We are investigating the cause of a bearing failure on one of our boiler feed pumps, it is a five stage, Kingsbury type thrust bearing, split bushing "collar" lubricated pump.The oil used is Texaco R7O 68.We sent the sludge for analysis (an oil sample could not be obtained after failure,. Results shows the presence of Phosphorous and Potassium (19 and 18 ppm respectively.Any thoughts where this came from?, the detergent Mulsolv was used for cleaning, and it is suspected that it was not flushed out properly.

How was the sample tested (spectrography)? This test is only indicative of the content of particles up to 5 microns. You should probably contact the facility who conducted the testing and have them explain the results, but I can tell you that typically, Phosphorous and Potassium are both commonly seen as an additives depending on the product. Texaco should be able to tell you more about what is in this particular product and whether it would be considered a normal concentration in your sludge.

Hope this helps!

Thank you for such a quick response.Yes only a spectrography test was done.we cannot confirm if there was water present, most of our research says that water must be present for Phosphorous and Potassium to be present as contaminants.The OB bearing failed catastrophically, and is all black in colour , the Inboard bearing was not discolored only scoured.We were thinking the cleaning agent "Mulsolv"was mixed with the oil and broke down the oil, eventually causing failure.
Note ; this area of analysis is all new to us , any information or references is greatly welcomed !

Sorry for the slow response as I have been on the road. What you have provided here is very little data, however we can speculate a bit from it: the OB bearing suffered a catastrophic failure. It is black, the discoloration most likely from thermal energy. It is also likely that this heat was the result of friction. This friction could have resulted from a breakdown in the lubrication barrier of the oil. If this occured, it may have been caused by the ingression of a contaminant, such as the cleaning agent you mentioned. This contaminant could have reduced the viscosity of the oil. Viscosity is the main property of the lubricant which maintains the separation of the rotating and static surfaces. If reduced, contact, friction, and heat could have been the result. I understand that this is the direction that you are leaning, however, as you can see from my previous statements, there are a LOT of "ifs". What you are really wanting to accomplish here is Root Cause Bearing Failure Analysis. This requires that a highly disciplined process be adhered to which assumes NOTHING. Assuming is an easy trap to fall into, but must be avoided at all cost in order to arrive at the most likely and objective conclusion. SKF is one provider of this training (one that I would recommend) and I'm sure there are many others as well. If you are really serious about finding the root cause of this as well as future failures, I would highly recommend that you seek formal training in this field, or consider hiring a consultant.