I recently visited a power plant in the Caribbean to perform vibration analysis services. As I discussed the agenda with my point of contact,  I asked for a walk-through of his facility. I was a bit surprised to see the amount of rotating equipment present in such a small area. But in particular, I was surprised to hear a lot of loud noise coming from several different auxiliary machines. Even though I had my PPE gear on, I still heard a very large pitching-type noise.

As I found that noise rather high and annoying, I asked my point of contact about the particulars of this motor pump assembly. The pump has been in service for quite a while and they recently replaced the bearings and couplings.

I asked what type of method they were using to align their equipment and the answer was straight edge and dial indicator, but that the coupling and pump bearings were new.
Motor pump assembly
I took the opportunity to get my VIBXPERT® II vibration analyzer out and collect data on that particular machine first. To no surprise, the data showed severe misalignment across the coupling. I reconfirmed the data using phase analysis. I noticed while doing this that the pump was hot. After viewing the data on the analyzer I asked the customer if they had thermal growth specifications for that machine. He was unaware of them having any such data for the pump. I advised him that there are systems out there that could not only perform the alignment but could also measure the amount of dynamic movement that occurs on a machine, a true cold to hot or hot to cold measurement.

The following day the customer was able to bring the machine down for a few minutes and we mounted a ROTALIGN® ULTRA IS laser alignment system and took alignment readings. Within seconds we confirmed that machines were severely misaligned, as had been indicated by the VIBXPERT. Next, we installed LiveTrend brackets and ran the machine for approximately 45 minutes, and as expected they showed a rather large positional change as they ramped up. The customer was not only able to see the misalignment using vibration technology but also found a solution to his reliability problems. The overstocking of couplings and bearings could now be reduced with the true and accurate data obtained from the laser alignment system and vibration data collector and analyzer.

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, by Alex Nino CRL