One of my vertical pumps vibration has increased from 8-10 mm/sec to 35 mm/sec. It was discovered by inspection technician in current route of data aqusition.

I checked the pump shaft, it was smooth in operation . I mean no swaying as it generally happens in vertical pumps. So I conclude that the pump is fine but there is no sound in motor bearings as well.

What could have caused it? Either the service liquid (Cooling Tower Blowdown)or else?

I have checked the motor stool bolts for looseness but found okay.
What checks should I make?
Thanks

Please give more information. For a start, at what frequency is this high vibration reading against actual RPM?
Where are you measuring?

can someone tell me how to add my vib. spectra.?

Thanks

The pump is at 3000 Rpm.
See attached sheet for vibration points and their amplitude.

Feroz,

What is the dominant vibration frequency?

Yahoo,

Why do you want to add spectra? What does that have to do with this discussion?

Walt

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This message has been edited. Last edited by: yahoo,

Are the amplitudes came back to normal ?
With these pumps, sporadic raise of 1X is often due to not enough flow when production shut the valve too much when they don't need enough water. That bring the pump to works under the curve and is very destructive. Another case could be a low level in the reservoir bringing a vortex and the pump breath air. When you came back to the pump, you found it quiet. So suspect an operation problem as these I mentioned.

J-Marc

Dear Mr J-Marc do you think it needs to open up the pump to check its bushes etc.?
Thanks.

This message has been edited. Last edited by: yahoo,

Copy and paste the Vibration spectrum to a word file then save it. While replying, select the "Add Attachment" (find the Word Doc) or save the plot as a *.jpg/png and attach.

See the axial reading? It had a 1431% Dev. Check the coupling condition and outrule vertical unit misalignment, possibly (most likely) lower shaft whipping or bent or product imbalance on the impellor??? You might want to correlate vibe data with fluid levels.

Feroz!
Elaborate your statement of the problem and pump as well, people are seeing ur pump as u...

After that Some thing can be said about it.