conversion

[Scubakevdm]

Hey! Does anyone know off-hand how many cubic feet of gas are in a full 12 liter tank?

 

[UndrWatrDan]

Hey! Does anyone know off-hand how many cubic feet of gas are in a 12 liter tank?

0.4237759496554172

http://www.metric-conversions.org/volume/liters-to-cubic-feet.htm

What else do I have to do during this BORING training class that I'm sitting in!

 

[WarmWaterDiver]

Depends on if you're asking about 'actual cubic feet' which is easily expressed in volume of a virtually incompressible fluid, like water, - which you've received the answer for above, but since you specified 'gas' the answer probably isn't really what you're looking for, 'standard cubic feet' of a compressed gas at a given temperature and pressure, such as STP in engineering terms, or the even more confusing 'cubic feet of standard air' definition.

What are you really looking for?

 

[Scubakevdm]

I meant full, but thanks. I figured it out... 70 cuft in case anyone was wondering.

 

[WarmWaterDiver]

I meant full, but thanks. I figured it out... 70 cuft in case anyone was wondering.

At what 'full' tank pressure?

For example, a 12 L liquid volume tank rated say for being 'full' at 3500 PSIG or even better at tank rated to be 'full' at 300 BarG wil contain many more 'standard cubic feet' of compressed gas than say a 12 L liquid volume tank that is rated 'full' at 2400 PSIG.

 

[Scubakevdm]

I'm sorry. I used 2650 psi as the "full" pressure for the calculations I made. They are 200 bar tanks, I think so they would contain more, like 86 cuft or so at that pressure. Thanks.

 

[donacheson]

I'm sorry. I used 2650 psi as the "full" pressure for the calculations I made. They are 200 bar tanks, I think so they would contain more, like 86 cuft or so at that pressure. Thanks.

More than 70 cuft:

(2650[psia]/14.7[psia/std atm])x(12[l]/28.3[l/cuft]) = 76.4 [std cuft]

At 200 bar:

(200[bar]/1.01325[bar/std atm])x(12[l]/28.3[l/cuft]) = 83.7 [std cuft]

Both calculations assume the gas in the tanks to be an ideal gas. Actually, the capacity in standard cubic feet is a bit less. I don't know exactly how much less since I don't have a table of compressibility factors for air or any other gases handy.

 

[WarmWaterDiver]

You missed adding 14.7 to the 2650 psig to get it to psia, but the difference is negligible . . .

 

[freesharkdiver]

1 CFT = 0.02832 CBM and 1 CBM = 1000 Litres.
Therefore 12 CFT x 0.02832 = 0.33984 CBM
and 0.33984 CBM x 1000 = 339.84 Litres

Hope this helps
Freeshark

 

[freesharkdiver]

Sorry guys, misread the question... but conversion formula works anyway going th eother way around...