Abstract: A welding complex in accordance with the invention comprises a machine for resistance butt welding, means for supporting the end part of the pipeline and holding means including a platform reciprocable axially of the pipeline and a plate with a device for carrying the pipe section to be welded, rotatable by a drive between the positions of loading a pipe section and aligning it with the pipeline. For loading the holding means with the plate rotated into the loading position, by longitudinally displacing a pipe section from the accumulator, the latter is arranged alongside the platform, so that the pipe section it delivers extends at an acute angle relative to the end of the pipeline.

Abstract: The machine of the invention, intended for resistance butt welding of pipes, comprises two semi-housings mounted externally on the pipes to be welded to the opposite sides of a joint and interconnected by the flash and upset drive, a clamping device mounted in each semihousing, including radially arranged hydraulic cylinders with clamping shoes, and a control system of the hydraulic cylinders.The control system of the hydraulic cylinders includes control valve units structurally associated with the piston rods of the hydraulic cylinders. The control valve units include follow-up spool valves interconnected by their common actuator linkage.

Abstract: Disclosed is a machine for flash butt welding of pipes located in the bore of the pipes welded together, a housing (2) whereof is provided with rigidly attached thereto a first supporting disc (3) and a second supporting disc (4) and with a pipe flashing-and-upsetting means (5) which has a carrier (7) and a hydraulic actuator (6) for displacing said means along the housing (2) and also has two pipe clamping means (9, 10) each whereof is provided with a carrier (12 and 13) and self-contained hydraulic actuators (11) imparting axial motion to this clamping means.

Abstract: A mobile arrangement for laying a continuous pipeline comprises a resistance welding apparatus, an outer flash trimmer, and at least one pipe-laying means. A jib of the pipe-laying means has a longitudinal support structure suspended therefrom. A suspension is attached to this longitudinal support structure. The front end of said longitudinal support structure carries an outer flash trimmer, and the rear end of said longitudinal support structure carries an inductor for thermal treatment of the weld.

Abstract: An internal apparatus for flash welding pipes together in end to end relationship both under factory conditions and in the field, for example in laying trunk pipelines, comprises an elongate supporting member carrying an axially movable clamping assembly with electrode jaws for clamping one pipe, an axially immovable clamping assembly with electrode jaws for clamping the other pipe, and a doughnut-type welding transformer. The welding transformer is disposed at the side of the axially immovable clamping assembly, which is distant from the joint. The axially immovable clamping assembly is mounted on the elongate supporting member in a manner to provide an annular clearance therebetween such that there are extending therethrough two coaxial contact tubes, which are electrically insulated from one another and connect the welding transformer with the electrode jaws, whereby in operation a welding circuit is established.

Abstract: The arrangement comprises a body constructed in the form of a grip clamp arable from the vertical axis of a workpiece, and having two jaws coupled with each other in the upper portion thereof by a clamping cylinder. The arrangement further comprises cutters for deburring, and a mechanism for pressing said cutters to the workpiece surface. The cutters are mounted in the lower portion of the jaws so that cutting edges thereof form a profile of the workpiece cross-section. The cuttes disposed on the same jaw are pivotally connected with each other. The mechanism for pressing the cutters is constructed in the form of a system of hydraulic cylinders mounted on the jaws in symmetrical relationship relative to the vertical axis of the body. Said hydraulic cylinders are provided with rods operatively connected to corresponding cutters.

Abstract: Disclosed are welding current pick-ups which are switched into welding circuits. Outputs of these pick-ups are connected to inputs of a logical coincidence unit having its output connected to a control input of a welding program control unit whose output is connected with a drive adapted for moving the workpieces being welded.

Abstract: A pipe resistance butt welding apparatus comprises a body with an elongated arrying member and two internal expanding clamps including current-feeding shoes. One of the clamps is rigidly attached to the body, whereas the other is movably mounted on the elongated carrying member and connected with a drive intended to communicate reciprocating motion to the other clamp. A trimming mechanism for removing flash is mounted on at least one of the internal expanding clamps. The body of the apparatus mounts centering supporting rollers and driving wheels, the former and the latter being secured thereto by means of spring-loaded levers. The driving wheels are connected with a rotation drive intended to rotate the wheels. The body carries a powder cylinder and spring-loaded three-arm rockers, the latter being turnably mounted. The first arm of each of said three-arm rockers carries a driving wheel, the second arm carries an additional supporting roller, and the third arm is connected with a rod of the power cylinder.

Abstract: An apparatus comprises a body having V-shaped two-arm levers mounted thereon. Around the periphery of the body there are mounted cutting tool holders pivoted each to one arm of each of the levers. Secured to the body are drives for turning the levers and each connected with the other arm of each of the levers. On the front and rear ends of the cutting tool holders there are mounted rollers in contact with the inside surface of the pipe. Rigidly attached to the cutting tool holders are cutting tools.

Abstract: Surfaces of metal workpieces being welded are fused at a constant speed of feeding the workpieces towards each other, and the speed of feeding is, before the upsetting, increased to a final value thereof for a period of (1.0 to 4.0) (.DELTA.max/v.sub.1), where .DELTA..sub.max is the maximum gap between the workpiece surfaces being welded and v.sub.1 is the average speed of feeding the workpieces over the period of its increase. Empirical formulas are given to determine the maximum gap for workpieces of various thicknesses.

Abstract: A method consists in that the workpieces to be welded together are at first continuously moved towards each other with the welding current on and the ends of the workpieces are fused, the thermal state of the ends being monitored in terms of current, or of power, or of fusion time, or of length of the fused portion. After any of said variables has reached a preselected value which corresponds to the predetermined heating of the contact region, oscillatory movements are superimposed on the movement of one of the workpieces being welded towards the other and the fusion process is carried out till upsetting.

Abstract: A pipe resistance butt welding apparatus disposable within the pipes to be welded comprises a fixed expanding clamp and a movable expanding clamp, provided with clamping elements and actuating cylinders and intended to fix the pipes to be welded with respect to the apparatus. A cylinder to effect an axial movement of the movable expanding clamp is installed at the end at which this expanding clamp is located; the axial movement provides for drawing together the ends of the pipes to be welded in the course of fusion and upsetting. The cylinder for the axial movement of the movable expanding clamp is coupled with the actuating cylinder of the same clamp and with the clamping elements. The devices making up the apparatus and the cylinders are coaxially installed within a body wherefrom the clamp elements extend outwardly to engage the inner surface of the pipes being welded. Modifications of the apparatus for weld-joining of medium and large diameter pipes respectively are also described.

Abstract: Work pieces to be joined together by the flash butt welding method are brought together at a preset no-load voltage, the end faces of the work pieces are fused, and an upsetting is accomplished. The amount of the upsetting is determined within from 1.2 to 3.0 of the amount of the maximum gap between the end faces of the work pieces being welded together, which gap forms in the course of fusing the end faces of the work pieces. The maximum gap is determined from the following relation:.DELTA..sub.max =f(U.sub.o,.delta.),where:.DELTA..sub.max =maximum gap;U.sub.o =no-load voltage;.delta.=thickness of the work pieces being welded together.Empirical formulas to determine the maximum gap for work pieces of various thicknesses are presented.

Abstract: A pipe resistance butt welding apparatus comprises a movable clamp and a fixed clamp to locate the pipes to be welded. Current-feeding shoes contact the ends of the pipes to be welded together. A device is provided for axially moving the movable clamp in fusing and upsetting the pipes. Both clamps and the device are mounted on an elongated supporting member. The shoes are carried by beams oriented along the supporting member and having bevels acted upon by drive rollers, whose axes are directed across the supporting member. The invention is useful for welding large diameter pipes.

Abstract: The doughnut-type transformer comprises a spirally wound core consisting of several individual annular cores each tightened by rod members. The annular core is surrounded by transformer sections comprising the primary and the secondary windings. Each winding is composed of turns shaped as sectors in the plane of the transformer cross-section, a cooled turn of the secondary winding being placed between the turns of the primary winding in each transformer section. The turns of the windings surround the annular core so that the geometric center of each winding is displaced from the geometric center of the annular core in the cross-sectional plane thereof and the geometric center of the annular core is farther from the transformer axis.

Abstract: A welder arranged inside pipes to be welded comprises a housing with the longitudinal axis thereof matched with the axis of the pipes. On the housing are a welding transformer and two mechanisms clamping the pipes, each having a drive moving the mechanism along the axis of the housing, and each being electrically connected to the transformer. The housing has mounted thereon a pipe flashing and upsetting mechanism with its own hydraulic drive, kinematically coupled to one of the pipe clamping mechanisms, a hydraulic pump supplying fluid to the drives, and a mechanism driving the welder along the pipes' axis. The housing carries two bearing discs secured at opposite ends and three clips mounted on roller supports and movable along the housing's axis. Two clips are incorporated in the first and second clamping mechanisms, respectively, and the third is part of the flashing and upsetting mechanism.

Abstract: A welding bulge removing apparatus comprises a ring-shaped carrier adapted to be placed by means of rollers on welded pipes at the weld bulge, and being provided with a circumferential guideway and gear rim. It also comprises motor-operated carriages each having a driving gear wheel and support rollers. Mounted on the carriages are milling cutter units movable to and from the weld bulge. The gear wheel and the support rollers are brought respectively into engagement with the gear rim and the circumferential carrier.

Abstract: According to the invention, the ring transformer for resistance butt welders comprises a plurality of sections, each composed of a non-closed magnetic core, a part of the primary winding and a part of the secondary winding. Each section is so arranged with respect to the other sections that the end faces of its non-closed magnetic core are in contact with the end faces of the two adjacent sections, whereby the non-closed magnetic cores of all the sections make up a closed magnetic core of the transformer. The primary winding of each section is connected to those of all the other sections so that they all make up the primary winding of the transformer. The secondary winding of each section is connected to those of the other sections so that they all make up the secondary winding of the transformer.

Abstract: The base of the apparatus has the form of a claw clamp with two grips for gripping a rail that are kinematically linked with a clamping cylinder. The apparatus incorporates an upper cutter and side cutters, mounted so that, with the claw clamp closed, the cutting edges of the cutters form an outline embracing the cross-sectional perimeter of the rail. Each side cutter is hinged to the respective grip and mounted thereon for a displacement parallel to the axis of symmetry of the outline formed by the cutting edges of the cutters. The upper cutter is kinematically linked with the rod of the clamping cylinder via a clearance take-up mechanism which provides for lifting the upper cutter and the side cutters hinged thereto to engage the side cutters with the rail foot underside.