scope:

This American National Standard gives guidelines for applying shaft vibration evaluation criteria, under normal operating conditions, measured at or close to the bearings of some types of non-reciprocating shipboard machinery. These guidelines are presented in terms of both steady vibration amplitudes and changes in amplitudes which may occur in these steady values. 

Purpose

The purpose of this standard is to provide specific guidance for assessing the severity of vibrations measured on rotating shafts of large shipboard machines with fluid film bearings, whenever such measurements are required, so as to insure smooth operation from the standpoint of mechanical suitability. 

Applications

This part applies to large shipboard machines with oil film bearings, such as main propulsion turbines and gears, and turbo-generators. It does not apply to machines with rolling element bearings. Machinery specifications should state when the measurement of relative shaft vibration is required. These guidelines apply to acceptance tests for new machinery, and in-situ testing for monitoring purposes.