Apparatus for overheating edges of skelp for the production of compression welded pipe

Claim 1

Induction heating apparatus for the overheating of the edges of preheated skelp which has been formed into a circular open shape, said apparatus comprising an induction heating coil assembly having a pair of electrically series-connected loops, each loop having a main conductor and a return conductor co-planar therewith, said main conductors being positioned within magnetic flux guides disposed over the outermost and uppermost sides of each of the said main conductors, which main conductors are each adapted to be positioned in spaced proximity to a different linear edge of the preheated open skelp to concentrate the currents along the said edges of the skelp and to provide uniform equal localized heating to welding temperature of both said preheated edges to weld the same, the return conductors positioned externally to the flux guides providing a distribution of return currents over a relatively greater area.