thanks for your replies and apologies if it was posted in the wrong place. just a non-technical person, with a problem, stubbled on the website and hoped i could get a reply...
I have a (faulty!) cylinder filled with compressed air at 2,000 psi which leaks at a rate of 1litre/minute at sea level. What would be the expected rate of leak at an altitude of 8,000ft? thanks for your help.