Methods Patents (Class 219/61)
  • Patent number: 5192016
    Abstract: A method of manufacturing tubes filled with powdery and/or granular substances, such as flux-cored welding wires. A tube filled with a powdery and/or granular substance is continuously manufactured by forming a metal strip being fed in its longitudinal direction into an unwelded tube (1a) using forming rolls (2), feeding a powdery and/or granular substance (F) into the unwelded tube (1a) being formed through its opening, butt-welding together fringing edges of the opening, and reducing the diameter of the welded tube (1b). An allowable minimum heat input below which cold cracking occurs and a maximum allowable heat input above which spatters whose diameter is not smaller than 0.83 times the inside diameter of the finished tube are generated are determined in advance, and the butt welding is performed with a heat input larger than the allowable minimum heat input and smaller than the allowable maximum heat input.
    Type: Grant
    Filed: February 21, 1992
    Date of Patent: March 9, 1993
    Assignees: Nippon Steel Corporation, Nippon Steel Welding Products & Engineering Co., Ltd.
    Inventors: Nobuo Araki, Takeji Kagami, Yoji Chatani, Shunichi Kikuta, Iwao Yamada, Masao Kamada, Seiji Hashimoto, Shuichi Ueno, Takeshi Fukui, Takumi Nakamura, Nobuo Mizuhashi, Yasushi Ishikawa
  • Patent number: 5171954
    Abstract: In a method for welding together pipe ends of pipes held mutually in line the welding process is automatically controlled subject to the angular distance traversed by the welding lance.
    Type: Grant
    Filed: January 10, 1991
    Date of Patent: December 15, 1992
    Assignee: Atlantic Point Incorporated
    Inventor: Fernando Rinaldi
  • Patent number: 5140140
    Abstract: A method and apparatus for submerged arc welding using five-electrodes having direct current (DC) connected to one electrode and alternating current (AC) connected to the other four electrodes. The electrodes are aligned in a row with predetermined angles to the direction of the weld. Alternating current is supplied to the electrodes so that a phase difference is applied to adjacent electrodes and a phase difference is applied between alternating electrodes. With such power application and the electrical connections of the electrodes, the welding process has a more stable weld puddle that suppresses welding defects at higher speeds than previously achievable.
    Type: Grant
    Filed: November 15, 1990
    Date of Patent: August 18, 1992
    Inventor: Alex J. Pollack
  • Patent number: 5140123
    Abstract: A continuous manufacturing method for a metal welded tube and a manufacturing apparatus therefor, which obtains a tubular member by continuously passing a metal band coil through molding rollers, guides the tubular member to abutting rollers to bring the edges thereof in slight contact with each other so as to form a V-throat having the vertex of an edge contact portion at the upstream side of the abutting rollers, disposes an inductor of a high frequency preheating unit aiming at edge preheating at the outer periphery in front of the abutting point of the V-throat and at need disposes an impeder also at the inner surface of the V-throat, and further disposes welding torches in a single or double rows of a welding unit for melting and welding the tubular member by welding high density energy at the upstream side of the abutting rollers including the line connecting the centers thereof.
    Type: Grant
    Filed: May 25, 1990
    Date of Patent: August 18, 1992
    Assignee: Kusakabe Electric & Machinery Co., Ltd.
    Inventor: Kazuo Mitani
  • Patent number: 5134267
    Abstract: A method of conducting circumferential welding on electric welded steel pipes to form a continuous line pipe to be laid on the sea bottom by a reel barge method. The formation of the final welding layer is executed with a welding material having a strength which is 5 kg/mm.sup.2 or more lower than that of the welding material used for forming the welding layers underlying the final layer. Preferably, the reinforcement of weld is formed to meet the conditions of:2 mm.ltoreq.radius of curvature at the toe of of toe of weld0.8 mm.ltoreq.height of reinforcement of weld.ltoreq.1.8 mmPreferably, the electric welded pipes as the base metal has the composition: containing C: 0.03 to 0.20 wt %; Mn: 0.50 to 1.5 wt %; Si: 0.05 to 0.50 wt %; Al: 0.005 to 0.060 wt %; Nb, V and Ti in total: not greater than 0.040 wt %; and the balance substantially Fe and incidental impurities, Preferably, the carbon equivalent Ceq and the weld cracking sensitivity Pcm, satisfy the following conditions of:0.20.
    Type: Grant
    Filed: June 29, 1990
    Date of Patent: July 28, 1992
    Assignee: Kawasaki Steel Corporation
    Inventors: Takuya Atsumi, Katsuomi Tamaki
  • Patent number: 5134268
    Abstract: On conventional method of surfacing the interior of a pipe employing arc welding techniques is to apply a series of annular weld strips to the pipe. A simpler, more efficient method is to apply longitudinally extending strips to the interior of the pipe, while rotating the pipe between each welding metal application.
    Type: Grant
    Filed: September 20, 1990
    Date of Patent: July 28, 1992
    Inventor: Teodor D. Capitanescu
  • Patent number: 5030812
    Abstract: A method for one-side root path welding of a pipe joint comprises the steps of forming a ring groove having a V-shaped bottom portion thereof at end faces of both pipes whose joint is circumferentially welded, attaching a backing material to a butt portion of the pipes from an internal side of the pipes, running an automatic welding machine along a guide rail mounted on an outer surface of the pipes in the circumferential direction thereof, controlling a position of a welding torch along a seam by means of an arc sensor, and welding root pass from the outer side of the pipes with a predetermined welding current and at a welding speed in a high-speed rotating arc welding of the pipes at a predetermined rotational speed and with a predetermined diameter of rotation. The rotational speed of arc is from 10 to 150 Hz. The rotation diameter of the arc is from 1 to 4 mm. The welding current is from 200 to 500 A. The welding speed is from 75 to 300 cm/min.
    Type: Grant
    Filed: April 23, 1990
    Date of Patent: July 9, 1991
    Assignee: NKK Corporation
    Inventors: Yuji Sugitani, Masatomo Murayama
  • Patent number: 5013880
    Abstract: In a process for welding a pipe string driven horizontally into the ground to a follower pipe, the pipe string buried in the ground and the follower pipe are rotated. A welder then does not need to make vertical welds but can form the weld seams in a position that is most comfortable for him.
    Type: Grant
    Filed: November 16, 1989
    Date of Patent: May 7, 1991
    Assignee: Dipl.-Ing. Paul Schmidt
    Inventor: Franz-Josef Puttmann
  • Patent number: 5001320
    Abstract: A pipe welding connector for joining pipe sections that have been internally coated with a heat sensitive coating material. The connector is arranged so that during the welding process, the coating remains below its degradation temperature. The connector has a first fixture at the end of one pipe section and a second fixture at the end of another pipe section. The first and second fixtures, when brought into abutting relationship, can be butt welded together to form the pipe welding connector. The second fixture is a cylinder that outwardly diverges into a bell and the opposed marginal end is of constant inside diameter and is attached about the exterior of a pipe section. Part of the pipe section extends from the belled marginal end and forms a stinger. The first fixture has an enlarged interior that telescopingly receives the stinger therein and further includes a belled marginal terminal end of a diameter equal to the diameter of the belled marginal end of the second fixture.
    Type: Grant
    Filed: November 14, 1988
    Date of Patent: March 19, 1991
    Inventors: Ralph N. Conley, Michael N. Pierce
  • Patent number: 4937427
    Abstract: An apparatus and a method for automatically welding a T-junction connector to a main pipe are disclosed. The apparatus includes a rotatable frame which is provided with a movable bracket for supporting a welding gun. The frame is preferably attached by a vertical shaft to a portable framework having a wheeled leg and a pair of spaced apart horizontal handles. The portable framework may be moved from one location to another on its wheeled leg. The frame is rotated about the shaft by a computer controlled motor. Two other motors mounted to the frame are interconnected with the bracket for supporting a welding gun or torch, and adapted to move the welding gun along axes parallel with and normal to a T-junction connector supported in a preformed hole in a main pipe.
    Type: Grant
    Filed: March 23, 1989
    Date of Patent: June 26, 1990
    Inventor: Noel McVicker
  • Patent number: 4916281
    Abstract: Disclosed is an improvement in the process of gas back-purging the root section of the weld during open-butt welding of pipe. The rates of gas flow in back-purging and in torch shielding are controlled and a ratio between the flow rates is established. The invention teaches a gas back-purging flow rate of about 40 CFH and a torch shielding flow rate of about 10 CFH under typical conditions to maintain a required 4 to 1 ratio of the flow rates.
    Type: Grant
    Filed: February 23, 1989
    Date of Patent: April 10, 1990
    Assignee: Haynes International, Inc.
    Inventors: Lee M. Flasche, Gregory L. Hoback, James L. Meyers
  • Patent number: 4908491
    Abstract: An apparatus method for pipe end preparation and end to end welding of pipes comprises a stationary annular clamp (4) for both clamping and round up of pipes (2). It also has one or two rotating tool carrier rings (5) mounted at one or both sides of the clamp (4) on a track (6). The rotating ring may have thereon devices for cutting, machining of grooves, welding and non-destructive testing (NDT). The round up of the pipe is performed via 6 or more clamping shoes independently operated by screw jacks (18), a wedge mechanism (15) or directly acting hydraulic cylinders.
    Type: Grant
    Filed: July 19, 1988
    Date of Patent: March 13, 1990
    Assignee: Norsk Hydro A.S.
    Inventor: Hans O. Knagenhjelm
  • Patent number: 4857691
    Abstract: A welding apparatus includes a housing defining a welding chamber and an access opening at one end thereof. The access opening allows an end of a tube fitted with an end plug to pass into and from a welding position within the chamber. An end stop for supporting the end plug at the welding position is rotatably mounted to the housing and disposed in the chamber opposite from and axially aligned with the chamber access opening. The end stop has an annular collar-like portion adapted to fit over and engage the exterior of the end plug. The end stop also has an inner hollow tube-like portion adapted to fit into a central passage of the end plug and engage the interior of the end plug. The end stop has an orifice adapted to supply flow of inert cover gas into the end plug central passage and therefrom into the tube interior to purge air therefrom.
    Type: Grant
    Filed: June 2, 1988
    Date of Patent: August 15, 1989
    Assignee: Westinghouse Electric Corp.
    Inventor: David A. Boatwright
  • Patent number: 4837419
    Abstract: A welding apparatus has a welding chamber with an access opening allowing passage of a cladding tube end fitted with an end plug to a welding position therein. A rotatable end plug stop assembly disposed in the chamber and axially aligned with the access opening is adapted to engage the end plug when inserted in the welding chamber. An end of a electrode of a girth welding assembly disposed in the welding chamber adjacent to the rotatable end plug and tube end and in generally orthogonal relation thereto is operable to form a girth weld circumferentially joining the end plug and cladding tube end. An end seal welding assembly mounted to the end plug stop assembly and having an electrode with an end disposed adjacent to and in axial alignment with an axial bore of the end plug is operable to form an end seal weld therein.
    Type: Grant
    Filed: June 2, 1988
    Date of Patent: June 6, 1989
    Assignee: Westinghouse Electric Corp.
    Inventors: David A. Boatwright, Robert Duncan, Kenneth K. Klapper
  • Patent number: 4760232
    Abstract: A method of cladding a steel roll, such as a felt roll with a non-corrosive shell, ensures that the shell is tightly fitted to the core and is free to expand and contract on the core to avoid distortion problems. The method comprises the steps of preparing two stainless steel shells each having a length equivalent to the circumference of the core plus a predetermined extra, wrapping the shells about the core, side by side, leaving a predetermined circumferential gap between the shells, heating and clamping the shells tightly around the core until the longitudinal joints each attain a predetermined longitudinal gap, welding the longitudinal gaps, and circumferential gap between the shells while the shells are hot, ensuring the sheets are welded together and not welded to the core.
    Type: Grant
    Filed: September 14, 1987
    Date of Patent: July 26, 1988
    Assignee: Mec-Fab Inc.
    Inventor: Ken M. Smith
  • Patent number: 4666775
    Abstract: An improved process for sintering extruded powder shapes comprising drying or calcining an extruded shape in a microwave furnace and rapid sintering the shape in a plasma fired furnace. Alternatively, calcining or drying may take place within a furnace heated by the plasma furnace's exhaust. The process of the invention is especially useful for silicon carbide extruded materials and for tubular shapes. This process significantly reduces sintering times and costs. Use of the process yields a high strength sintered product.
    Type: Grant
    Filed: January 3, 1986
    Date of Patent: May 19, 1987
    Assignee: Kennecott Corporation
    Inventors: Jonathan J. Kim, Viswanathan Venkateswaran
  • Patent number: 4659903
    Abstract: The invention relates to a machine for automatically welding and/or cutting the junction point between a main pipe and a secondary branch pipe placed thereon. This machine comprises a positioning support on which the main pipe is placed. The positioning support comprises two servomotors which drive the main pipe in rotation about the longitudinal axis of the pipe and about a second horizontal axis perpendicular to said longitudinal axis. The machine comprises a travelling gantry crane which bears three carriages movable by three servomotors along three axes rectangular with each other, one of which is vertical. One of the carriages bears a welding or cutting head.
    Type: Grant
    Filed: June 28, 1984
    Date of Patent: April 21, 1987
    Assignee: Societe Nouvelle des Ateliers et Chantiers du Havre
    Inventors: Jean Berne, Georges Livet
  • Patent number: 4633554
    Abstract: This is a method for repairing low alloy steel steam turbine (both high pressure and low pressure sections) or generator rotors. The defective section of the original rotor is removed and a replacement end is used, with mating attachments machined on the replacement end and the original rotor. The inner portion of the weld joining the replacement end to the original rotor is provided by a narrow gap weld, either by gas metal or by submerged arc welding. The outer 1/2-2 inches of the weld is provided by gas tungsten arc welding. The mating attachment and at least the inside 1/4 inch of the weld is bored out to remove possible crack initiation sites and to provide a smooth inspectable bore. In this manner, a fast and reliable technique is provided which provides accurate alignment, fast, essentially distortion free welding, and the superior mechanical properties of gas tungsten arc welding in the outer, more highly stressed zones.
    Type: Grant
    Filed: August 8, 1985
    Date of Patent: January 6, 1987
    Assignee: Westinghouse Electric Corp.
    Inventors: Robert E. Clark, Dennis R. Amos
  • Patent number: 4626644
    Abstract: A method for restarting the longitudinal welding seam when producing thin-walled tubes from a metal tape comprises the steps of starting welding with the tape in motion and the welding current amperage being gradually raised from zero to the steady state values, a steady state step in which the longitudinal welding seam is continuously produced and the welding current amperage is at its steady state value, a third step in which the welding is stopped and the welding current amperage is gradually decreased from its steady state value to nearly zero, and a restarting stage in which the welding seam is overcast partially behind the point at which it had been stopped and the welding current amperage is gradually raised from nearly zero to the steady state value once again. An apparatus for performing the method is also disclosed.
    Type: Grant
    Filed: May 11, 1984
    Date of Patent: December 2, 1986
    Assignee: CISE-Centro Informazioni Studi Esperienze S.p.A.
    Inventor: Aldo Parmeggiani
  • Patent number: 4593445
    Abstract: An apparatus and a method for remotely refurbishing valve seats are disclosed herein. The apparatus generally comprises a welding assembly having a welding head for depositing a bead of metal around the valve seat, and a positioning assembly detachably mountable onto the valve body for angularly and radially moving the welding head around the valve seat at a selected point along the axis of rotation of the seat. Additionally, the apparatus includes a control means operatively connected to the positioning assembly for controlling the movement of the welding head around the valve seat. In operation, the control means, which may include a microprocessor, first angularly moves the welding head around the circumference of the valve seat, then moves the welding head to a different point along the axis of rotation of the valve seat, and then rotates the welding head around the valve seat again for as many cycles as is necessary to rebuild the valve seat.
    Type: Grant
    Filed: November 13, 1984
    Date of Patent: June 10, 1986
    Assignee: Westinghouse Electric Corp.
    Inventors: David A. Snyder, David M. Glosecki
  • Patent number: 4575611
    Abstract: A method of replacing a defective circumferential butt joint in a metal pipe is disclosed. An annular metal bridge ring, having a smaller wall thickness than the pipe but the same inside diameter, is positioned coaxial with the pipe in the relatively wide gap created by the removal of the defective joint. The ring becomes an integral part of the weld by being welded in place, thereby partially filling the gap between the edge surfaces of the pipe exposed by the removal of the defective joint. Subsequent layers of fusible material are weld deposited in place on top of the ring until the gap is filled to the exterior pipe surface. Use of the ring in the gap enables replacement of the defective joint with a single weld.
    Type: Grant
    Filed: December 26, 1984
    Date of Patent: March 11, 1986
    Assignee: General Electric Company
    Inventor: Donald C. Bertossa
  • Patent number: 4570051
    Abstract: A method and system for enclosing a gas at a preselected pressure in a nuclear reactor fuel rod having two ends open to its interior. Hermetically enclose each end in a separate airtight chamber. Introduce the gas into the first chamber and open the second chamber to purge the fuel rod interior and both chambers of residual atmosphere. After purging close the open second chamber and determine the gas pressure in the fuel rod interior. When the pressure reaches the preselected value, hermetically seal each fuel rod end while in its respective chamber. After sealing, remove the fuel rod from the chambers.
    Type: Grant
    Filed: December 13, 1982
    Date of Patent: February 11, 1986
    Assignee: Mitsubishi Nuclear Fuel Co. Ltd.
    Inventor: Nobuo Miwa
  • Patent number: 4559430
    Abstract: A method for performing automatic circumferential welding around the circumference of a butt joint of a fixed pipe or the like. First, an initial set-up operation is performed wherein a welding head is moved around the welding circumference while producing pulses indicative of the amount of movement of the welding head. The number of pulses required to move the welding head one complete revolution is counted. Next, angles at which the welding conditions are to be changed are specified. These angles are converted to the form of pulses from a start point using the number of pulses previously counted. For the actual welding operation, pulses are again counted while moving the welding head. Each time the pulse count reaches one of the specified angles, a controller instructs a new set of welding conditions to the welding head.
    Type: Grant
    Filed: October 5, 1984
    Date of Patent: December 17, 1985
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Yoshitaka Hayakawa
  • Patent number: 4535214
    Abstract: In order to join a tube to a tubesheet of a heat exchanger, the end of the tube is inserted into a socket at the end of a hole that passes through the tubesheet. The socket is large enough to receive the tube, but the hole is not, so the tube bottoms out in the socket and is thus located both radially and axially by the socket. A ring mold is fitted around the tube and moved against the tubesheet, so that its end fits into an annular groove that surrounds the socket in the back face of the tubesheet. The ring mold has a chamfered confining surface that surrounds the tube where the tube emerges from the socket. Once the ring mold is in place the portion of tube that is within the socket is welded autogenously to the tubesheet by rotating an electrode within the hole. The molten weld metal flows outwardly to the confining surface, but is prevented by that surface from flowing circumfentially, even when the welding is performed with the tube in a horizontal position.
    Type: Grant
    Filed: August 26, 1983
    Date of Patent: August 13, 1985
    Assignee: Nooter Corporation
    Inventors: John J. Meyer, Stanley D. Barth
  • Patent number: 4528436
    Abstract: An improved system (50) for shielding a circumferential region about elongate workpieces from air contamination during welding or heat treatment includes a pair of generally cylindrical shields (52, 54) which define central openings for receiving the workpieces, and which are positioned in longitudinally spaced apart relationship about the joint or region to be welded or heat treated. The shields (52, 54) are of symmetrical but otherwise identical construction. For example, the shield (52) includes a first annular chamber (70) and associated annular diffuser positioned adjacent the process zone, and a second annular chamber (86) and associated cylindrical diffuser (90) extending away from the zone. The chambers (70, 86) are connected to independent sources of inert gas, which flows both into and out away from the process zone to eliminate air contamination from aspiration and the like.
    Type: Grant
    Filed: March 20, 1984
    Date of Patent: July 9, 1985
    Assignee: Westinghouse Electric Corp.
    Inventor: Israel Stol
  • Patent number: 4527033
    Abstract: An improved welding method for welding an inner seam of a longitudinally welded steel pipe along an inner groove by welding electrodes held by a boom which is supported by a tracing roller moving along the inner groove of the steel pipe. According to the invention, at least one metal plate is urged against at least one end of the steel pipe after tack welding the seam on an opposite side of the inner groove of the steel pipe to be welded. Lateral angular deformations of the end of the steel pipe are prevented on both sides of the seam. Such deformations are due to the load of the boom when the tracing roller leaves the end of the steel pipe for the metal plate. Thus, the invention provides for prevention of hot cracking at the end of the pipe.
    Type: Grant
    Filed: May 23, 1983
    Date of Patent: July 2, 1985
    Assignee: Kawasaki Steel Corporation
    Inventors: Junya Matsuyama, Akio Kamada, Fumimaru Kawabata, Tatsufumi Uegaki, Shigeru Miyake
  • Patent number: 4514443
    Abstract: Apparatus for coating an internal wall of a curved conduit (50) with a layer of protective material, characterized in that it comprises a guide means (46, 46a), a longitudinally flexible member (44) which is transversely substantially rigid associated with the guide means, means for mounting a coating means (62) adjacent a first end of the flexible member for incremental rotation with the flexible member, a drive means (28) for driving the flexible member relative to a curved conduit (50) to be coated, so that the coating means can enter the curved conduit in use and so that the coating means can deposit a strip of protective material longitudinally of the conduit, and means (32, 34, 36) acting on the flexible member for automatically stepping the flexible member and consequently the coating means by a rotational increment after the coating means has completed a traverse of the conduit and for automatically reversing the drive means so that the apparatus deposits a strip of protective material adjacent the fi
    Type: Grant
    Filed: September 8, 1983
    Date of Patent: April 30, 1985
    Inventor: Gene Kostecki
  • Patent number: 4506135
    Abstract: For the manufacture of heat exchanger tubes having a metal strip (tangential surface) welded to the surface of the tube, the metal strip is fastened to the surface of the tube by through-welding with welding current of alternating value.
    Type: Grant
    Filed: January 21, 1983
    Date of Patent: March 19, 1985
    Assignee: kabelmetal electro Gesellschaft mit beschrankter Haftung
    Inventors: Gerhard Ziemek, Friedrich Schatz, Dieter Muller, Douglas W. Rowell
  • Patent number: 4493963
    Abstract: A method and machine for weld cladding, particularly for welding material to a cylindrical plate, such as hardfacing or corrosion resistant alloys normally applied as claddings. The machine has a mandrel extending from it for supporting and rotating the plate. The mandrel is supported by beams and driven either by hand or by a motor. Rotating the mandrel rotates the plate supported on the mandrel through the path of a welding apparatus. Flanges can be provided to hold the plate on the mandrel. Bearings can be provided in the beams to facilitate the rotation of the mandrel.
    Type: Grant
    Filed: September 9, 1982
    Date of Patent: January 15, 1985
    Inventor: Roman Arnoldy
  • Patent number: 4481399
    Abstract: Welding of tubes to tube plates using a non-consumable electrode to locally melt the wall of a tube and an adjacent area of the tube plate where the tube has been entered into a hole in the tube plate and including an initial weld preparation comprising the machining of one face of the tube plate to produce respective annular grooves concentrically around the holes into which the tubes are subsequently to be entered for welding.
    Type: Grant
    Filed: August 9, 1982
    Date of Patent: November 6, 1984
    Assignee: Robert Jenkins & Co.
    Inventor: Alan Greenfield
  • Patent number: 4479043
    Abstract: The h.f.-heated edges of a split tube are prepared prior to heating by means of contour-rolling the edges in order to obtain a convex contour in which the temperature is isothermically distributed, parallel to the convex edges.
    Type: Grant
    Filed: April 19, 1982
    Date of Patent: October 23, 1984
    Assignee: Mannesmann Aktiengesellschaft
    Inventors: Walter Hess, Franz Nicolai, Erich Treiss, Otto Gotting
  • Patent number: 4454405
    Abstract: In a welding procedure for joining of adjacent, possibly partially enclosed metal components, such as pipe sections, wherein the welding procedure can be of a gas tungsten arc type such as a heli-arc type, or similar process, and wherein oxidation of metal frequently occurs within the components at the joinder point due to presence of oxygen in the region of weld during the welding procedure; introducing under pressure and at least initially pressure blowing, at a relatively high pressure, an inert gas into the interior of the components in a substantial swirling and interior surface wiping motion. The inert gas is blown through the components, from the entry end, beyond the weld region to rapidly, and substantially completely remove from the interior and weld region, any oxygen or other possible deleterious gas or material. Subsequently a lower pressure introduction of gas will serve to maintain the interior free of oxygen and the like.
    Type: Grant
    Filed: September 7, 1982
    Date of Patent: June 12, 1984
    Inventor: Thomas C. Riley
  • Patent number: 4434348
    Abstract: A tungsten electrode (35) is positioned adjacent the root face (15) of a tube (10) with the tube and the electrode being connected to a source of direct current (40) such that the electrode is positive with respect to the tube. The electrode is mounted in an assembly (30), and the assembly is provided with a shielding gas from a source (48). The electrode assembly is mounted for rotation on an orbiting head (60) with the electrode axially spaced from the root face. As the electrode is rotated about the tube, the root face (15) and a portion (20) of the inner surface and a portion (25) of the outer surface are simultaneously cathodically cleaned. Preferably, the electrode (35) cleans the root face from two to four times in preparation for a subsequent welding operation.
    Type: Grant
    Filed: January 18, 1982
    Date of Patent: February 28, 1984
    Assignee: Hobart Brothers Company
    Inventor: Gary L. Reid
  • Patent number: 4424436
    Abstract: A crucible for containing molten magnesium, and a process for forming the crucible. The crucible is formed from ferritic stainless steel, and particularly type 444 stainless steel plate. The method involves forming ferritic stainless steel plate into component parts of the crucible, while maintaining the ferritic stainless steel plate at temperatures above about F. but below the "blue brittle" temperature range. Further, the method involves special techniques for welding the crucible parts. Specifically, the crucible parts are preheated to a temperature of C. and are completely welded by a process utilizing multiple welding passes with a special metal inert gas shielded welding technique before any cool down of the crucible parts below C. is allowed. The welds extend completely through the crucible walls, which are the thickness of steel plate, and completely incorporate the crucible parts while being essentially free of cracks.
    Type: Grant
    Filed: December 24, 1981
    Date of Patent: January 3, 1984
    Assignee: American Tank & Fabricating Company
    Inventor: Kenneth J. Humberstone
  • Patent number: 4408112
    Abstract: The method of and apparatus for welding of a pair of in-line pipes which utilizes a pair of insert rings. Initially, in the root area of the weld there is located an inner insert ring, which is welded to the pair of abutting pipes by a root welding path. An outer insert ring which is constructed of two identical pieces is located exteriorly about the inner insert ring between the pair of in-line pipes. The outer insert ring includes a laterally extending flange which is to be tack welded to the exterior surface of the pipe which is abuts. The main section of the outer insert ring is then melted to fuse together the pipes. The tack welding of the flange to the pipes keeps the main section of the outer insert ring located between the abutted edges of the in-line pipes.
    Type: Grant
    Filed: June 12, 1981
    Date of Patent: October 4, 1983
    Inventor: Gasparas Kazlauskas
  • Patent number: 4400611
    Abstract: When metal inert gas (MIG) welding is carried out at normal atmospheric pressure, the electrode is made positive with respect to the workpiece because the use of a negative electrode gives little penetration. In undersea welding, as the pressure increases the arc stability and metal transfer in MIG welding become erratic and there is copious fume evolution. According to the present invention, MIG welding at pressures greater than 7 bars is carried out with the electrode negative with respect to the workpiece and with an electrode wire of diameter not greater than 1.4 mm; the slope of the power supply, as seen from the welding arc, is preferably between 6 and 15 V/100 A, which is higher than the 3 to 4 V/100 A used in positive-electrode MIG welding at normal atmospheric pressure.
    Type: Grant
    Filed: November 14, 1980
    Date of Patent: August 23, 1983
    Assignee: The Welding Institute
    Inventor: Michael E. Wilkinson
  • Patent number: 4400605
    Abstract: A method of producing welded, thin-wall straight-seamed tubes comprises forming a strip in rolls of a tube-forming mill into a tube skelp, and then subjecting the latter to the inert-gas-shielded non-consumable electrode welding. The tube skelp is formed with a gap between edges being 1/500 to 1/30 to the tube-diameter-to-wall-thickness ratio, taken in mm. The rate of welding and the level of welding current are selected in accordance with the rate of heat release in the welding zone, which should be sufficient to close joint due to heat expansion of the tube skelp material and the formation of welding joint.
    Type: Grant
    Filed: November 6, 1981
    Date of Patent: August 23, 1983
    Assignees: Gosudarstvenny Nauchnoissledovatelsky, Proektny I Konstruktorsky Institut Splavov I Obrabotki Tsvetnyky Metallov "Giprotsvetmetobrabotka"
    Inventors: Jury F. Shevakin, Fikrat Seidaliev, Vladimir M. Tjushevsky, Jury V. Krasovsky, Erika D. Glebova, Valery K. Chivikin
  • Patent number: 4373125
    Abstract: A welding apparatus for pipes which provides for a guide means which is to be fixedly secured to the pipe adjacent the welding area, a first carriage and a second carriage is movably supported upon the guide means with each of the carriages supporting a pair of spaced apart welding heads. Attached to the guide means is a driving chain. Mounted on each of the carriages are motor means which, in turn, operate through the driving chain to move the carriages in a prescribed manner with respect to the guide means. The welding heads of each of the carriages move within the same plane but each are movable in a separate one hundred and eighty degree arc thereby forming a continuous circle. Associated with each welding head is a weld groove tracking system which automatically maintains each welding head correctly aligned within the welding groove. The entire apparatus of this invention, when combined with appropriate electronic computer equipment, automatically welds an adjoined pair of piping sections.
    Type: Grant
    Filed: July 22, 1977
    Date of Patent: February 8, 1983
    Assignee: Astro-Arc Company
    Inventor: Gasparas Kazlauskas
  • Patent number: 4371775
    Abstract: The invention relates to a method and an apparatus to perform plasma welding, by providing a cooling water temperature detector at the inlet side of cooling water in the plasma welding torch, controlling the temperature at the inlet side of the cooling water running into the plasma welding torch at a set temperature of more than C. and less than C., starting a plasma arc when the temperature of the cooling water reaches a specified point after starting to pass the cooling water, and moving the base metals and the torch relatively upon lapse of a specified time allowed to form a keyhole after start of the plasma arc.
    Type: Grant
    Filed: April 6, 1981
    Date of Patent: February 1, 1983
    Assignee: Kubota, Ltd.
    Inventors: Takao Mihara, Toshiaki Morichika, Shigenori Sone
  • Patent number: 4341938
    Abstract: A method of longitudinally seam-welding steel pipes comprises the steps of providing a conductive net-like enclosure tube around a cable for supplying a direct electric current from the power source to the welding head; and conducting a direct electric current through the enclosure tube and through the steel pipe in a direction opposite to that in which the direct current runs through the cable. Apparatus for longitudinally seam-welding steel pipes comprises an electrical cable coupled to a welding head, a net tube surrounding the cable, and a device for supplying a direct electric current to the cable in a first direction and to the net enclosure tube and steel pipe in the opposite direction. The direct currents flowing in the enclosure tube and in the steel pipe is adjustably controlled to minimize the magnitude of a magnetic field created around the net enclosure tube and producing a welded steel pipe seam.
    Type: Grant
    Filed: December 12, 1980
    Date of Patent: July 27, 1982
    Assignee: Nippon Kokan Kabushiki Kaisha
    Inventors: Hiroyoshi Matsubara, Kenji Takeshige, Tatsumi Osuka, Takashi Nagamine, Osamu Hirano, Jinkichi Tanaka, Itaru Watanabe, Motoaki Suzuki
  • Patent number: 4336436
    Abstract: A method and apparatus for welding girth joints in pipelines using two welding heads comprises the steps of moving each of the welding heads upwards around the pipeline along the respective section of the girth joint, feeding a welding wire to each of the welding heads so that the welding wire is fed substantially tangentially with respect to the surface of the pipe, and forming a circumferential weld by moulding it to hold the molten metal of the welding bath in the welding zone. An apparatus for carrying out the method for welding girth joints in pipelines comprises an annular track structure having at least two carriages mounted thereon which are connected with drives adapted to impart a translatory motion to the carriages. Each of the carriages carries a welding head provided with a welding wire feeder and a weld moulding member arranged opposite to the joint being welded.
    Type: Grant
    Filed: January 29, 1979
    Date of Patent: June 22, 1982
    Inventors: Vasily Y. Dubovetsky, Leonid N. Kopylov, Valentin A. Kotov, Jury I. Saprykin, Vladimir I. Slepchenko, Boris E. Paton, Igor K. Pokhodnya, Vladimir E. Paton, Mikhail G. Belfor, Efim Y. Leschinsky, Andrei N. Kutovoi, Mikhail R. Unigovsky, Veniamin S. Rotenfeld, Valery N. Shlepakov, Jury A. Gavriljuk, Alexandr G. Mazel, Mark Z. Sheinkin, Orest M. Serafin
  • Patent number: 4320277
    Abstract: Circular pipe of large diameter progressively formed of flat stock, the pipe having a single longitudinal seam is seam-welded by preparing welding grooves such that the inner groove is smaller in size and angle than the outer groove, sequentially carrying out submerged arc welding on the inner welding groove, and large current MIG welding to then first layer of the outer welding edge and a submerged arc welding to a second layer thereof.
    Type: Grant
    Filed: February 25, 1980
    Date of Patent: March 16, 1982
    Assignee: Nippon Kokan Kabushiki Kaisha
    Inventors: Tadaaki Taira, Kiyoteru Hirabayashi, Hiroyuki Ichinose, Osamu Hirano, Motoaki Suzuki
  • Patent number: 4314132
    Abstract: A weld and process for making same and usable in the arc-welding of cupro-nickel (ASME P.34) parts particularly pipe ends using a flux-coated stick electrode, characterized in that an "open V" butt weld is employed with a root face having a mean width greater than 1/16 inch (1.5 mm) and not greater than 1/8 inch (3.2 mm) and a root gap from 2 to 3 mm. The process is further characterized in that the welding is carried out solely from the open side of the V without employing additional inert gas shielding, backing material or subsequent welding at the reverse face.
    Type: Grant
    Filed: May 25, 1979
    Date of Patent: February 2, 1982
    Assignee: Grootcon (U.K.) Limited
    Inventor: Ronald Porter
  • Patent number: 4308446
    Abstract: A method and an apparatus for clearing burrs from products fabricated from metal stock. The burr of a product is used as one electrode, and another electrode is formed by extending an electrode material along, and apart from, the burr. A voltage is applied across the electrode to generate an arc between them. In the meanwhile, a magnetic field having a magnetic flux flow crossing the arc is formed to drive the arc along the burr by an electromagnetic force whereby the burr is melted and removed from the product.
    Type: Grant
    Filed: February 4, 1980
    Date of Patent: December 29, 1981
    Assignee: National Research Institute for Metals
    Inventors: Isao Okane, Sadao Fukushima, Kinji Tanuma
  • Patent number: 4302652
    Abstract: A method of welding the ends of submerged pipes in a gaseous atmosphere at any depth comprises isolating the ends of the pipes by introducing obturators therein and then introducing the pipe ends into an open topped receptacle which is capped with an underwater personal carrying intervention unit. The closed receptacle is filled with gas and then a sleeve is positioned between the ends of the pipes and welded to the pipes.
    Type: Grant
    Filed: June 6, 1979
    Date of Patent: November 24, 1981
    Assignees: Compagnie Francaise des Petroles, Etudes Petrolieres Marines, Ateliers et Chantiers de Bretagne - A.C.B., Compagnie Maritime d'Expertises, Compagnie Generale pour les Developpements Operationnels des Richesses Sous-Marines (Doris), Societe Nationale Elf Aquitaine (Production)
    Inventors: Philippe C. Nobileau, Rene M. Dermy, Guy J. Fleury
  • Patent number: 4294662
    Abstract: The invention concerns a process for the final assembly of a nuclear reactor vessel comprising two sub-assemblies which are brought together and welded along mating surfaces. At least three female centering stubs, each associated with a seat recessed relative to the outer surface of the stub, are provided on the mating surface of one of the sub-assemblies, and at least three male centering stubs, corresponding to the seats of the female stubs, are provided on the mating surface of the other sub-assembly, the positions of the stubs being registered relative to elements for positioning internal fitments of the vessel. The two sub-assemblies are brought together to engage the male stubs in the female stub seats and to bring projecting annular ridges on the mating surfaces into contact. A key is inserted into a socket defined by one of the pairs of stubs and the stubs are then joined to each other by point-welds.
    Type: Grant
    Filed: May 12, 1980
    Date of Patent: October 13, 1981
    Assignee: Framatome
    Inventors: Paul Guignard, Alain Commeau
  • Patent number: 4292492
    Abstract: Pipes are submerged - arc seam welded with a welding wire having a relatively high nickel content (about 6%), and low carbon content (<0.08%) to obtain a seam having a ductility and toughness which is still adequate for very low temperatures.
    Type: Grant
    Filed: May 6, 1977
    Date of Patent: September 29, 1981
    Assignee: Mannesmann AG
    Inventor: Karl Duren
  • Patent number: 4285460
    Abstract: Method and apparatus for double jointing pipe, wherein a first pipe section is moved onto a pipe support roller assembly and moved lengthwise over a boom which carries a pipe clamp and internal welder at its end. A second section of pipe is then moved onto the pipe support roller assembly and moved lengthwise into engagement with the first pipe section. After the first and second pipe sections have been properly aligned and the clamps expanded to hold the pipe sections in welding positions, the pipe sections are rotated simultaneously while both internal and external welds are made simultaneously. A cap weld may also be formed with the pipes clamped as described, or the pipes may be moved to another support roller assembly and the cap weld made while the connected pipe sections are on the second support roller assembly. The methods and apparatus disclosed result in considerable savings as to both the cost of equipment and operating costs.
    Type: Grant
    Filed: August 13, 1979
    Date of Patent: August 25, 1981
    Assignee: Midcon Pipeline Equipment Co.
    Inventor: Edward A. Clavin
  • Patent number: 4283617
    Abstract: Apparatus and method for rapid and automatic welding of joints which interconnect sections of pipe, and in particular oil or gas transmission pipe. The system includes at least one torch transport assembly which simultaneously moves one or more welding torches along a path parallel to the joint being welded. Selected operating parameters such as preheating power for the filler wire, of each welding torch are adjusted to accurately position each torch with respect to the joint, and to repeatably provide programmed welding parameters resulting in a uniform joint weld. The present system is disclosed in the context of hot-wire gas-tungsten arc welding torches.
    Type: Grant
    Filed: March 19, 1979
    Date of Patent: August 11, 1981
    Assignee: Merrick Welding International, Inc.
    Inventors: George J. Merrick, George E. Cook, Donald D. Modglin
  • Patent number: 4280040
    Abstract: A method for manufacturing a gas turbine combustion chamber that preserves cooling fluid holes therein. Passages are formed in one surface of each of two metal sheets. A plurality of cooling fluid holes are drilled through the passages to the other surface of each sheet. The two metal sheets are abutted face-to-face so that their respective passages form channels and the sheets are thereafter brazed together. The brazed sheets are bent to form an annular shaped chamber having a butt joint running along the length of the chamber. The butt joint is electric-arc welded along each side of the same, there being only partial penetration by each weld thereby avoiding the filling in of any of the cooling fluid holes, in the line of the weld, with melted material.
    Type: Grant
    Filed: March 22, 1979
    Date of Patent: July 21, 1981
    Assignee: Rolls-Royce Limited
    Inventor: John J. Gilkison