Goulds Pumps 3408 - IOM - Manual (Page 16)

16
3408 IOM 03/99
taken with the pump and driver bolts tightened. Final
alignment check should be made after the unit has
attained its final operating temperature.
Method 1 - Using straight edge and taper gauges or
feelers (Fig. 10):
Proceed with this method only if satisfied that face
and outside diameters of the coupling halves are
square and concentric with the coupling bores. If this
condition does not exist or elastomeric couplings do
not make this method convenient, use Method 2.
Check for angular alignment by inserting the taper or
feeler gauges between the coupling faces at 90°
intervals. The unit is in angular alignment when these
four (4) measurements are the same, or within
recommended tolerances.
Check for parallel alignment by placing a straight
edge across both coupling rims on all four sides. The
unit is in parallel alignment when the straight edge
rests evenly across both coupling rims in all four (4)
positions.
Method 2 - Dial Indicators (Fig. 11):
A dial indicator can be used to attain more accurate
alignment.
Fasten the indicator stand or magnetic base to the
pump half of the coupling and adjust the assembly
until the indicator button is resting on the other half
coupling periphery.
Set the dial to zero and chalk mark the coupling half
where the button rests. Also place a separator
between the coupling halves so bearing slack does
not affect the readings. (Chalk and separators are not
necessary on the elastomeric couplings that have not
been disconnected.) Rotate both shafts by the same
amount; i.e., all readings must be made with the
button on the chalk mark.
The dial readings will indicate whether the driver has
to be raised, lowered or moved to either side.
Accurate alignment of shaft centers can be obtained
with this method even where faces or outside
diameters of the coupling are not square or concentric
with the bores. After each adjustment, recheck both
parallel and angular alignments.
NOTE: Gross deviations in squareness or
concentricity may cause rotation unbalance
problems and if so must be corrected.
Permissible Coupling Misalignment:
Parallel: Single element coupling:
.004" TIR (4 mils)
Double element (spacer) coupling:
.060" TIR per foot of spacer length
Angular: Single element coupling:
.004" TIP per inch of radius
Double element (spacer) coupling:
.002" TIR per inch of radius
Fig. 10