This document is applicable to land-based gas turbines, steam turbines and generators (whether
coupled with gas and/or steam turbines) with power outputs greater than 40 MW, fluid-film bearings
and rated speeds of 1 500 r/min, 1 800 r/min, 3 000 r/min or 3 600 r/min. The criteria provided in this
document can be applied to the vibration of the gas turbine, steam turbine and generator (including
synchronizing clutches). This document establishes provisions for evaluating the severity of the
following in-situ, broad-band vibration:
a) structural vibration at all main bearing housings or pedestals measured radial (i.e. transverse) to
the shaft axis;
b) structural vibration at thrust bearing housings measured in the axial direction;
c) vibration of rotating shafts radial (i.e. transverse) to the shaft axis at, or close to, the main bearings.
These are in terms of the following:
— vibration under normal steady-state operating conditions;
— vibration during other (non-steady-state) conditions when transient changes are taking place,
including run up or run down, initial loading and load changes;
— changes in vibration which can occur during normal steady-state operation.