Goulds Pumps 3500XD - IOM - Manual (Page 19)

Final Alignment (Hot Alignment)
·
After First Run - To obtain correct alignment when
both pump and driver are at operating temperature.
Thereafter, alignment should be checked periodically
in accordance with plant operating procedures.
ALIGNMENT CRITERIA
Good alignment is achieved when the dial indicator
readings as specified in the alignment procedure are .05
mm (.002 in.) Total Indicated Reading (T.I.R.) or less
when the pump and driver are at operating temperature
(Final Alignment).
During the installation phase, however, it is necessary to set
the parallel alignment in the vertical direction to a different
criteria due to the differences in expansion rates of the
pump and driver. Table 1 shows recommended preliminary
(cold) settings for electrical motor driven pumps based on
different pumpage temperatures. Driver manufacturers
should be consulted for recommended cold settings for
other types of drivers (steam turbines, engines, etc.)
Table 1
Cold Setting of Parallel
Vertical Alignment
Pumpage
Temperature
Set Driver Shaft
10° C (50° F) .05 mm (.002 in.) LOW
65° C (150° F) .03 mm (.001 in.) High
120° C (250° F) .12 mm (.005 in.) High
SET UP
1. Mount two dial indicators on one of the coupling
halves (X) so they contact the other coupling half (Y)
(Fig. 9).
2. Check setting of indicators by rotating coupling half X
to ensure indicators stay in contact with coupling half
Y but do not bottom out. Adjust indicators
accordingly.
MEASUREMENT
1. To ensure accuracy of indicator readings, always rotate
both coupling halves together so indicators contact the
same point on coupling half Y. This will eliminate any
measurement problems due to runout on coupling half
Y.
2. Take indicator measurements with driver feet
hold-down bolts tightened. Loosen hold down bolts
prior to making alignment corrections.
3. Take care not to damage indicators when moving
driver during alignment corrections.
ANGULAR ALIGNMENT
A unit is in angular alignment when indicator A (Angular
indicator) does not vary by more than
.05 mm (.002 in.) as measured at four points 90° apart.
Vertical Correction (Top-to-Bottom)
1. Zero indicator A at top dead center (12 o’clock) of
coupling half Y.
2. Rotate indicators to bottom dead center (6 o’clock).
Observe needle and record reading.
3. Negative Reading - The coupling halves are further
apart at the bottom than at the top. Correct by either
raising the driver feet at the shaft end (add shims) or
lowering feet at the other end (remove shims)
(Fig. 10).
Positive Reading - The coupling halves are closer at the
bottom than at the top. Correct by either lowering the
driver feet at the shaft end (remove shims) or raising the
driver feet at the other end (add shims).
3500XD IOM 8/07
15
Fig. 9
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