Patent ID: 7086576

Claim:
A method for finely adjusting, at a tack point, the width of a gap between a bottom edge of a steel side wall of an elevated cylindrical tank and a top edge of a steel strip being fed from a coil being transported by a machine moving circularly within the tank, said edges forming a joint line, the strip already having been welded along part of its length to the tank wall along the joint line behind the tack point, comprising: monitoring the plumbness, elevation and levelness of the tank wall; responsive to such monitoring, manipulating and positioning the tank wall so that it is plumb and in plane at a pre-determined elevation at the tack point; supplying, manipulating and positioning the strip so that it aligns with and assumes the curvature of the tank wall at the tack point, with the strip and wall edges being separated to provide the gap at the tack point; monitoring the width of the gap; and, responsive to such gap width monitoring, radially moving the bottom of the strip as required to thereby adjust the plumbness of the strip and effect an adjustment of the gap width at the tack point to bring it to a pre-determined optimum width for welding.