CraigAClark Thanks for the lesson! So in your opinion is the 80% O2 we get down here safe for Nitrox blending? Granted it's safer from and explosion point! But do you think my fears of Co2 and Argon are justified or just down right silly?
Even if you just use draeger tubes (which I am suspect of their accuracy), get the gas tested. I would never give anyone a "go ahead" without an analysis. If the gas comes back with acceptable levels, then just do your calculation based on the 80%. I assume you already do this.
Regarding the Nuvair, I assume you already have an H.P. compressor? UBS used to run a system off of h.p. storage to supply the l.p. gas for their membrane. Obviously, that pressure had to be reduced to membrane pressure (max for a permea is 250, most of the technology used today, as with the Nuvair is 100 psi or less). Huge icing problem on the high-flow regulator. BTW, you don't need a nitrox stick with a membrane. I would suggest that you find a proportional thermostat to control the heater unit. they use a cheap non-proportional Johnson Controls model 419. Also, I will never sell a non-water cooled system again. Make sure, if you decide to go membrane or continuos blending, completely tear down your compressor, thoroughly clean it, rebuild it and use a suitable synthetic oil. Remember, there is absolutely no such thing as "breathing air" oil.