Bolt Torque and Overhung Pump Centerlines

Recently I conducted training at a location that had quite a large population of centrifugal pumps, the majority of which were overhung pumps. As you can see from the diagram below, the overhung pump casing bolts to the volute by a ring of bolts in a circular flange.     Issues with Bolt Bound and…

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Understanding Spacer Shaft Alignment

The majority of precision shaft alignments are relatively close coupled where there are only a couple of inches between the shaft ends of the driver and driven elements. Close coupled alignment quality is traditionally displayed as angle (driver to driven) and offset (at the center of the coupling). The question is what do you do…

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Base Bound Machinery Corrections

Most aligners are familiar with a bolt bound situation, which occurs when the motor cannot be moved enough to achieve proper horizontal alignment.  A base bound condition occurs when a motor cannot be lowered sufficiently to achieve proper vertical alignment.  Here is an example.  During a customer’s recent pump replacement, the motor was left in…

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Sensor Mounting

Every tool in your toolbox has a specific function and certain parameters of use to achieve a desired outcome. When you pull out a claw hammer, your intent is to drive or pull a nail. Pull out a ball peen hammer, it is still a hammer, however the use and outcome is different. You may…

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Fudging Your Shims? Go The Same Direction.

When performing a precision laser shaft alignment, it is best to add or remove shims exactly as the display unit indicates.  There are circumstances when this may not be possible due to your assortment of shims, or when you want to “fudge” your shims slightly to keep the total number of shims low. (Clink for…

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Coupling Tolerances vs. Shaft Alignment Tolerances, What’s The Difference?

Plenty! This question still comes up fairly often in our training classes. If you look any of the coupling manufactures installation instructions there is a chart for the maximum allowable misalignment based on the coupling size. These tolerances are for the coupling, what about the machines the coupling connects? Shaft alignment tolerances are more about…

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VIDEO: Concepts of Shaft Alignment – Offset & Angularity

VibrAlign, Inc. has released a new video entitled “Concepts of Shaft Alignment:  Offset and Angularity”.  The video describes and depicts how shaft alignment is quantified in the measures of offset and angularity. The video series was based on ideas for visualizing alignment created by David Zdrojewski, CEO of VibrAlign.  According to Zdrojewski, “Our research shows…

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