Categories: Shaft Alignment

Align a Cooling Tower in Under an Hour

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By on February 7, 2012

Aligning cooling towers with spacer shafts can sometimes present a challenge.  We recently provided alignment training and assistance to the HVAC Group at the Federal Reserve Bank in Richmond, VA.

This was a Marley cooling tower, with a 60 HP motor, connected to the gearbox by a 48″ spacer shaft.

That’s me, the trainer, inside the fan.  The mechanics are using their Fixturlaser XA, and telling me how to shim up their gearbox.  How often do you get that from a trainer?

The motor had recently been changed to an inverter-duty motor, in preparation for installing variable speed drives on this tower.

The initial measurements showed that the motor was sitting about 1/8″ too high.  There were no shims under the motor, so it could not be easily lowered.

Before Alignment







Using Live Mode, and employing the Verti-Zontal process, we shimmed the gearbox up vertically to correct a base-bound problem, twisted it horizontally a bit to correct a bolt-bound problem on the motor, and completed vertical shimming of the motor to align it to the gearbox.

After Alignment







Total time to align – 22 minutes!

Align a cooling tower – in under an hour?  That’s Verti-Zontal power!

About the Author

Stan Riddle joined VibrAlign in 2008. He has over 35 years experience in aligning industrial machinery. Stan received his AAS Degree in Machinist Technology from Surry Community College in Dobson, NC, and also holds a diploma in Industrial Systems Technology from Forsyth Technical Community College in Winston-Salem, NC, where he was also an instructor in the program.

Stan began his maintenance career working as a machinist and millwright for companies such as Weyerhaeuser, R.J. Reynolds, and Tyco Electronics. He also has over 25 years experience in Predictive Technologies, such as vibration analysis, thermography, oil analysis, and ultrasonic inspection. He is a certified Level III Vibration Analyst with the Vibration Institute, and is a Past Chairman and Board Member of the Piedmont Chapter.

Stan and his wife live in Yadkinville, NC.

2 responses to “Align a Cooling Tower in Under an Hour”

  1. Rodney says:

    What is the alignment procedure for Marley Gear reducer, model 2200 and fan blades correct positioning

  2. Stan Riddle says:

    Rodney, thanks for dropping in! I can’t speak for Marley, but I found several references online for their alignment specs. Does your tower use a spacer shaft? If so, their tolerance is pretty forgiving. Our tolerances are based on rpm. With a 1785 input speed from the motor, we would align to 4 mils offset, and .7 mils per inch angularity, regardless of whether it uses a spacer shaft or not. This is easy to achieve with one of our laser tools.

    As to correct fan blade positioning, do you mean blade pitch, or clearance around the plenum, or fan shroud? Your local Marley rep could also answer that better than I could. Normally, pitch is set with inclinometers and an amp meter, to get maximum air movement without tripping the motor. Tip clearance is usually just an even amount for each blade.

    I hope this helps a little. If VibrAlign can help out with any alignment-specific questions, or for the number of your local VibrAlign rep., please let me know. Thanks again!