HPXM USER INSTRUCTIONS ENGLISH 14983571 - 03/11
Page 19 of 48
and loosen off the holding down bolt while noting any
deflection reading on the Dial Test Indicator - a
maximum of 0.05 mm (0.002 in.) is considered
acceptable but any more will have to be corrected by
adding shims, for example, if the Dial Test Indicator
shows the foot lifting 0.15 mm (0.006 in.) then this is
the thickness of shim to be placed under that foot.
Tighten down and repeat the same procedure on all
other feet until all are within tolerance
If the driver is an electric motor with sleeve
bearings then the magnetic centre at which the rotor
will run must be set. This is usually done by lining up
a groove in the shaft to a pointer fixed to the motor
body (refer to Motor Manufacture’s instructions).
4.5.2.3 Alignment using a graph (Reverse
Alignment)
Ensure pump and driver are isolated
electrically and the half couplings are disconnected.
The alignment MUST be checked.
Although the pump will have been aligned at the
factory it is most likely that this alignment will have
been disturbed during transportation or handling. If
necessary, align the motor to the pump, not the pump
to the motor.
The alignment is achieved by adding or removing
shims under the motor feet and also moving the
motor horizontally as required. In some cases where
the alignment cannot be achieved it will be necessary
to move the pump before recommencing the above
procedure.
For couplings with narrow flanges use a dial indicator
as shown below to check both parallel and angular
alignment.
Parallel
Angular
Figure 4.11
Maximum permissible misalignment at working
temperature:
Parallel 0.05 mm (0.002 in.) TIR
Angular 0.025 mm (0.001 in.) TIR
Pumps with thick flanged non-spacer couplings can
be aligned by using a straight-edge across the
outside diameters of the coupling hubs and
measuring the gap between the machined faces
using feeler gauges, measuring wedge or calipers.
When the electric motor has sleeve bearings it is
necessary to ensure that the motor is aligned to run
on its magnetic centreline.
Refer to the motor manual for details.
A button (screwed into one of the shaft ends) is
normally fitted between the motor and pump shaft
ends to fix the axial position.
If the motor does not run in its
magnetic centre the resultant additional axial force
may overload the pump thrust bearing.
Complete piping as below and see sections 4.7,
“Final shaft alignment check”
up to and including
section 5,
“Commissioning, start-up, operation and
shutdown”
before connecting driver and checking
actual rotation.
4.5.3 Shims
The shims between the equipment feet and mounting
surface should be clean and dry. This is especially
critical for pumps in service for sometime and need to
be realigned. Water, dirt and rust may change the
height of the shim pack over a period of time. Shims
should be made large enough to support the weight
of the equipment on its mounting foot. Do not use
many thin shims as this may result in a spongy
mounting.
Figure 4.12
Recommended shim design
Move the equipment vertically by adding or removing
the calculated thickness of shims. Torque holding
down bolts to required values.
4.5.4 Hot alignment – Pump and driver dowels
Pump hold down bolts are to be torqued down and
dowel pins are to be located in pump feet as Figure
4.10. (This is only applicable if Hot Alignment is
required)
