Manual Chapter 5

8-4 Application Information
Pre-job Preparation and Setup
Before starting any alignment job, the history of alignments performed on
this machine(s) should be reviewed. Were any special problems found
during the previous alignment; if so, what were they (soft foot, piping strain,
coupling problems, etc.)? How well was the machine aligned and who per-
formed the alignment? Answering these questions along with having a pre-
defined job setup reduces the pre-job preparation time and decreases the
total time to do the job.
Now that the past is known, before proceeding with alignment measure-
ments, ensure that your machine(s) are mounted perfectly parallel with the
base or foundation. If they are not parallel, additional stress may be placed
on the machine when the anchor bolts are tightened. Uneven height of the
base surface, dirt or corrosion under the feet, or other irregularities can all
cause the machine to be supported unevenly – a condition known as “soft
foot”. In addition to preventing proper machine alignment, extreme soft
foot conditions can actually cause damage to the machine (warped or
cracked feet, etc.).
Two major reasons for correcting soft foot are (1) to avoid “chasing your
tail” during the alignment and (2) to remove the stress and enable the
machine(s) to operate at their best. Therefore, all machines should be
checked for soft foot, not just the machine being moved.
Additional pre-alignment considerations include:
• Proper foundation
• Grouting (suitable material with no voids or cracks)
• Baseplate (must be clean, rigid, and properly designed)
• Coupling (properly selected and installed)
• Machinery element supports (no cracks and tight)
• Minimize pipe strain
Chapter 8 Page 4 Friday, January 26, 2001 10:34 AM