Abstract:
The invention comprises a method and apparatus for maintaining seam alignment in seam welded tubes comprising the tube being formed to be advanced through a shaping station after seam welding and prior to the cooling of tube wherein the tube is preformed to commence to assume at least two continuously extending flat shaped surfaces parallel with the continuous seam and contacting the preformed tube subsequent to the cooling to maintain alignment of the weld seam.
Abstract:
A plant for producing metal heat exchanger tubes with spiral heat exchanger ribs secured to the exterior surface from smooth tubes and strip-form flat material for the ribs. In order to allow ribbed tubes to be economically produced at any desired location, the main plant units needed to produce the ribbed tubes, such as a rotating device, strip conveyor and joining device, are installed in one or more mobile container-type modules in production order.
Abstract:
A lightweight, portable clamping device assists in holding and reforming pipes in piping systems. The clamping device comprises a pair of semicircular clamp halves which are placed on the abutting ends of out-of-round pipe. The clamp halves are drawn together by tightening bolts on either side to align and reform the ends of abutting pipes. The clamping device can also be used to shape and hold the end of a single piece of pipe. A plurality of access ports around the perimeter of the device allow a welder to tack weld the ends of abutting pipes prior to welding.
Abstract:
The method of forming a seamed metal tube having a metal coating of this invention includes applying a metal coating to the upper face of a metal strip prior to welding. The strip is then formed into an open seam tube and welded, preferably in a non-oxidizing atmosphere with the seam preferably located in the lower portion of the tube. Finally, at least a lower portion of said tube is reheated with the seam located in the lower portion of the tube, thereby causing the metal coating to flow downwardly over the seam, coating the seam. In one embodiment, the strip is preformed into an arcuate shape and coated, wherein the metal coating increases in thickness toward the lateral strip edges, such that the coating will flow over the seam following welding. The inside coated seamed tube may also be immersed in a galvanizing or metal coating bath to coat the outside of the tube. In a preferred embodiment, the inside and outside coatings comprise substantially the same metal and a single galvanizing bath apparatus is used to coat the inside and outside surfaces of the seamed tube. In another embodiment, the coating on the inner surface of the seamed tube has a melting temperature substantially below the melting temperature of the metal strip, but higher than the melting temperature of the outside metal coating. In another embodiment, a lance is provided having a free end which extends through the adjacent lateral edges of a tube-shaped strip and a nozzle which applies metal coating material over the seam. A control loop is also disclosed for improved reflow of the metal coating over the seam.
Abstract:
A process for buttwelding metal workpieces having bevelled joint preparations using an automatic GTAW welder using filler wire includes preparing the bevelled workpiece with bevelled joint areas having minimal land thickness at the root extremities; placing the prepared workpiece joint sections together with an open gap between their adjacent root extremities, the gap having a minimum dimension that avoids harmful compression stress between the workpieces due to weld shrinkage and a maximum dimension that avoids filler wire penetration of the gap; fusion welding the open root area of the adjacent workpieces with a root pass weld using an automatic GTAW welder supplied with filler wire and a shield gas including 1 to 10% hydrogen and the balance inert gas; and then promptly overlaying the root pass weld with at least one additional filler weld pass using an automatic GTAW supplied with filler wire and hydrogen-free shield gas.
Abstract:
A dual bias weld is an improved weld for joining strips to be formed into coiled tubing. Tubing is formed from a first strip and a second strip, the first and second strips being of the same width. A planar end surface is formed on an end of the first strip, the plane of the planar end surface being defined by a line lying along a top surface of the first strip at an acute angle with respect to the longitudinal direction of the first strip and a line lying along an edge surface of the first strip at an acute angle with respect to the longitudinal of the first strip. Similarly, a planar end surface is formed on an end of the second strip, the plane of the planar end surface being defined by a line lying along a top surface of the second strip at an acute angle with respect to the longitudinal direction of the second strip and a line lying along an edge surface of the second strip at an acute angle with respect to the longitudinal direction of the second strip. A composite strip is formed by welding the planar end surface of the first strip to the planar end surface of the second strip to form a dual bias weld. Excess weldment is then removed from top, bottom and edge surfaces of the composite strip such that the width of the weld is identical to the width of the first and second strips. Coiled metal tubing is then formed from the composite strip.
Abstract:
An apparatus and method for resistance welding tubular parts. The apparatus includes a weld gun having electrodes with arcuate contact faces engaging the parts. The electrodes are displaceable relative to each other. The contact faces are designed to distribute the force applied to the parts to prevent deformation and to hold the parts together steadily in order to minimize the amount of undesired electrode displacement caused by these effects. A test computer monitors the amount of electrode displacement occurring as a result of penetration of the parts into each other during welding. When the displacement between the electrodes falls within a predetermined displacement range, which is indicative of a proper weld between the parts, the computer cooperates with a weld controller to terminate the welding power, thereby inhibiting any substantial further penetration of the parts. The apparatus and method is suitable for tube-to-tube and wire-to-tube applications commonly performed in the manufacture of automobile seats.
Abstract:
The process for assembling long sections (11) of booms of support legs of an oil platform comprises machining an inclined flat surface (15) on the whole of the length of each main face of a rectangular plate (12), machining a groove behind each flat surface (15), machining an inclined chamfer on longitudinal edges of a stiffener (13), placing a stiffener (13) on each main face of the rectangular plate (12), welding each stiffener (13) to the rectangular plate (12), under a vacuum from the exterior by means of an electron beam, in the region of the chamfers and the flat surfaces so as to produce a section (11), and heat treating the section (11).
Abstract:
A tubular shape finishing apparatus in a steel pipe manufacturing system which molds band steel in a tubular shape while passing through a plurality of sets of forming roll stands and welds the butt portion by a seam welding unit, the tubular shape finishing apparatus welding the pipe by a seam welding unit, cutting off padding by a bead cutter, finishing and shaping the same into a shape of a desired diameter, and to be about an complete round, and comprising one or two of 3-roll forcible drive type stand or 3 or more roll forcible drive type stands disposed in series.
Abstract:
A fixture for aligning clamping pipes end to end to enable joining the pipes by welding includes a collar circumscribing one of the pipes and circumferentially spaced arms extending outwardly from the collar and then coaxially with the pipes. Pipe damps are supported by each of the arms at approximately 120 degrees intervals about the pipe. The stems of the clamps are supported by the arms such that proper orientation of the clamping shoes and guide members is assured. Furthermore, an extension of the stem which projects between the pipes and carries an inner guide member for engagement with the inner circumferential surface of the pipe has a differential thickness such that the pipes are initially separated by a predetermined thickness by engagement of the pipes with the necked portion of the extension for tack welding. After tack welding is complete, the stems are rotated 90 degrees, thereby bringing a narrower dimension of the necked portion into registry with the gap between the pipes, permitting withdrawal of the stems.