Recently we encountered a failure in one of the Boiler feed water pump. Observations were as below.
1. Pump tripped after running for 30 sec when it reached its full disch pressure of 100kg/cm2G.
2. Trip was due to high bearing vibration on NDE side.
3. Rotor was moved towards DE by about 2mm.
4. Rotor was seized( could not rotate with hand).
5. NDE oil decolorised slightly.
6. upon dismantling we found that NDE bearing inner race was seized to shaft. NDE bearing was totally damaged.
7. DE bearing was fine and no change in oil color too.
8. While operation, discharge valve was fully closed( according to operations min circulation as well as balancing lines were fully open).
Online probes not able to provide required spectrum.
Now we are struggling to analyze the cause. Pls suggest the way forward and also if you have link to similar failures.