Page 278 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

260 Major Process Equipment Maintenance and Repair

Table 6-1
Recommended Maximum Allowable Runout
During Coupling Alignment, In. TIR
Maximum Allowable Run-Out,
Inches, TIR
Shaft Surface
Velocity, feet Outside Diameter
per mlnute of Coupling Coupling Face
5000 and up .002 .OOO4 per in. of radius
3000 to 5000 .004 .OW5 per in. of radius
1500 to 3000 .006 .0006 per in. of radius
500 to 1500 .008 .0008 per in. of radius
500 and down .010 .0010 per in. of radius

3. Record the approximate “R” dimension and the outside diameter
and face readings at 90” intervals starting at 12 o’clock. NOTE:
Readings and correction requirements should be noted before unit
temperatures reach ambient conditions.
4. Correct alignment as needed before unit cools.
5. Redowel unit to foundation if necessary before unit cools.
6. Work machinery until operating temperatures are stabilized, then:

a. Quickly install clamps and indicators at both couplings.
b. Hand rotate shafts in the direction they will turn.
c. Record the approximate “R” dimension and the outside diameter
and face readings at 12 o’clock, three o’clock, six o’clock, and
nine o’clock.

NOTE: When aligning units with tilting pad journal bearings, it is espe-
cially important that the shafts be rotated in one direction only during
alignment.

Checklist Before Startup

Before startup, certain checks should be made to protect personnel and
equipment. If a checklist written by the manufacturer is not available, the
following list can be used as a guideline to develop a suitable procedure:
1. Check the lubrication system for the correct type and quantity of
oil. If a splash system is used, be sure the gears or slingers dip in
oil.