After plasmas tank cutting to shape, the plate requires a 30 ° bevel with a 1/16 inch land on all four edges. Then wire brushes clean 12 inches back from beveled edges, a bending machines rolls the plate into cylinders, nine feet in diameter. GMAW guns on booms weld the cylinders in flat position.
With the seam on the bottom, machines weld one pass at a current of 310 to 320 amps on the beveled side. The guns move at 10 to 14 in./ min. to weld longitudinal seams.
Then, with guns stationary, the cylinders rotate to make circumferential welds. Milling backchips the joint to solid weld metal for the final pass, laid in at 340 to 360 amps from the outside of the cylinder. Fillers: 5654 or 5254 aluminum plate and 5356 or 5554 (depending on customer specification) for 5454 plate.
X-rays inspect all tank car cylinder welds. Faced with overhaul of its large beveling plainer, at a cost of $50 000 to $80 000 the customer found that it could improve operations . Two small portable bevellers now on the line in place of the plainer have doubled the rate of plate edge beveling at the plant.
