Permitted indicator values for alignment checks, Alignment measurement guidelines, Attach the dial indicators for alignment – Goulds Pumps 3171 - IOM User Manual

Page 26

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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.

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.
If changes have occurred, you must alter the piping to remove pipe

strains on the pump flanges.

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.

Permitted indicator values for alignment checks

NOTICE: The specified permitted reading values are valid only at operating temperature. For cold
settings, other values are permitted. You must use the correct tolerances. Failure to do so can result in
misalignment and reduced pump reliability.

When dial indicators are used to check the final alignment, the pump and drive unit are correctly aligned
when these conditions are true:

• The total indicator runout is a maximum of 0.002 in. (0.05 mm) at operating temperature.
• The tolerance of the indicator is 0.0005 in./in. (0.0127 mm/mm) of indicator separation at operating

temperature.

Alignment measurement guidelines

Guideline

Explanation

Rotate the pump coupling half and the driver coupling half

together so that the indicator rods have contact with the same

points on the driver coupling half.

This prevents incorrect measurement.

Move or shim only the driver in order to make adjustments.

This prevents strain on the piping

installations.

Make sure that the hold-down bolts for the driver feet are tight

when you take indicator measurements.

This keeps the driver stationary since

movement causes incorrect measurement.

Make sure that the hold-down bolts for the driver feet are loose

before you make alignment corrections.

This makes it possible to move the driver

when you make alignment corrections.

Check the alignment again after any mechanical adjustments.

This corrects any misalignments that an

adjustment may have caused.

Attach the dial indicators for alignment

You must have two dial indicators in order to complete this procedure.
1. Attach two dial indicators on the pump coupling half (X):

a) Attach one indicator (P) so that the indicator rod comes into contact with the perimeter of the

driver coupling half (Y).

Installation (Continued)

24

Model 3171 Installation, Operation, and Maintenance Manual

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