NOTICE:
Care must be taken to have the straight edge parallel to the axis of the shafts
Complete Alignment
A unit is in complete alignment when both indicators "A" (angular) and "P" (parallel) do not vary by more
than 0.076mm | 0.003" as measured at four points 90° apart.
Vertical Correction (Top-to-Bottom)
1.
Zero indicators “A” and “P” at top dead center (12 o'clock) of coupling half (Y).
2.
Rotate indicator to bottom dead center (6 o'clock). Observe the needles and record the readings.
3.
Make corrections as outlined previously.
Horizontal Correction (Side-to-Side)
1.
Zero indicators "A" and "P" on the left side of coupling half (Y), 90° from top dead center (9
o'clock).
2.
Rotate indicators through, top dead center to the right side, 180° from the start (3 o'clock), Ob-
serve the needle, measure and record the reading.
3.
Make corrections as outlined previously.
4.
Recheck both vertical and horizontal readings to ensure adjustment of one did not disturb the
other. Correct as necessary.
Factors that may disturb alignment
The unit should be checked periodically for alignment. If the unit does not stay in line after being properly
installed, the following are possible causes:
1.
Settling or spring of the foundation.
2.
Wear of bearings.
3.
Pipe strains distorting or shifting the machine.
4.
Shifting of the sub-base due to heat created from an adjacent heat source.
5.
Shifting of the building structure due to variable loading or other causes.
6.
Loose nuts or bolts on the pump or driver assembly.
NOTICE:
With experience, the installer will understand the interaction between angular and parallel and
will make corrections appropriately.
4.5 Impeller Alignment
Improper impeller adjustment could cause contact between the rotating and stationary parts, resulting
in a spark and heat generation.
The impeller clearance setting procedure must be followed. Improperly setting the clearance or not fol-
lowing any of the proper procedures can result in sparks, unexpected heat generation and equipment
damage.
The AF impeller has been aligned at the factory but should be checked prior to pump operation. The im-
peller requires several thousandths of an inch of clearance to prevent rubbing due to the action of hy-
draulic forces when the pump is operating. Many corrosion-resistant alloys will gall and build up if rub-
bing occurs, therefore, pumps using these alloys need to be free from any rubbing.
4.5 Impeller Alignment
32
Model AF (42"/1200mm/54"/60"/66") LM/LMR Bearings Installation, Operation, and Maintenance Manual
