Hi,
I have also posted this in the Gas Compression 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 Gas Compression 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
