This part of ISO 7919 gives guidelines for applying evaluation criteria for shaft vibration under normal operating conditions, measured at or close to the bearings of coupled industrial machines. These guidelines are presented in terms of both steady runing vibration and any magnitude changes which may occur in these steady values. The numerical values specified are not intended to serve as the only basis for vibration evaluation since, in general, the vibratory condition of a machine is assessed by consideration of both the shaft vibration and the associated structural vibration (see the introduction to ISO 7919-1).

This part of ISO.7919 applies to coupled industrial machines with fluid-film bearings, having maximum continuous rated speeds in the range 1000 r/min to 30000 r/min, and not limited by size and power,comprising

• steam turbines;
• turbocompressors;
• turbopumps;
• turbogenerators;
• turbofans;
• electnc drives and associated gears, where relevant.

This part of ISO 7919 does not apply to large land-based steam turbine generator sets for power stations with outputs greater than 50 MW (see ISO 7919-2), nor to machine sets in hydraulic power generating and pumping plants with outputs of 1 MW or greater (see ISO 7919-5).