Full definition
The process of positioning two coupled rotating shafts so they are collinear (or properly offset for gear couplings) within tight tolerances using laser alignment instruments. Target tolerances per machinery class: general industrial <0.05 mm parallel offset and <0.05 mm/100 mm angular misalignment; precision machinery <0.02 mm offset. Misalignment is the second leading cause of premature bearing and seal failure (after contamination), responsible for up to 50% of rotating machinery breakdowns. Laser alignment achieves 10x better accuracy than dial indicator methods and is 4x faster. Procedure: soft-foot correction first, then vertical angular, vertical offset, horizontal angular, horizontal offset. Modern tools compensate for thermal growth (hot alignment targets). Per API 686 and ISO 10816 for alignment tolerances. Tools: SKF TKSA 71/80, Fixturlaser NXA Pro, Pruftechnik/Fluke Rotalign Touch. Studies show that proper alignment reduces bearing replacement by 50%, seal replacement by 65%, and energy consumption by 2-5%.