Centrifugal Compressor Vibration
Centrifugal Compressor Vibration
(OP)
Hi,
I have also posted this in the Acoustic & Vibration Engineering Forum.
We are trying to commission a new motor-gear-centrif, gas compression train. We have an issue with the vibration levels at the Compressor Drive End. As the machine runs up to speed (16,000 rpm driven) the shaft centreline plot (both DE & NDE) is a near vertical line rising ~130 microns. Once on its centre line the NDE vibration is a constant ~12 microns (primarily 1x & round orbit) as is the DE. However the DE amplitude continues to rise over time flattening out at ~39 microns (primarily 1x & round orbit)after 90 minutes.
The machinery OEM is blaming nozzle loads due to the piping growing, but my experience tells me that nozzle loads, if large enough to cause problems, will apply a pre-load to the bearing resulting in an elliptical orbit.
FYI. The machine alignment is within OEM spec and the piping certainly looks well enough designed that loads would not be transferred back on to the nozzles.
Any ideas? I am looking at Morton Effect.
Thanks
AD90
I have also posted this in the Acoustic & Vibration Engineering Forum.
We are trying to commission a new motor-gear-centrif, gas compression train. We have an issue with the vibration levels at the Compressor Drive End. As the machine runs up to speed (16,000 rpm driven) the shaft centreline plot (both DE & NDE) is a near vertical line rising ~130 microns. Once on its centre line the NDE vibration is a constant ~12 microns (primarily 1x & round orbit) as is the DE. However the DE amplitude continues to rise over time flattening out at ~39 microns (primarily 1x & round orbit)after 90 minutes.
The machinery OEM is blaming nozzle loads due to the piping growing, but my experience tells me that nozzle loads, if large enough to cause problems, will apply a pre-load to the bearing resulting in an elliptical orbit.
FYI. The machine alignment is within OEM spec and the piping certainly looks well enough designed that loads would not be transferred back on to the nozzles.
Any ideas? I am looking at Morton Effect.
Thanks
AD90





RE: Centrifugal Compressor Vibration
Has the OEM made a specific remark about your piping configuration?
RE: Centrifugal Compressor Vibration
I am trying to stay one step ahead.
Thanks
AD90
RE: Centrifugal Compressor Vibration
What is the bearing clearance - have you added the bearing clearance to the shaft centreline to see where the shaft settles when on load?
If this is a new machine, what does the supply contract say about vibration - API 617 suggests a limit of 22 microns for a new machine running at 16000rpm (runout needs to be added to this, say 28 microns total)
RE: Centrifugal Compressor Vibration
AD90
RE: Centrifugal Compressor Vibration
RE: Centrifugal Compressor Vibration
AD90