摘要 |
<p>A method of seam welding metal tube from a sheet metal blank wherein the sheet metal blank is provided with central key locating slots and pre-curled edges, then centrally located on a collapsible mandrel, having a heat sink liner extending therearound to a longitudinally extending gas gallery slot, by the key locating slots and then skid rolled therearound towards a longitudinally extending gas gallery slot for seam welding the curled edges while they are clamped to the collapsible mandrel over the gas gallery slot. Pre-curling the edges avoids upstanding edges at the seam weld and the method provides consistently reliable welds for tube blanks which may be manufactured in short lengths for, for example, the manufacture of bellows.</p> |