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. In another embodiment, the lateral edges of the strip are formed with indentions or grooves directed toward the lateral edges which direct the molten metal downwardly over the seam.
Abstract:
A laser beam is directed toward a rotating metallic tube having a fin helically wound about and welded to its surface by a high frequency welding process. The laser beam generates heat in the tube to supplement the heat induced by resistance to electrical current flow to create a proper temperature in the tube for forge welding of the fin and tube.
Abstract:
An orbital welding head for joining two tubes positioned end-to-end includes a welding electrode which is rotated around the tubes and a pair of clamps for holding the tubes in the correct position with respect to each other and the welding electrode. The clamps include a fixed member, a rotatable member and a hinge assembly for joining the rotatable member to the fixed member. The rotatable clamp members are moved clear of the tubes when the tubes are either inserted into or removed from the welding head. Fluid channels are formed in both the fixed and rotatable clamp members. The hinge assembly connects the rotatable clamp member with the fixed member. Fluid channels within the hinge assembly allows cooling fluid introduced into the fixed member to be carried through that member into the rotatable member, cooling both. A return fluid channel is also provided by the hinge. The hinge is provided with a passageway for transferring cooling fluid from one rotatable clamp member to another. Because the rotatable clamp members are cooled, they can be opened by the operator without requiring the use of gloves.
Abstract:
A fitting for connecting elongate elements, such as tubing, comprises a body 1 and legs 2a and 2b which fit into tubes A and B. The legs 2a and 2b are provided with recesses 4 for receiving bonding inserts 5 which contain bonding medium, for example, solder 6. The inserts 5 are of a material compatible with materials of the tubs A and B. When heat is applied to the external surface of the tubes A and B, in the region of the legs 2a, 2b, the solder 6 melts and bonds the inserts 5 to the tubes A and B.
Abstract:
An adjustable length linear bus bar for conducting a current between an induction heating power supply and an induction heating coil. The bus bar includes a fixed bar having a channel formed along the length of the fixed bar and a movable bar having a portion formed to slidably fit inside the channel of the fixed bar. A hydraulic ram biases the slidable bar against the fixed bar to facilitate the transfer of current between the fixed and movable bars. A clam shell type of construction allows the inductor coil to be quickly moved into and out of a gap between a pair of articles being heated.
Abstract:
An electrical work-in-circuit heating tool for metal bonding especially in cramped locations where flame heating and tong-style tools are not usable. The tool comprises a hinged pair of spring-loaded arms having electrically insulating open-ended handles each of which contains a conductor bar within a grip portion thereof. The hinge comprises pivotally joined radial webs and the spring-loading is adapted to urge the distal ends of the arms toward each other. Each of the conductor bars is connected within an insulating grip portion of the handle to an electrical supply cable. At the distal end, each conductor bar carries a detachable electrode assembly that comprises a workpiece-contact member. A switch which is part of a low voltage power supply is removably mounted on the handle. Various configurations of electrode assembly are provided comprising different workpiece-contact members, such as a carbon block on each conductor bar, or a contact member on one bar and a ground clamp on the other.
Abstract:
A method and apparatus is disclosed for preparing the ends of large diameter metal pipe, such as that employed in cross-country pipelines, for welding of two pipe sections in end-to-end relationship with each other. Apparatus is provided for performing the method under which the pipe end to be prepared is first radially expanded uniformly around the entire circumference beyond its elastic limit to a predetermined diameter. While the expanding device holds the pipe end in this expanded position, a lathe aligned and associated with the expanding device is actuated to a machine beveled surface on the pipe end. Upon release and removal of the expansion mechanism, the pipe end remains in a permanently deformed truly circular configuration of a precisely predetermined diameter with the general plane of the pipe end accurately located in true perpendicularly to the pipe axis, thus enabling ends of a pair of adjacent pipe sections to be precisely aligned with each other around the entire pipe circumference in preparation for the welding of the two sections to each other.
Abstract:
A method and apparatus for high speed welding are disclosed wherein a continuous weld is formed at high speed along a member with a plurality of overlapping welds formed by pulses of high density energy from a pulsed high energy density welding device such as an electronically pulsed gas laser. The movement of the member being welded is detected in the vicinity of the pulsed laser. The pulsed laser is controlled in response to the detected movement so that the energy for welding from the pulses per unit length of the member being welded is accurately controlled. The control of the laser involves pulsing of the laser in response to the detected movement of the member so that the pitch of the overlapping welds along the member is substantially constant. Also, the power of the laser pulses is controlled and adjusted in a predetermined manner in response to the detected movements. The high speed movement of the member is detected by detecting the leading edge of the moving member at or upstream of the pulsed laser and also continuously detecting the position of the moving member at or as it moves past the pulsed laser. High quality welds can be made in materials at speeds of 22-40 m/min. or more with the method and apparatus.
Abstract:
A portable machine for electric arc welding and air carbon arc gouging on vertical wall surfaces is disclosed. A table-mounted carriage arm carrying a vertical positioning assembly for welding nozzles or a gouging torch is driven horizontally around a vertical axis of rotation while guide wheels on the carriage arm traverse the wall surface or traverse a flexible guide secured to the machine table through a system of support arms when a rough wall surface is involved. The carriage arm is biased yieldingly toward the wall surface during its horizontal traverse and the vertical positioning assembly adjusts itself automatically on its vertical axis to maintain proper welding nozzle and gouging torch alignment with the wall surface undergoing repair. A constant speed of movement of welding nozzles or a gouging torch across the wall surface is maintained. The welding nozzles or gouging torch are motor-driven vertically on the positioning assembly.
Abstract:
A fluid-to-fluid such as a liquid-to-air heat exchanger and a method of making such a heat exchanger in which there is provided a header plate, a plurality of liquid coolant tubes each extending into a hole in the header plate, a primary load bearing joint subject to the formation of leakage openings in the joint joining each tube to the header plate at its tube opening, and a thin sealant sealing against leakage any leakage openings that may be present or that may occur.