Volume of Al 80

[Culcuhain]

the only way to empty completely would be in a vacuum as the ambient pressure at 14.7psi is still filling the tank.

 

[Insta-Gator]

Is this the "BP/W vs Poodle Jacket" replacement thread?

 

[4sak3n]

the only way to empty completely would be in a vacuum as the ambient pressure at 14.7psi is still filling the tank.

Thank you but that doesn't answer my question. I am very well aware that a pressure differential is needed for gas to flow from one container to another.

Also, at what pressure does helium stop approximating an ideal gas and start behaving as a real gas?

 

[ianr33]

Also, at what pressure does helium stop approximating an ideal gas and start behaving as a real gas?

Helium isn't even a gas. It's a supercritical fluid ! (At least above 5.19K and 2.24 Atm)

Critical point (thermodynamics) - Wikipedia, the free encyclopedia

 

[4sak3n]

Wow! Cool!

:thumbs-up

I have some reading to do. :cool2:

 

[Danseur]

Helium is a tad different at pressure as there is a compressibility factor. I don't recall the math, and as was alluded to, it's an ideal gas law.

In practice it's more a "fudge factor".

 

[Wookie]

When I compress helium, nitrogen, and oxygen into a cylinder using the ideal gas laws, I come out pretty close to the mixture I was trying to make, certainly within the error factors of the analyzer, and the various gauges I use to measure said mixture. So, bantering about how much gas you can fit in the gas tank is a fun exercise to work the mind, in real life it just doesn't matter. You can't effectively measure the differences anyway.

 

[mala]

Thank you but that doesn't answer my question. I am very well aware that a pressure differential is needed for gas to flow from one container to another.

Also, at what pressure does helium stop approximating an ideal gas and start behaving as a real gas?

no gas is an ideal gas.
the combined gas "laws" only work at relatively low pressures and normal temps.

each gas is unique and does its own thing when you squash it.
the atomic mass ,its molecular comp and its attractability to other similar molecules are all factors.

the compressor guys call it the fudge factor.

some german? scientist who's name eludes me has a set of conversion tables for most gases .

 

[4sak3n]

no gas is an ideal gas.
the combined gas "laws" only work at relatively low pressures and normal temps.

each gas is unique and does its own thing when you squash it.
the atomic mass ,its molecular comp and its attractability to other similar molecules are all factors.

the compressor guys call it the fudge factor.

some german? scientist who's name eludes me has a set of conversion tables for most gases .

Thank you but that doesn't answer my question. I am very well aware that there is no such thing as an ideal gas in nature.

Also, at what pressure does helium stop approximating an ideal gas and start behaving as a real gas?

​

Underlining for emphasis. I very, very deliberately and consciously phrased it that way to avoid nitpicking.

 

[Danseur]

Ok, a standard 3000 psi AL80 nominally holds 77.4 cubic feet of gas. Period.