Oil Coking limits 2

[peteroates]

We use magnetic face seals in place of lip seals on a wide variety of applications, usually on pumps but alos gearboxes and other equipment. The only factor limiting the speed of operation is the heat generated and this cokes (carbonises)the oil.
I am looking for information on what the coking temperatures would be for a range of proprietry oils. The oil companies do not seems to give this information on their data sheets and a brief trawl of the internet failed to get anything meaningful.
Does anyone have any pointers they could give me so I can find the coking temperatures, or am being too simplistic and getting into a very complicated area?

 

[Skogsgurra]

I hear anything from 120 to 150 centigrades allowed before getting problems with the oil in the bearings. I have never seen that in print, but it is something that the SKF guys mention now and then. I also have the impression that they never want to go to the upper limit but regard the lower limit (120) as something that should not be exceeded.



Gunnar Englund

http://www.gke.org

 

[blfarrar]

The data I got when working as a marine engineer from the "old guys" was 120deg C - after that the oil carbonised - everthing in a marine engine with oil lube to white metal is kept below this value as the carbonisation of oil blocks oilways.

As for your seals - dependant on what the application is labrinth seals (no contact) are use in marine steam turbines for high speed applications & can be successfully adapted for many other "problem" areas.

I'eve used them for rod seals on pneumatic cylnders on plastic thermo forming machines where standard nitrile & viton seals have failed.