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Dissolved gas in labricant oil

M matteobrescianiMember
we have registered elevated concentrations of hydrogen dissolved in the oil of lubrication gas turbine (SHELL TURBO CC 32).
The hydrogen, is used as cooler for the alternator. The Hydrogen escapes from the oil seal and dissolved in the oil.
A sample was taken in seal point and the relative hydrogen concentration was 45 [ppm], while a sample taken in the oil tank (at rest) show a concentration of 350 [ppb].
I'm still waiting to the foaming test and the air release test.
The viscosity and the TAN are under the limits.
Does anyone know if are the limits for the dissolved gas in gas turbine oil? what kind of failure could happen whit an excessive quantitative of dissolved gas?
Does the hydrogen concentration that I wrote are dangerous?
I hope that anybody has understood that I meant.
Excuse me for my bad English, I write from Italy.
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L lancelewandMember
The hydrogen concentrations are extremely low in your oil and do not represent a hazard. Usually there is a partition of about 18-20:1 between the hydrogen in the oil and the hydrogen in the headspace so in order to reach the lower explosive level for hydrogen you would have to have over 2000 ppm hydrogen in the oil to create an explosive atmosphere.
E electricpeteMember
Hydrogen and other combustible gasses in oil is a common occurence for power transformers. The partition can be predicted in steady state from the Oswalt coefficients as was mentioned.

Similar to the comment above, I have heard below 1,000 ppm, there is no concern for explosive gas mixtures.

Also at those low levels I don't think it would interfere with lubrication. But I have heard mentioned a phenomenon of cavitation in sleeve bearings which is sensitive to the type and amount of dissolved gases. Don't know much more about it.
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