ridges, or the like conventionally part of the tube support plates, is eliminated or substantially reduced.

Abstract: A remotely controlled tool for working inside a steam generator hemispherical head on tubes and tube holes and moving along orthogonal x and y axes to conform to the tube layout pattern in the tubesheet.

Abstract: A welding torch is rotatably mounted in a carriage. The carriage and welding torch are driven by motors and driveshafts mounted on a base to provide a light carriage which can be rapidly accelerated as the torch moves from tube to tube when forming a continuous weld encompassing the juncture of a plurality of tubes.

Abstract: A gas tungsten arc welding torch having an elongated gas nozzle (18) with an oblong cross section designed for deep groove, narrow gap welding. The nozzle is rotatably coupled to and communicates with a gas port within the main torch body (16) and defines a gas passage along the length of the welding electrode (10), which extends through the longitudinal axis of the nozzle. The nozzle (18) includes a detachable end section (42) which captures and supports a replaceable gas lens (30) disposed within the gas passage of the nozzle within 7/8 to 1 inch from the nozzle orifice (40), and traverse to the direction of gas flow. The electrode (10) is formed from a solid tungsten rod center (12) and a concentric outer sleeve (14) substantially lower in electrical resistivity than the tungsten rod, which is adhesively and cohesively bonded to the tungsten. The outer sleeve extends from the point of electrical connection (32) within the main torch body (16) to a point on the tungsten electrode downstream of the gas lens.

Abstract: A method of applying a gas shielded tungsten arc welding process in a deep, narrow groove joint wherein the shield gas is directed to the weld puddle through an elongated gas nozzle 14 which surrounds a substantial length of the welding electrode and is sized to extend into the groove. The improvement including incrementally increasing the width (20) of the nozzle to correspond to increases in the width of the groove at preselected increases in the width of the groove as the nozzle is withdrawn from the groove during successive weld passes. The preselected elevations and nozzle widths are chosen so that the desired gas shield area does not substantially exceed 1.25 times the nozzle width.

Abstract: Apparatus for automatically welding a plug which is previously driven into holding engagement with the tube sheet to plug a leaky tube which has been reamed out to produce a pressed fit with the plug.

Abstract: Apparatus that is assembled quickly inside a channel head of a steam generator and is capable of performing various repair and inspection techniques remotely in order to reduce radiation exposure and facilitate rapid repair of the tubes.

Abstract: An apparatus for serially driving a tapered plug in a tube and forming a peripheral seal weld at the juncture between the plug and the tube.

Abstract: A multihead welding gun which has one or more self-aligning heads for simultaneously forming 360.degree. welds between the juncture of recessed tubes and a tube sheet.

Abstract: A method of repairing a tube in a heat exchanger by severing the tube and welding a sleeve inside the tube.