Purpose

The purpose of this standard is to guarantee reliability of mechanical equipment when first placed into service and after major repair. It specifies the alignment condition of components to reduce vibration and minimize wear.

Reducing dynamics forces at mechanical joints is the objective of alignment, but vibration shall not be used as a judgment criterion for acceptable alignment. Other defects can cause vibration, including the foundation and other building parts. The craftsperson who performs the alignment uses static measurements when the machine is stopped, and the same static methods shall be used to judge acceptability.

This standard does not limit the contractor with required instruments or methods. Rather, it defines the final orientation. It does, however, require that some preliminary factors be considered and that some additional measurements be taken to ensure that the mechanical system is not strained or distorted. These are considered part of the general process of setting up machinery, of which precision alignment is a part. The purpose of this standard is to make sure that these general factors are not overlooked.

The aligner will be required to document the alignment task. As a minimum, the before and after orientation shall be reported, along with any changes made. The vibration after start-up is not directly relevant to acceptable alignment. If the final orientation is within acceptable limits as determined with static measurements, and if the mechanical system is demonstrated to be not distorted or strained, then the alignment is acceptable.

The purpose of this...