Your foremost concern should always be safety. Never allow loose clothing or long hair anywhere near moving machinery, and make certain all equipment is
LOCKED OUT AND TAGGED OUT
TIR... Total indicator reading.
HOLE ATTACHMENT... Commonly referred to as a wiggler.
CONTACT POINT... Commonly referred to as the button.
BRACKET SAG... The distance a bracket will sag when turned from top to bottom on a coupling.
OD... Outside diameter of a coupling (rim).
FACE... The face of a coupling is the area where the two coupling halves face one another, or the area flush with the end of the shaft.
SHIM CHANGE... The amount of shims added to or taken from underneath a unit to correct the misalignment.
RADIAL ALIGNMENT... The same as the OD or parallel adjustment.
ANGULAR ALIGNMENT... Alignment of the face of a coupling.
VERTICAL DISPLACEMENT... When the OD of one coupling is higher than the other.
HORIZONTAL DISPLACEMENT... When the OD of one coupling is offset sideways from the other.
STRESS RELIEVING... The process of heating an object, such as piping, to relieve the stress that is causing misalignment.
M.G. SETS... Motors and generators in a series.
D.C. UNITS... Direct current units.
WAGON WHEEL ANALOGY... An alignment procedure using a formula for figuring the correct amount of shim change with one set of readings with the indicator. The formula is:
Pad R = Indicator reading x R/A Pad C == Indicator reading x C/A
Remember: A is the coupling diameter.
B is the horizontal distance measured in a perpendicular direction from the coupling face to the first shim pad.
C is the horizontal distance measured in a perpendicular direction from the coupling face to the outboard shim pad.