Page 323 - Intro Predictive Maintenance

314 An Introduction to Predictive Maintenance

Figure 14–25 Load from narrow strip concentrated in center.

Figure 14–26 Roll loading.

This extremely important factor can be used to evaluate many of the failure modes of
continuous process lines. For example, the vibration profile resulting from the trans-
mission of strip tension to the roll and its bearings can be used to determine proper
roll alignment, strip tracking, and proper strip tension.

Alignment
Process rolls must be properly aligned. The perception that they can be misaligned
without causing poor quality, reduced capacity, and premature roll failure is incorrect.
In the case of single rolls (e.g., bridle and furnace rolls), they must be perpendicular
to the pass line and have the same elevation on both the operator and drive sides. Roll
pairs such as scrubber/backup rolls must be parallel to each other.