Apparatus for Flash Butt-Welding Pipes

1,167,167. Welding by pressure. INSTITUT ELEKTROSVARKI IMENI E. O. PATONA. 8 Nov., 1966, No. 50008/66. Heading B3R. Apparatus for flash butt welding pipes comprises a lifting mechanism supporting a flashbutt welding machine which defines a substantially circular opening capable of being disposed coaxially with a pair of vertical pipes to be welded, the machine being capable of being displaced by the lifting mechanism longitudinally with respect to the pipes and having two interconnected bodies each including a self-centring pipe clamp. Two uprights 2 mounted on the platform 1 of a drilling installation carry a platform 3 which in turn carries a hydraulic power system 5 and a hydraulic telescopic lifting device 6, the latter supporting the welding machine 7. A working platform 9 is provided for the operator. The welding machine 7 comprises an upper clamping device 10 connected by rods 12 from hydraulic cylinders 13 to a lower clamping device 11, the latter carrying an annular welding transformer 15 whose secondary is connected to contact jaws 18, 19 of the devices 11 and 10 respectively. Each clamping device comprises a two-part body 21, 22 in which are arranged radially movable clamping shoes 23 having ends with bevels of different angles engaged by rollers 25 on a ring 24 rotatable by hydraulic cylinder devices to move the shoes radially towards and away from a central aperture through the machine. In operation the welding machine is lowered by the device 6 to its dotted line position in Fig. 1, a first pipe is lowered into the drill hole until its upper end is in the welding zone and it is secured in the platform 1. The machine 7 is then raised by device 6, a further pipe is fed to the machine and the pipes are clamped in devices 10, 11. Current is supplied and by means of the cylinders 13 the pipes are brought together and upset in a flash butt welding operation.