Initial Alignment; Straightedge Method Of Alignment; Angular Alignment; Parallel Alignment - Xylem AC Fire Pump 8100 Series Installation, Operation And Maintenance Manual

7.5

Initial Alignment

WARNING
Disconnect and lock out power before
performing alignment. Failure to follow these
instructions could result in serious personal
injury.
NOTICE
The alignment procedures that follow are for
motor driven pump units. Alignment procedures
for Engine-driven pump units are available in
the Engine manufacturer's Installation Manual.
WARNING
Replace coupler guard after performing
alignment. Failure to follow these instructions
could result in serious personal injury.
CAUTION
Misalignment causes excessive wear, vibration,
and bearing loads that result in premature
bearing failure and ultimate seizing of the pump.
NOTICE
Alignment should be made before connecting
the pipes; if not, it may not be possible to move
the pump, and it will be difficult to move the
driver.
NOTICE
Read Coupling Manufacturer instructions
supplied with the pump unit before attempting to
perform alignment.
When a complete pump unit comes pre-assembled from
the factory, the coupling has been accurately aligned by
means of shims inserted under the pump and driver.
The pump/driver could have become misaligned during
transport and installation. Misalignment can be angular,
parallel, or a combination of these, and in the horizontal and
vertical planes.
Proper alignment is essential for correct pump operation.
This should be performed after base plate has been properly
set and grout has dried thoroughly according to instructions.
Alignment should be made by moving and shimming the
driver only until the coupling hubs are within the
recommended tolerances, and should be made at operating
temperatures under normal conditions.
All measurements should be taken with the pump and driver
foot bolts tightened.
There are two types of misalignment encountered with
flexible couplings: angular misalignment, in which the shafts
are not parallel, and parallel misalignment, where the shafts
are parallel but not on the same axis.
There are three methods commonly used to determine
misalignment:
1. Straight edge and calipers.
2. Dial indicator
3. Laser Alignment Equipment (see manufacturer's
instructions for use).
AC6102 Rev 05
7.5.1

Straightedge method of alignment

The most simple alignment check is with a straight edge and
calipers. This method is the least accurate, but will serve if a
dial indicator or laser is not available.

7.5.1.1 Angular Alignment

With coupling hubs stationary, use calipers to measure the
gap between the coupling hubs at 90° intervals. Adjust and/or
shim equipment until the gap difference at all points around
the hubs is within the coupling manufacturer's guidelines,
(see Fig. 8).
Fig. 8 Angular Alignment

7.5.1.2 Parallel Alignment

With coupling hubs stationary, lay straight edge flat against
the rim of the coupling hub at 90° intervals to determine
vertical and horizontal alignment offsets. Adjust and/or shim
equipment until the straight edge lies flat against both hub
rims, vertical and horizontal. Check the coupling
manufacturer's guidelines for the permissible gap, (see Fig.
9).
Fig. 9 Parallel Alignment
7.5.2

Dial indicator method of alignment

The dial indicator should be used when greater alignment
accuracy is required. Check the coupling manufacturer's
guidelines for the acceptable alignment tolerances.
Fig. 10 Dial Indicator
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