We are observing high frequency vibration in the steam turbine at 69,938 cpm. This individual frequency is dominant with amplitude of 5 mm/sec RMS. The same frequency is observed in hor, ver, axial directions.
Rated speed: 1500 RPM. MFR : Dresser Rand, turbine directly coupled to fan.
For vibration measurement we are using SKF microlog and accelerometer with magnet base mounting.
Fan vibration is normal and no presence of 69,938 cpm.
New equipment , we don't have previous readings...
Any suggestion shall be of help in identifying the problem..
Note : we have two identical equipments and both are having the same high frequency in turbine spectrum.
Thanks in advance