API 617 mechanical run test. probe is located on the drive end. compressor runs at max. continuous for 4 hours then up trip speed, then ramps down. so the plot represents vibration during its decel. the explanation we received from supplier was that this was "test conditions", but we would...
zekeman, this is actual plot from a centrifugal compressor on test about 2 weeks ago. this was the first bundle tested. the second bundle, exactly the same in theory, does not show this at all.
Okay, I mispoke. Here is the plot in question. We suspect this is the 2nd critical, which is near our operating range. The lateral report predicted 2nd critical to be in the 12,000 rpm range. What other explanations woulc produce this...
