Alignment bracket assembly integrity check and sag determination

Abstract

Methods for verifying the mechanical integrity of an alignment bracket, particularly a multi-configurable alignment bracket, used for aligning co-rotatable in-line machine shafts, and for determining the amount of alignment bracket 'sag' to be accounted for when subsequently employing readings taken with the alignment bracket. The invention employs a previously-established relationship between sag and deflection of the alignment bracket under the influence of a known force to determine sag and to verify mechanical integrity of the alignment bracket in situ, avoiding the need for the usual prealignment sag determination on a separate straight pipe or mandrel. In the practice of the method, the alignment bracket is set up in a position for use, on the actual shafts being aligned. The extension bar of the alignment bracket is positioned above the centerlines of the shafts, and a known force is applied by hanging a known weight at a predetermined point on the alignment bracket. This force results in a deflection of the extension bar, which is measured. From the measured deflection, a sag value is determined based on a previously-determined relationship. To verify integrity of the alignment bracket, measured deflection is preliminarily compared to a range of acceptable deflection values for the particular alignment bracket dimensional configuration.