Begin by tack welding the pipe, starting on the bottom, every 6 inches once it is aligned. The welders should begin at the bottom of the pipe, working upwards to the top. Porta Power machines, wedges, modified C-clamps and other tools may be required to manipulate the steel for alignment. Also, ears or tabs may be welded on the top of one piece so it can be hung on the next piece while it is being aligned.