Improvements in or relating to the production of welded tube.

摘要

The invention provides a method of welding a bead along the edges of metallic plate or strip formed into tube shape by means of a welder head movably carried by a beam (2) disposed longitudinally to the tube (1), comprising the steps of monitoring the deviation of the seam (3) at a first point along the tube (1) from a plane passing through or parallel to the tube axis, monitoring the deviation of the weld line from the same plane at a second position along the tube (1), computing from the data so acquired a deviation factor for the weld line along the tube, and applying a weld bead along the weld seam whilst monitoring the position of the welding head about the tube and at the same time producing a signal indicative of variations during welding between the transverse position of the welding head and the previously calculated deviation factor for that position along the tube.