Argon / co2 question

[DaveO]

Another thread touched on this, but I didn't want to hijack that thread.

In MIG argon /co2 high pressure cylinders of shielding gas, does the co2 component exist in its gaseous or liquid state?

[res0r9lm]

Straight CO2 stays a liquid under moderate pressure

[Rambozo]

Another thread touched on this, but I didn't want to hijack that thread.

In MIG argon /co2 high pressure cylinders of shielding gas, does the co2 component exist in its gaseous or liquid state?

My initial take is that the two become a compound, and stay gaseous. This is just from the feel of the cylinder. You can feel liquid sloshing around in a CO2 cylinder, even if it's pretty low, yet you don't feel that in a C25 cylinder, even when full.

Next time I pickup a C25 cylinder, I guess I can verify that by inverting it, and crack the valve open a little.

[DaveO]

I searched a couple other welding forums with no conclusive results, and searched a couple MSDS sheets for "LIQU" strings with no results. I may give Airgas a call to see if they have a definitive answer.

[Kempy]

Straight CO2 stays a liquid under moderate pressure

100% Co2 at 68 F pressure is around 840 PSIG in liquid state in a high pressure cylinder, as you use the Co2 gas its pressure will not change in the tank until you used up all the liquid. The gas at the top of the liquid will stay at 840 PSIG as long as the temperature dose not change. Once the pressure drops below 840 PSIG at 68 deg. F or 20 deg. C it will keep going down till it is empty.
Once you mix Co2 with Argon they are both in a gases state. Now put 25% Co2 mix with Argon by pressure it should be 250 PSIG Co2 to 750 PSIG Argon at 68 deg. F but that is OK if you only need 1000 PSIG of C25/A75 mix. So in a 2400 PSI tank they put in 675 PSIG of Co2 in the tank and fill it to 2400 psig with Argon at 68 Deg. F with a temperature controlled blending machine this is what I was told by the welding supplier I get my gas from.
Next time I go into the mixing plant part I will ask if I can take any pictures.

[DaveO]

Thanks, Kempy, I'd be interested to see pictures.