As an aside, I would think that helium and argon would leak faster, being monatomic.
the generators at work are filled with hydrogen (60 tonnes of steel, copper, and insulation spinning at 3,000RPM,and hydrogen provides less windage, and better heat transfer).
http://en.wikipedia.org/wiki/Hydrogen-cooled_turbo_generator
During maitnenance, we use tables like this
http://www.lacotech.com/ProductFiles/997300658_leaktechref.pdf
To work out if the leakage will be safe, when we are on either air or CO2 (displace air with CO2 before hydrogen filling, and reverse before maintenance)
We always use the same figure for air/nitrogen (but we never use nitrogen generally, as it's expensive).
the generators at work are filled with hydrogen (60 tonnes of steel, copper, and insulation spinning at 3,000RPM,and hydrogen provides less windage, and better heat transfer).
http://en.wikipedia.org/wiki/Hydrogen-cooled_turbo_generator
During maitnenance, we use tables like this
http://www.lacotech.com/ProductFiles/997300658_leaktechref.pdf
To work out if the leakage will be safe, when we are on either air or CO2 (displace air with CO2 before hydrogen filling, and reverse before maintenance)
We always use the same figure for air/nitrogen (but we never use nitrogen generally, as it's expensive).