MSI's ODS testing suggested modifications for the baseplate of a Boiler Feed Pump that greatly reduced the max vibration amplitude at the outboard bearing housing, solving the problem.

Ring-Section-Boiler-Feed-Pump

Cross-Section of Ring Section Boiler Feedwater Pump.

 

BFP-FFT-Before-Modification-1024x689

FFT plot of an accelerometer mounted to the outboard bearing housing before modifications.

 

BFP-Before-Modification

Boiler Feed Pump baseplate before modifications.

 

The root cause was excessive flexibility at the baseplate due to softness/ delamination of the internal grout.  This phenomenon originated due to the looseness of the anchor J-bolts.  After all suggested modifications were performed on the baseplate, the maximum vibration amplitude at the OBB housing in the horizontal direction was greatly reduced.

 

BFP-After-Modification

Boiler Feed Pump baseplate with modifications.

 

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FFT plot of an accelerometer mounted to the outboard bearing housing after modifications.

 

Overall-Train-Animation-242x300

Click to view ODS animation showing soft foot between the baseplate and grout. The separation can be seen in the +y corner near the outboard bearing (top right and bottom left quadrants).

 

For a more in depth paper on this case study presented at the International Pump Users Symposium, click here.

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