Method and apparatus for producing continuous lengths of coilable tubing

Abstract From the Canadian patent

A system for making a long length of seam-welded tubing from shorter lengths of flat metal strip which are spliced end-to-end and formed into tubular form and seamwelded. Adjoining ends of two successive lengths of the strip are trimmed at supplementary angles one of which is, an acute angle. The trimmed ends are abutted and welded preferably with weldment extending beyond each such end. All surfaces of the weld are finished to match the dimensions of the strip. The tubing, along with the welded joints, is heat treated as the tubing is formed to produce a product substantially free of internal surface roughness along the splice welds.