Page 181 - Rotating Machinery Pratical Solutions to Unbalance and Misalignment

Reverse Indicator Alignment

On the stationary and adjustable indicator lines,
measure the distance and direction ( ±) to the
final alignment line and enter below

▼ ▼
▲ S A ▼
▼
Change ±

▼ ▼
Times 2 Times 2
▼
▼
▼ ▼
▲ Desired final readings
▼
STIR ATIR

Figure 9-10. Final Alignment Readings for Reverse Indicator Align-
ment

ary indicator line at plus five (+5). Therefore the stationary indi-
cator reading (STIR) should be plus ten (+10). The cold alignment
line crosses the adjustable indicator line at plus two (+2). The final
adjustable indicator reading (ATIR) should be minus four (–4).
One final word about alignment. Regardless of the method
employed, when readings are taken from one machine to the
other, the readings always must have their algebraic signs
changed, so that the readings are transferred back to the original
machine.
In the reverse indicator method, the stationary machine read-
ing was not changed, since it was already a reading on the station-
ary machine. Note however that all other readings presented in
either method required transferring back to the stationary ma-
chine, since they were read across the coupling.
Also, all rim or bore readings must be divided by two, regardless
of the alignment technique employed.