Installation
Model 3410 Installation, Operation, and Maintenance Manual
25
Types of misalignment
Type of misalignment
Description
Angular misalignment
Shafts have an axis concentric at the intersection but not parallel.
Parallel offset misalignment
Shafts have an axis parallel but offset.
Check and correct angular misalignment before correcting parallel misalignment.
Permissible coupling misalignment
Type of misalignment
Single element coupling
Double element (spacer) coupling
Parallel misalignment
0.1 mm | 0.004 in. TIR (4 mils)
1.52 mm | 0.060 in. TIR per foot of
spacer length
Angular misalignment
0.1 mm | 0.004 in. TIR per inch of
radius.
0.51 mm | 0.002 in. TIR per inch of
radius
Types of alignment checks
Type of check
When it is used
Initial alignment (cold alignment)
check
Prior to operation when the pump and the driver are at ambient
temperature.
Final alignment (hot alignment)
check
After operation when the pump and the driver are at operating
temperature.
To make the final alignment, move and shim the motor on its base until the coupling hubs are
within the recommended tolerances measured in total runout. Take all measurements with the
pump and driver bolts tightened. Make the final alignment check after the unit has attained its
final operating temperature.
Initial alignment (cold alignment) checks
When
Why
Before you grout the baseplate
This ensures that alignment can be accomplished.
After you grout the baseplate
This ensures that no changes have occurred during the grouting
process.
After you connect the piping
This ensures that pipe strains have not altered the alignment.
Final alignment (hot alignment) checks
When
Why
After the first run
This ensures correct alignment when both the pump and the driver
are at operating temperature.
Periodically
This follows the plant operating procedures.
Cold settings for parallel vertical alignment
Introduction
This section shows the recommended preliminary (cold) settings for electric motor-driven
pumps based on different temperatures of pumped fluid. Consult driver manufacturers for
recommended cold settings for other types of drivers such as steam turbines and engines.
Recommended settings
Pumped fluid temperature
Recommended setting for driver shaft
Ambient
0.05 mm | 0.002 in. to 0.102 mm | 0.004 in., low
38°C | 100°F
0.00 mm | 0.000 in. to 0.05 mm | 0.002 in, high
93°C | 200°F
0.102 mm | 0.004 in. to 0.152 mm | 0.006 in., high
149°C | 300°F
0.203 mm | 0.008 in. to 0.254 mm | 0.010 in., high
204°C | 400°F
0.305 mm | 0.012 in. to 0.356 mm | 0.014 in., high
Align the pump using a straight edge
Before you begin, you must have a straight edge and a taper gauge or set of feeler gauges.
