Reply to "Vibration at 5X NDE AND DE V for Centrifugal Pump"

The pump was overhauled as a part of routine maintenance ,there was no indication of vibration prior to overhauling. ok, then it should not be vibrating now right....then something changed...is the pump running backwards, just because the valve handle moved does not mean the internals moved, did something fall/collapse and block pump inlet, are flows and pressure normal, did you change impeller size

I assume "calibrated" means balanced the impeller

This are the main reasons I ruled out vane pass. I agree that as long as you did not change impeller size or design then there should not be vane pass, but if the suction or discharge of your pump is partially blocked you can see vane pass, it is created by hydraulic issues with pump performance. Like not enough liquid on suction side or restricted piping on discharge due to dirt buildup

This horizontally mounted centrifugal pump acts as a overhung rotor,having a bellow in the suction side and connected to motor using a flexible coupling.Pump has 2 angle contact bearing in DE and one radial bearing in NDE.

I carried out shock pulse test and found bearing pulse to be just under warning range shock pulse does not account for vane pass or 1x or 2x, it uses the ultrasonic range to identify faults at an early stage, very sensitive to flow/cavitation/lubrication defects

https://en.wikipedia.org/wiki/Shock_Pulse_Method

Dave

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