14:55 Dec 7, 2009 

Thanks for the comments. I did consider whether it could be some kind of unit, but now I'm inclining towards "pressure levels", because further on in the document the wording is "ο υπέρθερμος ατμός του σε τρείς βαθμίδες πίεσης ...".

10:41 Dec 7, 2009 

A guess really, as I can't find anything to back this up, but in the context could it be construed as three atmospheres, i.e. 45 psi?

10:11 Dec 7, 2009 

I agree with you, Dylan, as regards "superheated" and probably "pressure levels", too.