High Pump Bearing Temperature

[M. ENG 18]

Greetings everyone,

I have an overhung pump driven by motor(45kw).
This pump is new installation in our plant.

During the 4 hours mechanical run test ( first run ) by water at ambient temperature. The DE ( outboard) bearing recorded temperature between 76 to 79 C and NDE bearing recorded 71 C (after completing the 4 hours test). All vibration readings with the acceptable limits.

The bearing house is equipped by cooling water supply and during the test this CWS was lined up.

As per the vendor manual highest temperature is 82C, please find the following quote:
“(Based on the specified operation condition and ambient temperature 43C for ring oiler, oil sump temperature below 82 is expected.

The question?
Is this temperature consider high and not accepted especially it is very close to the maximum value recommended by vendor. Also, I wonder how the bearing temperature will be after the plant start up, because the original pumped liquid is water with normal temperature at 195 C.

Your valuable technical feedback is highly appreciated.

 

[Paul_R]

Pumps have high axial and radial thrust at low rates of flow. Are you operating it at your duty point or at a very low flow, say below 20% of the pumps best efficiency rate of flow?
If you are at a low flow move as close to your duty point as possible and see if your temperatures now become normal.

 

[M. ENG 18]

Thanks very much for your reply. I will consider this advise