Razorblade
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Does a steel tank with a service pressure of 3500 psi have any effect when mixing gases? Why is it any different to mixing gases in 2400 psi tanks? Don't the gas laws remain ideal for 3500 psi?
HP vs LP
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SimonN
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No. Outside of the USA (yep, there are places outside of the USA where people dive) 232 bar Fabers are pretty standard cylinders. We call these low pressure. High pressure cylinders ar 300bar which is around 4500 psi.
Outside of the US you do not really get 2400 psi cylinders. And, we dive mixed gasses as well.
It isn't and different. Ideal gas laws start breaking down around 260bar (apparently) which is around 3800 psi.
The Ideal gas EOS (equation of state) is not accurate for real gases. Anything greater than 15 ATM (~200 psi) and the behavior predicted by the Ideal EOS will start to be greater than 1%. (it depends on the gas, temperature, and volume it is being jammed into).
At 3800 psi air will be off about 7% and helium 10%
omar
At 3800 psi air will be off about 7% and helium 10%
omar
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Razorblade
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since you're gonna be off either way it doesn't really matter if the gas mixing is done in 3500 psi tanks or 2600 psi tanks? It's just gonna be slightly more off in the higher pressure tanks but does this present a problem?
Yes it does... the behaviour of real gases becomes very much different to "Ideal" behaviour long before one gets to the 3500 psi fill pressure.
Check this out van der waals
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