A customer in Florida needed to do an alignment between a gas turbine and a generator. Their main issue was that the gas turbine shaft could not be rotated by hand and engineering was reluctant at that time to turn on the lift oil pumps. This customer owns and uses the ROTALIGN® ULTRA iS. We suggested using the Multipoint measurement mode in the ROTALIGN ULTRA iS in conjunction with one ALI 2.230 Magnetic Sliding Bracket for the turbine shaft and one ALI 2.112set Compact Magnetic Bracket. With the shafts uncoupled,  the generator shaft could be rotated to any position,  and the sensor could be positioned at any rotational position on the turbine shaft with the magnetic sliding bracket. A very big advantage of using the ROTALIGN ULTRA iS in the Multipoint mode is that thanks to the quality factor value obtained from the readings a very clear picture emerges of the quality of the data obtained while taking the readings. Any rogue measurements caused by surface imperfections in the turbine coupling can be eliminated without compromising otherwise good data. The ROTALIGN ULTRA’s Technical Note # 12 – for Non-Rotating Shafts was provided to the customer to better guide the process.
Magnetic bracketSliding bracket
Accurate readings were obtained quickly and efficiently, resulting in many man-hours saved on this critical alignment job.

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by Alan Luedeking CRL CMRP