During a recent Fixturlaser GO Pro Training class, at a mid-west university, we performed a shaft alignment on a large Flowserve HVAC pump with a 500 HP electric motor. This motor was large enough that multiple people could work on both sides without really seeing each other. Well, that proved to be an issue with this alignment.
The training class was large and everyone was eager to participate in the “hands on” portion of the class on their house equipment. This was a great opportunity as this customer keeps their pump house in extremely nice condition, with all of the pumps, pipes and other equipment clean enough to eat off!
Things were going great with the alignment, using the Verti-Zontal Compound MoveTM process, until the class began tightening the motor hold down bolts. As the bolts were being torqued down, we were seeing up to 5 mils of horizontal movement at the motor feet which was throwing the horizontal coupling values out of tolerance dramatically.
After observing my class making several attempts to re-adjust and re-measure, it became clear what was happening. This motor was large enough that several people were working on each side and there was no coordination or “pattern” to the bolt tightening sequence. While torqueing the motor bolts, various people would throw their wrenches on and start pulling. They were not following any pattern and had no communication from one side to the other.
Adding to this, there were multiple people attempting to keep the motor shaft from moving with their hands while others were operating the “jack bolts” during the live, horizontal correction. A case of too many chefs in the kitchen with no communication. This was allowing some movement of the motor shaft causing our coupling values to drift. During the live adjustment phase, it is important that the shaft/sensor movement be eliminated with a steady rest. If the sensors are moving so are the numbers!
Once we established a procedure where one person was holding the motor shaft while watching the inclinometers values on the Go-Pro screen, and one person was selected on each side to torque the motor in the correct sequence, our alignment “dialed” right into tolerance.
Some direction and a little coordination allowed this alignment to be finished quickly, accurately and showed the class a very important fundamental while performing a large pump shaft alignment. Communicate and work as a team!
1 Comment
great blog…along these lines, I always suggest one person to do all of the math and shim corrections. It is very interesting to see how simple math becomes very confusing when 4 people are calculating and trying to do shim “trade ups”.