What if the 40 was partially full and rated for 2400 psi?
Cylinder to Cylinder gas transfer (filling)
- Thread starter TexasMike
- Start date
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sheck33
Contributor
Doesnt matter if the tank is partially full or rated for a different pressure, the internal volume of a certain tank is a given.
If it is a 40 cuft tank rated at 2400 PSI the internal volume would be (40 x 14.7)/2400 = 0.245 cuft, obviously to still have 40 cuft at a lower pressure the internal volume has to be larger.
The formula i gave earlier is valid regardless of whether a tank is partially full or not, just plug in the internal volumes and the pressures of the tanks. The formula assumes constant temperature and ideal gas behaviour, conditions that hold well enough for slow filing and not to high pressures.
Well if the 40 had 600psi in it to start and the 80 3000psi
then 2/3 of 3600psi (3000+600) would be 2400 psi. final pressure.
and since the 80 at 3600 would have 20% more in it then we would be looking at 2/3 of 96 or 64cf
So the 80 would have 64cf and the 40 would have 40cf and they both would be at 2400 psi.
Am I close?
Now if I use the Sheck33 formula:
P1 x V1 + P2 x V2 = P3 x V3
3000X.392 + 600X.245=P3X.637
1323/.637=2077psi
Which would give 34.6 in the 40
and 55.4 in the 80
Is this correct?
P1 x V1 + P2 x V2 = P3 x V3
3000X.392 + 600X.245=P3X.637
1323/.637=2077psi
Which would give 34.6 in the 40
and 55.4 in the 80
Is this correct?
If the 40 brings 10 cf to the table at 600psi and the 80 brings 80 at 3000psi the there are 90cf total.
And since 34.6+55.4=90 then this must be correct.
OP
TexasMike
Contributor
Pug, your right....
after all of the above...I do need to find better uses of random brain power....
after all of the above...I do need to find better uses of random brain power....
sheck33
Contributor
No, this is not correct
sheck33
Contributor
Yes, this is the correct way to do it.
Math is easy once you understand.... NOT.... gggaaaakkkkk....
I would go out and fill tanks but everything is already pumped up (including the bank) in honor of Detroit Diver making a trip to the PNW.
Hey Sheck33... do you want to bring your calculator and join us?
OP
TexasMike
Contributor
When you getting together?
Perhaps not this season...but next year is a definite possibility....
Seems like for me, 2002 was the year of getting gear (to CPA, it's retirement planning...okay, not so much as having the cash, but the stuff to play in/with).
2003 will most likely be a few more outtings and trips.
Perhaps not this season...but next year is a definite possibility....
Seems like for me, 2002 was the year of getting gear (to CPA, it's retirement planning...okay, not so much as having the cash, but the stuff to play in/with).
2003 will most likely be a few more outtings and trips.
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