Abstract: A method for obtaining a vertical or horizontal profiled element for the interconnection of plasterboard panels to walls, in particular to plasterboard walls that can be applied to in-wall frames for retractable sliding doors or for the provision of drywall dividing walls. The method entails a continuous machining of a metallic lamina by punching or drawing or rolling obtained by using two rollers, one acting as a die and the other acting as a punch, so as to obtain on the metallic lamina a plurality of holes, which are uniformly distributed according to a series of mutually parallel rows.

Abstract: Embodiments of the present disclosure are directed to coiled steel tubes and methods of manufacturing coiled steel tubes. In some embodiments, the final microstructures of the coiled steel tubes across all base metal regions, weld joints, and heat affected zones can be homogeneous. Further, the final microstructure of the coiled steel tube can be a mixture of tempered martensite and bainite.

Abstract: A system and method is provided that authenticates a user using hybrid biometrics information, such as a user's image information, a user's voice information, etc. The user authentication method includes: acquiring a number of biometrics information; generating a number of authentication information corresponding to the acquired biometrics information; and performing an integral user authentication based on the by generated authentication information.

Abstract: A heater plate for butt fusion of polyolefin pipe has concentric rings, each with an array of radial bores containing cartridge heaters, and a concentric cavity between the rings to carry wiring from the cartridge heaters. The inner ring components are symmetrical to provide a foundation for uniform surface temperature distribution across the entire area of the inner ring. The outer ring components are coordinated to counterbalance the heat sinks resulting from their asymmetrical configuration so as to increase the likelihood that the uniform surface temperature distribution foundation established for the entire area of the inner ring can be maintained and so that the total diameter of the heater plate, including the outer ring, can be used in fusing pipe.

Abstract: A method for creating an improved coiled tubing is provided, comprising cleaning a sheet metal workpiece using an electroplasma process to remove oxide scale and other contaminants on surfaces of the workpiece; applying a first metal coating to the workpiece using the electroplasma process; forming the sheet metal workpiece into a tube having abutting edges to form a seam; welding the seam to complete the formation of the tube; grinding the seam to establish a smooth exterior surface on the seam; applying a second metal coating to the seam of the tube using the electroplasma process; and coiling the tube around a spool.

Abstract: A squeeze roll stand includes a combination of a fixed portion installed at a joint position of an electric resistance welded pipe manufacturing line, in which squeeze rolls excluding left and right upper rolls are detachably assembled, and a movable portion overlying the fixed portion, inside which left and right upper rolls are detachably assembled, the movable portion being inclined, taking a back surface downstream side as a fulcrum point, toward a same side from an assembling position on the fixed portion to a retreat position to open an upper part of the fixed portion. The movable portion is driven and reciprocated between the assembling position and the retreat position with cylinder type actuators as a drive mechanism. At the retreat position, the movable portion overlies a bead grinding device arranged on the back surface downstream side of the fixed portion with a front surface facing upward.

Abstract: A method is provided for producing a pipe from a band which has a layer of a first metal and a layer of a second metal, the layers being metallurgically bonded to one another over the entire length of the band. Along the two longitudinal edges of the band, the first metal is removed from the second metal in strips which run over the entire length of the band. The band is formed into the open-seam pipe with the first metal located on the outside, and the abutting edges of the layer of the second metal are welded to one another forming a pipe which is closed all the way round. In the region of the weld seam, a layer of the first metal is then deposited on the second metal to produce a pipe with a layer of the first metal which is closed all the way round.

Abstract: Provided is a submerged arc welding method for a steel plate. In welding the steel plate from an internal surface or an external surface by a submerged arc welding, welding condition is set such that, a cross-sectional area of internal weld metal S1 and a cross-sectional area of external weld metal S2 satisfy the formula (1), the formula (2), and the formula (3), that is, 0.40?(S1+S2)/t2?0.80 . . . (1), S1/t2?0.35 . . . (2), and S2/t2?0.45 . . . (3), wherein t is a plate thickness of the steel plate (mm), S1 is a cross-sectional area of the internal weld metal (mm2) excluding the cross-sectional area of a portion of the internal weld metal overlapping with the external weld metal after external welding, and S2 is a cross-sectional area of the external weld metal (mm2).

Abstract: A machine for continuously forming square tubes includes, in sequence, forming stations suitable for progressively bending a sheet strip, at least one finishing station suitable for further approaching the edges of the bent sheet strip for the final welding and at least one station for closing the square tube. In a forming station, the axes of rotation of the lower rolls of each pair of forming rolls are horizontal and aligned to each other. Each finishing station includes an idle forming roll placed below the square tube being formed; two idle forming rolls, placed at the sides of the square tube being formed, performing movements in opposite directions, parallel to the plane of the sheet strip and two idle forming rolls placed above the square tube being formed, performing movements orthogonal to the plane of the sheet strip.

Abstract: The invention relates to a method of connecting of strips to an endless strip with a clamping arrangement (110, 120) with a clamping device (110-r, 120-r) on the inlet side and a clamping device (110-1, 120-1) on the outlet side, a cutting arrangement (155) with an upper cutter (150) and a lower cutter (130) and with a joining arrangement, wherein in a first step the clamping devices are opened and two strip ends are introduced, and in a subsequent step in the next step the strip ends are introduced, and in a subsequent step in the next step the strip ends are cut by means of the cutting arrangement, before they are moved into a joining position and are joined there.

Abstract: A flat tube includes a pair of upper and lower walls opposed to each other, two side walls interconnecting the upper and lower walls at left and right opposite side edges thereof, and a covering wall provided over the outer surface of the left side wall and brazed to the left side wall. The left side wall is made from a side wall forming portion projecting downward from the upper wall integrally therewith and a side wall forming portion projecting upward from the lower wall integrally therewith by brazing these portions as butted against each other. The covering wall is made by folding a covering wall forming portion formed by extending one side edge of the upper wall. The left side wall including the wall forming portion of the upper wall and the wall forming portion of the lower wall can be protected.

Abstract: The invention relates to a device (1) for cutting or welding tubes (3) or similar workpieces, said device comprising a guiding mechanism which is used to control the cutting or welding torch (17) along a pre-determined line and is provided with a stand-type portal (7). Said portal comprises a through opening (8) into which the workpiece (3) to be machined can be guided in the axial direction. A rotary part (14) can be rotated about the axis of the through opening (8) in a motor-driven manner, guiding a holding arm (16) therewith, which carries the cutting or welding torch (17) on the free end thereof. Said holding arm (16) is fixed to the rotary part (14) and embodied in such a way that the cutting or welding torch (17) moves radially in relation to the axis of the through opening (8) and can be brought into various angular positions in relation to the surface of the workpiece (3).

Abstract: A process for producing high pressure tubing from austenitic stainless steels. The process entails passing a continuous austenitic stainless steel strip through pre-weld rolls enclosed in a forming housing to produce a continuous tubular shape having opposing edges separated by a longitudinal gap. While the gap is maintained with a seam guide and a liquid-free gas mixture of an inert gas and a gaseous flux is directed at the gap and into an interior of the tubular shape, the tubular shape is caused to pass through a high frequency induction coil to cause heating of the opposing edges of the tubular shape. Pressure is then applied to the tubular shape with weld rolls to force the opposing edges together and form a continuous tubing having a continuous butt weld joint. The weld joint is then quenched with an inert gas without the assistance of a liquid coolant.

Abstract: A system and method of forming a continuous strip from a plurality of strips, each strip having a leading end and a trailing end. Embodiments can include a forming apparatus that chamfers at least one of the leading and trailing ends of each strip. The chamfered trailing ends may then be positioned against chamfered leading ends of successive ones of the plurality of strips. Once a leading end and a trailing end are positioned against one another, a first welding apparatus may weld on a first side, from above, the trailing and leading ends positioned against each other to form weld joints. Once at least two strips have been welded together, the strips can constitute the continuous strip. An inverting apparatus can then invert the continuous strip and weld joints. The inversion of the weld joints can be done so as not to create a reverse bend in the continuous strip. A second welding apparatus can then weld on a second side opposite the first side, from above, the inverted weld joints to form weld junctions.

Abstract: The invention relates to a method for changing sets of top rolls, lateral rolls, and a bottom roll, and mounted in chocks of a welding stand of a continuously operating longitudinal tube welding machine. The inventive method enables the rolls to be changed faster, using less appliances. Said method comprises the following steps: the top rolls are lifted; a dismantling/transport means is placed beneath the top rolls; the top rolls are lowered onto the dismantling/transport means and deposited on the same; and, once the top rolls have been removed, the dismantling/transport means is laterally withdrawn.

Abstract: Process for producing a tubular component which comprises sections which are intentionally different from one another with regard to one or more aspects selected from the group consisting of aspects including material, thickness, size, more specifically circumference or diameter, and the like, and hydroforming of the component, in which process the component is produced by rolling up a substantially flat sheet, which flat sheet substantially corresponds to a flat blank of the tubular component.

Abstract: A method of manufacturing loading plane border frame tubes for chairs utilizes continuous roll-forming processes to roll a base material to form loading plane border frame tubes for use on chairs. The processes include: transport a steel sheet to a roller leveler for flattening; then roll the steel sheet through a first roller calender, a second roller calender, a third roller calender, and a fourth roller calender to form a semi-finished tube; send the semi-finished tube to a high frequency generator for welding and soldering at high temperature; trim the semi-finished tube in a trimming machine; and roll the semi-finished tube through a fifth roller calender to form a finished tube of a selected shape for making border frames of loading planes of the chairs.

Abstract: In a process for producing longitudinally welded tubes, a metal strip, which is continuously pulled from a supply, is gradually formed into a slit tube and the longitudinal slit of said slit tube is welded. The metal strip (2) is pulled through a plurality of drawing dies (8, 9, 10, 11) arranged one behind the other and having a diameter that decreases in production direction, and in each of the drawing dies (8, 9, 10, 11) is increasingly bent in circumferential direction. The slit tube is closed in a last forming step (15) immediately in front of the welding point.

Abstract: An apparatus and method for welding a shaft having an open seam defined between opposed longitudinal edges. The method comprising passing the shaft along its longitudinal axis through an array of pressure rollers which contact the surface of the shaft at a plurality of discrete points and compress the shaft by applying inwardly directed radial forces to the shaft. An electrical resistance welding assembly welds the seam while closed by the pressure rollers.

Abstract: A method for smoothing and compacting a weld on a cylindrical support sleeve includes mounting the support sleeve on an abutment and moving a device across the support sleeve such that a roller on the support sleeve rolls on the weld under pressure so that it smooths and levels the weld. An arrangement for smoothing and compacting a weld on a cylindrical support sleeve includes, the abutment on which the support sleeve may be mounted, the device, and the roller.

Abstract: Triboelectric sensors which generate electrical signals in response to mechanical disturbances creating relative motion of conducting and dielectric components of the sensor are fabricated from thin metal foil which is plastic-coated on one side and which can be formed into elongated, cable-like sensors having a variety of other shapes and sizes. The foil encloses one or more wire-like inner electrical conductors which, may be sealed within the envelope formed by the outer foil by heat-sealing the plastic-coated foil. A technique similar to welding may be used in which electrodes are placed in contact with opposing faces of the metal foil and an electrical current is passed though the foil. Local heating of the foil and of the plastic coating near the point of contact of one or both electrodes can cause the plastic to melt and the opposing plastic faces to bond together.

Abstract: An apparatus and method for leveling the clamping surface to obtain proper heat sink for narrow strips in a coil end joiner which includes a coil material support table and a retaining plate which is positioned against the upper surface of the coil material to be joined by, for example, one or more air cylinders. A weld clamp leveler is also provided which is adjustable to provide a preselected offset between the coil material support table and the retaining plate in a forward portion of the coil material support table. The weld clamp leveler is preferably used when relatively narrow coil material is being joined to preclude tilting of the retaining plate relative to the coil material support table and the coil material being joined and is preferably adjusted to provide approximately the same offset between the coil end support table and the retaining plate as the thickness of the coil material being joined.

Abstract: A forming stand for continuously forming a skelp material into a pipe, by pressure of spaced-apart forming rolls supported by spaced upper and lower shafts, the forming rolls having two portions, with one portion fixedly fitted on one side of its shaft, a sleeve slidably fitted to the other end of the shaft and fixedly secured to the sleeve and slidable with respect to the shaft; a bearing box for supporting one side of the associated shaft; a bearing box supporting the other side of the associated shaft through the sleeve; upper and lower stand supporting frames for supporting both of the bearing boxes to be movable in an axial direction; and supporting columns for supporting the stand supporting frames; the pipe-forming force is continuously measured and the forming operation is adjusted such that the measured value of pipe-forming force does not exceed a predetermined pipe-forming upper limit.

Abstract: To weld a workpiece rounded from plane metal sheet on a seam welding machine, the workpiece is introduced into a preform (7) whose internal shape is approximately the same as the workpiece. Stops (11, 12, 14) are used to fix the workpiece in place in the preform, and the workpiece is then moved together with the preform (7) towards the welding rollers and welded. To this end the preform (7) is arranged on a platform (6) which in its turn is arranged on a movable carriage (3) in the welding machine (1). Welding with the preform makes it possible to weld together any desired sheet metal workpieces, including those which are not uniformly rounded because, for example, they are formed from blanks incorporating recesses.

Abstract: During the production of long metal tubes with small diameters, where a metal tape is drawn from an annular coil, is gradually formed into a tube with a longitudinal slot and the longitudinal slot is welded, the internally and externally located metal tape ends of a number of annular coils are interconnected by welding, and the annular coils are horizontally positioned on tension rings which are attached to a rotatable take-up drum. The metal tape with the welded ends is drawn off without interruption.

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.

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 method for manufacturing a sweeped tubular bumper reinforcement member having a rear wall formed with an inwardly indented portion in cross-section and a front wall formed in parallel with the rear wall and welded to the inwardly indented portion of the rear wall.

Abstract: A device for the inside scarfing of tubes or profiles longitudinally welded in a tube welding line consists of a tool carrier guided on guide rollers inside the tube to which a cutting ring is attached. The cutting ring is clamped in a cutting ring holder and can be rotated about its central axis which is inclined at an acute angle to the longitudinal axis of the tube. The cutting ring can be retracted from the cut, whereby at the same time as the retraction of the cutting ring, the clamp can be released and the cutting ring can be turned further by a defined angle. The device is controlled by at least one hydraulic or electric line leading out from the welding point of the tube or profile in the tube welding line.

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.

Abstract: In a method for producing internally grooved tubes for heat exchangers, a smooth metal tape is drawn from a circular supply, a rolling mill provides it with a number of grooves that are parallel to each other and run at an angle of 15.degree. to 45.degree. with respect to the lengthwise direction of the tape, the tape is continuously formed into a tube with a lengthwise slot, and the slot is welded. At least two groups of parallel grooves are rolled into the surface of the metal tape so that the grooves form a herringbone pattern.

Abstract: A metallic strip having at least one surface enhanced with a texture pattern is formed into a welded tube. A fin insert shapes the edges of the metallic strip prior to welding and minimizes the formation of a protruding weld bead. The longitudinally running edges of the metallic strip adjacent to the enhancement are angled so that the unenhanced portions of the strip edges contact during welding. By having the unenhanced portions contact, fluctuations in metal volume during welding are reduced. This reduces weld instability.

Abstract: A composite small-diameter tubing resistant to interaction with materials conveyed therethrough such as liquids containing alcohols or corrosive agents which includes a cylindrical outer metal conduit having a hollow central shaft extending longitudinally therethrough defined by an interior wall; and a continuous non-reactive interior tube surrounded by and positioned within the cylindrical metal conduit. The tubing can be manufactured by a process which includes the steps of a) positioning a length of non-reactive tubing having a predetermined outer diameter within an inner diameter of metal tubing of essentially corresponding length, the metal tube having an unsealed side seam, wherein the inner diameter is greater than the outer diameter of the non-reactive tubing; and b) sealing and reducing the metal tubing to an outer diameter essentially equal to the predetermined outer diameter of the interior tubing. The non-reactive interior tube may be made of a suitable polymeric material.

Abstract: The method of forming a coated seamed metal tube of this invention is particularly, but not exclusively adapted to existing continuous tube forming mills, wherein the tube is formed from a metal strip and welded with the seam located in an upper portion of the tube. In the process of this invention, at least one surface of the strip is coated with a metal coating prior to forming and welding. The tube is then turned to relocate the welded seam in a lower portion of the tube and the lower portion of the tube is then reheated to melt the metal coating and the metal coating then flows downwardly over and coating the welded seam. In the most preferred continuous or in line process of this invention, the tube is continuously spirally twisted following welding to locate the seam in a lower portion of the tube adjacent a heater and the tube is then heated by the heater to the melting temperature of the metal coating, causing the coating to coat the seam.

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.

Abstract: An improved steel tube made from low sulfur steel wherein clean steel flat strip is formed into a circular form with its edges abutting and the edges are heated and pushed together to form a welded tube. The inside and outside beads are removed with cutting tools.

Abstract: The can body to be welded in a welding station is shaped by gradually bending flat metal sheets zone by zone along a linear conveying route until the can body has been shaped. This linear conveying route at the same time leads to the welding station. In this manner can bodies can be produced and welded at a fast rate.

Abstract: A welding management apparatus for use with a tube production machine. A workpiece fed from a roll of metal strip is formed in a tubular formation having side surfaces opposite to each other. An upsetting pressure is applied to joint the opposite side surfaces of the workpiece at a jointing point. A high frequency power is supplied to the workpiece to weld the opposite side surfaces at the jointing point so as to produce a metal tube member. The welding management apparatus comprises a camera positioned to have a visual field including the jointing point for producing a video signal indicative of an image including an area luminous with a pre-arc produced in the visual field. An image processor converts the video signal into a luminance distribution pattern. An inference unit is provided for inferring a defective welding condition based upon the luminance distribution pattern. The inference unit includes an alarm unit for producing an alarm when a defective welding condition is inferred.

Abstract: The method of forming a seamed metal tube having a metal coating of this invention includes galvanizing the strip prior to welding. The strip is then formed into an open seam tube and welded in an inert atmosphere with the seam located in the lower portion of the tube. Finally, the metal coating is caused to flow downwardly over the seam, coating the seam by several means. In one embodiment, the strip is preformed into an arcuate shape and galvanized, wherein the zinc coating increases in thickness toward the lateral strip edges, such that the coating will flow over the seam following welding. The tube may also be reheated following welding, preferably in an enclosure containing an inert atmosphere which includes the weld apparatus. In another embodiment, an inert gas is directed over the inner and outer surfaces of the tube, adjacent the seam, driving the molten metal downwardly over the seam to coat the seam.

Abstract: A composite small-diameter tubing resistant to interaction with materials conveyed therethrough such as liquids containing alcohols or corrosive agents which includes a cylindrical outer metal conduit having a hollow central shaft extending longitudinally therethrough defined by an interior wall; and a continuous non-reactive interior tube surrounded by and positioned within the cylindrical metal conduit. The tubing can be manufactured by a process which includes the steps of a) positioning a length of non-reactive tubing having a predetermined outer diameter within an inner diameter of metal tubing of essentially corresponding length, the metal tube having an unsealed side seam, wherein the inner diameter is greater than the outer diameter of the non-reactive tubing; and b) sealing and reducing the metal tubing to an outer diameter essentially equal to the predetermined outer diameter of the interior tubing. The non-reactive interior tube may be made of a suitable polymeric material.

Abstract: The present invention is a machine for manufacturing welded steel pipes, in which an edge bending roll for constraining under pressure a strip from its pipe edge portions to the boundaries between the pipe edge portions and its pipe side portions to bend the strip, a first center bending roll for constraining under pressure the pipe side portions to bend the pipe side portions, second to fourth center bending rolls for constraining under pressure the strip from the boundaries between the pipe side portions and its pipe bottom portion to the pipe bottom portion and applying lateral pressure to the pipe from both sides to bend the boundaries and the pipe bottom portion and a plurality of cage rolls arranged on both the sides of these center bending rolls, first and second fin pass rolls for further forming under pressure the pipe, are arranged in order from the stream side to the downstreamside of a roll forming process.

Abstract: A method and apparatus for transferring tubular products from one mill to another including a connecting table having the shape of a reverse curve. The table includes a base and two spaced apart walls attached to the base defining a passageway between the base and the sidewalls. A diverter is associated with the connecting table to divert metal product in a hot working state from a first conveying table onto the connecting table leading to a second conveying table. The connecting table preferably is associated with a welding and forming mill and a stretch reducing mill.

Abstract: Steel strip (1) is cleaned by shot blast machine (3) and its upper surface is coated with zinc in molten plating device (4). The strip is formed by roll forming machine (6) into a tube and the outer surface of the tube is coated by plating device (11).

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.

Abstract: A process for the continuous manufacture of seamless tube by confining a selected length of metal strip in the form of a tube and with at least two longitudinal abutting edges and completely melting a selected length of such tubular form to form a seamless tube and cooling the formed seamless tube. The cooling is preferably in a controlled atmosphere of nitrogen and the temperature is reduced to about 700.degree. F. before further processing takes place. In a preferred process the material is a single strip of metal formed into a tube with only one longitudinal seam and it is moved continuously through a mould heated by induction heating selectively controlled to cause the tube to preheat to a selected temperature and then be subjected to a temperature bringing the metal to its molten state to form a seamless tube and while the seamless tube is moving it is cooled downstream from the melting zone solidifying the metal and bringing it to a selected temperature before exiting the mould.

Abstract: An apparatus for forming metal tubes is shown in which a metal strip 2 is passed through the apparatus and is formed by a combination of rollers 17, 17', 19, and dies 15, 24 into a shape defining a tube. Prior to the completion of the formation of the metal strip 2 into a shape defining a tube, a brazing wire 1 is supplied through rollers 8 onto the metal strip 2 between two edge portions thereof to be bonded together. The edge portions are bonded together by means of a frictional wheel 27 rotating at high speed.

Abstract: An improved method of manufacturing galvanized steel tubing from steel strip having at least one galvanized surface, which surface becomes the exterior surface of the tubing is provided. In the method of the invention, after the steel strip is roll-formed and welded to complete the tubing and the welded seam is scarfed to remove irregularities, a quantity of an acid solution is applied to substantially only the scarfed area to react with oxidized metal, and the rinsed, leaving the non-scarfed galvanized exterior surface intact. The tubing is then heated to a temperature sufficient to cause the galvanized coating of the exterior surface to begin to flow and the tubing is regalvanized to produce an improved galvanized exterior surface, which is resistant to cracking along the scarfed area.

Abstract: An improved method of manufacturing galvanized steel tubing from steel strip having at least one galvanized surface, which surface becomes the exterior surface of the tubing is provided. In the method of the invention, after the steel strip is roll-formed and welded to complete the tubing and the welded seam is scarfed to remove irregularities, a quantity of an acid solution is applied to substantially only the scarfed area to react with oxidized metal, and then rinsed, leaving the non-scarfed galvanized exterior surface intact. The tubing is then heated to a temperature sufficient to cause the galvanized coating of the exterior surface to begin to flow and the tubing is regalvanized to produce an improved galvanized exterior surface, which is resistant to cracking along the scarfed area.

Abstract: A tube weld mill comprising a plurality of successively disposed roll stands to form a strip to a desired generally tubular configuration and a weld means to weld together the adjacent edges of the thus formed strip, each roll stand having a pair of co-operating rolls, a drive transmission to transmit a rotary drive from a driving means to each of said rolls, means removably to secure at least one of said roll stands to a base, means to disconnect said drive from the roll stand to permit of removal of a roll stand from the base and replacement by the same or another roll stand and the drive transmission permitting said disconnection to be performed at a fixed location independent of variation in the separation of the axes of rotation of the rolls of the roll stand.

Abstract: The method of forming a seamed metal tube having a metal coating of this invention includes galvanizing the strip prior to welding. The strip is then formed into an open seam tube and welded in an inert atmosphere with the seam located in the lower portion of the tube. Finally, the metal coating is caused to flow downwardly over the seam, coating the seam by several means. In one embodiment, the strip is preformed into an arcuate shape and galvanized, wherein the zinc coating in creases in thickness toward the lateral strip edges, such that the coating will flow over the seam following welding. The tube may also be reheated following welding, preferably in an enclosure containing an inert atmosphere which includes the weld apparatus. In an other embodiment, an inert gas is directed over the inner and outer surfaces of the tube, adjacent the seam, driving the molten metal downwardly over the seam to coat the seam.