Abstract:
A joint is formed between two lengths of insulated pipes, which pipes have thermoplastic jackets. The jackets are joined together with a thermoplastic split sleeve. A welding rod arrangement is located along the edges on one side of the sleeve in a U-shaped configuration. The welding rod arrangement includes two side by side welding rods, each of which have a thermoplastic core with resistance wires embedded in the core. The split sleeve is wrapped around the joint with the sleeve overlapping the pipe jackets and also with the ends of the sleeve overlapping to form a longitudinal seam. The welding rod arrangement encircles each jacket in a partial spiral with a nonconductive core of thermoplastic located between the adjacent welding rod arrangements. In addition, the welding rod arrangement extends along the longitudinal seam. Electrical current is provided to the resistance wires, wherein the sleeve is welded to the pipe jackets and the split in the sleeve is welded closed.
Abstract:
A plasma arc pipe cutting apparatus incorporates a plasma arc torch adjustably coupled to a motor-driven ring which transports the torch in an orbit about the pipe to be cut. The apparatus includes a pipe clamping fixture allowing the pipe to be cut to be concentrically mounted within the ring so that the gap between the electrode of the plasma arc torch and the work piece remains constant through the orbital travel of the torch.
Abstract:
A drive shaft assembly includes an aluminum torque tube and aluminum yokes that are arc welded to the ends of the torque tube. The torque tube has a hollow cylindrical end portion at each end that is pressed onto an annular end portion of the respective yoke to form a narrow annular slit. The two parts are then arc welded together by forming an electric arc between the parts at the narrow annular slit and a consumable aluminum based electrode. The electric arc is sustained with a pulsed high amperage direct current to fill the narrow annular slit with aluminum based material from the consumable electrode in a single pass.
Abstract:
The girth welds joining the end plugs and the hollow tubes of nuclear fuel rods are inspected automatically using a technique that averages reflectance values, compares the reflectance values to standards defined as proportions of the average, and counts adjacent pixels outside the standards to analyze for defects exceeding a minimum defect size. The minimum defect size is checked by counting the adjacent pixels in mutually perpendicular directions, such as rows and columns in the collected matrix of pixel data. The maximum count in the two directions can be different, for profiling the maximum acceptable defect as to the direction of its extension relative to the tube and/or weld. Tubes are inspected prior to surface treatments that may conceal defects. The tube is fed, illuminated and rotated for at least one revolution at an inspection station, collecting line scans at regular angles synchronously with rotation using a line scan camera coupled to a digitizer to obtain the matrix of data encompassing the girth weld. A numerical processor averages, compares and counts the number of adjacent pixels for assessing weld quality.
Abstract:
Process, apparatus and nozzle device for controlling the soldering and/or desoldering of a land grid array (LGA) component and corresponding circuit grid present on the surface of a printed circuit board (PCB). The nozzle device comprises a vacuum cup for supporting the LGA parallel to the PCB, with the LGA and the circuit grid in contact or slightly spaced, a fixed orifice gap for directing hot inlet gas from a gas source horizontally through the array, a gas outlet, and a thermocouple for sensing the temperature of the hot outlet gas and for signaling a computer to actuate a heater and a flow rate regulator. According to a preferred embodiment, this increases the temperature and decreases the flow rate of the hot gas through the array when a predetermined gas outlet temperature is sensed at the thermocouple. Uniform slower circulation of the hotter gas is continued for the desired dwell time to produce uniform, simultaneous melting of the solder array to permit bonding to or desoldering from the circuit array of the PCB while supporting the component parallel to the PCB.
Abstract:
A welding system for superhigh purity gas supply system, capable of removing easily and completely the metals deposited, during the installation of the superhigh purity gas pipe system, on the outer surfaces of the portions of the pipes which are closed to the portions to be welded thereof and on the inner portions of these pipes, and capable of setting up a superhigh purity gas supply system in a short period of time. A welding system for the gas supply pipe system in which a plurality of members are connected together by welding, characterized in that a first member to be welded(113) is provided with a means for supplying an inert gas or a welding back seal gas and a means for supplying superpure water, a second member to be welded(114) being provided with a means for discharging the inert gas or back seal gas and a means for discharging the superpure water, the first and second members being welded as the inert gas or back seal gas is being supplied, the superpure water being supplied after the welding of these members has been completed, whereby the metal fume deposited on the surfaces of the welded members during the welding thereof can be washed out.
Abstract:
A method and apparatus for preventing catastrophic melting of the contact be in continuously-fed consumable electrode arc welding due to wire feed interruptions by monitoring the movement of the wire electrode with a high frequency sensor such as all optical encoder having a resolution on the order of
Abstract:
A joint for brazing includes a male member having an external surface and a female receptacle having an internal surface. The external surface is positionable in face-to-face relationship with the internal surface when the male member is inserted within the female receptacle. A self-fixturing surface is provided on at least one of the male member and the female receptacle for centering the male member with respect to the female receptacle when the male member is inserted within the female receptacle and to provide substantially equal clearance between and around the male member and the female receptacle for proper capillary attraction of the metallic intermediate bonding material or filler alloy during brazing. The filler alloy is drawn by capillary attraction into the space between the meeting faces defined by the external surface of the male element and the internal surface of the female receptacle. The self-fixturing surface preferably is formed as a knurled surface on the external surface of the male element.
Abstract:
The metal of the wall of the part (13a) in a zone which includes defects such as cracks is melted, over a defined depth, by moving over the surface of the part with the aid of a melting device (21), and then solidified. Next, a surface layer of the metal of the wall of the part (13a) which has been melted and then solidified is subjected to compression by repeated impacts of solid particles. The melting is preferably performed by a transferred-arc plasma (22) and the compression by balls set into motion by a vibrating part. The invention applies in particular to the repair of a tubular adaptor (13a) penetrating the head (1) of a nuclear-reactor vessel.
Abstract:
The component comprises a body (5) composed of an alloy based on a .gamma.-titanium aluminide, a steel body (2) and a connecting piece (4) composed of a nickel-base alloy. The .gamma.-titanium aluminide body (5) and the steel body (2) are rigidly joined together by means of the connecting piece (4). The joint between the .gamma.-titanium aluminide body (5) and the connecting piece (4) is produced by friction welding. The nickel-base alloy has a nickel content of less than 65 percent by weight. This achieves the result that the friction-welding joint of the .gamma.-titanium aluminide body (5) to the connecting piece (4) can be produced at comparatively low temperatures. During the friction welding, the risk of crack formations in the embrittlement-prone .gamma.-titanium aluminide body (5) is therefore appreciably reduced.