Page 168 - Know and Understand Centrifugal Pumps

Pump and Motor Alignment
n

SOFT FOOT 1
n
J7 SHORT FOOT

c 1

DISTORTED I BENT FOOT
TOO MANY SHIMS

DISTORTED I BENT FOOT DIRT BETWEEN FOOT AND BASE

Fiaure 10-13

To correct soft foot, place shims under the foot in the thickness
corresponding to the movement of the dial indicator.
If the foot inclines from either the outer or inner border, it will
always rise upon loosening the base bolt, and correct alignment
will be almost impossible. It will be necessary to re-machine all
four feet to achieve parallelism between them.
10. Check for indicator bar shaft deflection.
This deflection is due to the weight of the indicator dial.

Mount the dial indicators on the equipment in the same manner
and distance required to perform the alignment procedure.
Start straight up at the top of the shaft and rotate 180" down to
the bottom.
Note the indicator readings.
This deflection can be corrected easily during the alignment. For
example, with the indicators in the upper position on the shaft,
instead of starting at 0.000 inches, mark the positive value of the
deflection of the bar determined in the previous step, and then
rotate the shaft 180" to the bottom. Now the indicators will
read 0.000 inches.

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