Goulds Pumps HS - IOM - Manual (Page 16)

10
HS IOM 5/08
Angular and parallel misalignment are corrected by
means of shims under the motor mounting feet. After
each change, it is necessary to recheck the alignment of
the coupling halves. Adjustment in one direction may
disturb adjustments already made in another direction.
It should not be necessary to adjust the shims under the
pump.
The permissible amount of misalignment will vary
with the type of pump and driver. The manufacturer’s
recommendations should be obtained and followed.
When the driver is to be mounted on the subbase in the
field, it is necessary to place the subbase with the
pump on the foundation to level the pump shaft, to
check the coupling faces, the suction and discharge
flanges for horizontal or vertical position, and to make
any necessary corrective adjustments.
When the units are lined up cold, it may be necessary
to make an allowance for the vertical rise of the driver
and/or pump caused by heating.
3. Alternate Method of Alignment An approved
method for putting the coupling halves in final accurate
alignment is by the use of a dial indicator. Check
alignment by straight edge, taper gauge or feelers as
accurately as possible by procedure indicated above.
Bolt the indicator to the pump half of the coupling.
With the indicator button resting on the other half
coupling periphery, set the dial to zero, and chalk mark
the coupling half at the point where the buttons rest.
For any check (top, bottom, or sides) rotate both shafts
by the same amount; i.e., all readings on the dial must
be made with button on the chalk mark.
The dial readings will indicate whether the driver has
to be raised or lowered or moved to either side. After
each movement, check to see that coupling faces
remain parallel to one another.
With this method, accurate alignment of shaft centers
can be obtained even where faces or outside diameters
of the coupling halves are not square or concentric
with the bores, provided all measurements for angular
alignment are made between the same two points on
the faces, and all measurements for parallel alignment
are made between the same two points on the outside
diameters. Gross deviations in squareness or
concentricity, however, may cause problems due to the
coupling unbalance or abnormal coupling wear and
may need to be corrected for reasons other than
accomplishment of shaft alignment.
4. Alignment of Gear Type Couplings Gear type
couplings are aligned in the same manner as outlined
above. However, the coupling covers must be moved
back out of the way and measurements made on the
coupling hubs as shown on Fig.W9.
5. 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, seasoning, or spring of the foundation.
2. Wear of the bearings.
3. Pipe strains distorting or shifting the machine.
4. Springing of the baseplate by heat from an adjacent
steam pipe or from a steam turbine.
5. Shifting of the building structure due to variable
loading or other causes.
6. Loose nuts or bolts on the pump or driver assembly.