CO2 tank worries

[DanOmite]

I am heading home (LA), as I just graduated from college. I am currently at 7,000 feet and my destination is at sea level (just about). I am worried about taking the CO2 tank down in elevation. I will be driving through desert, so the temperature will probably rise, even though it has been really wet and cold up here.

I recall from chemistry the relationship PV=nRT, which tells me, I should expect the pressure and volume to vary in the CO2 tank as the surrounding temperature varies (assuming the number of gas molecules remains constant—reasonable). So, should I just empty the tank or just keep it in the trunk with all my other crap and hope nothing bad happens? I don’t think the temperature will be too extreme, since it is cold and rainy everywhere in Arizona and central to south California right now. Also, I will be going down in elevation.

Thanks

 

[rmullins]

I'm no scientist but unless your tank is 100% filled I can't imagine any altitude/temperature changes will be drastic/quick enough to cause anything to happen

 

[theredben]

The key is that the CO2 cylinder is not all liquid. As the ambient temp changes the proportion of Liquid/gas changes accordingly. No pressure change.

 

[theonetrueruss]

you wont have a problem.. the tank is filled by weight.. elevation does not affect weight.. even if the pressure were to change it would still just be the pressure as though it were filled wherever you are.. no problem

 

[Catt22]

The key is that the CO2 cylinder is not all liquid. As the ambient temp changes the proportion of Liquid/gas changes accordingly. No pressure change.

The vapor pressure of the CO2 most certainly will increase at higher temperatures:

http://www.s-ohe.com/carbon dioxide.html

 

[theredben]

My mistake, I was thinking about contant pressure when WEIGHT changes, not temp. If the tank was fresh filled, just let out 1/2 lb or so of CO2

On a side note, with the whole global warming thing, it is now much harder to find information on "carbon dioxide temperature change"

 

[jebsterr]

The tank should have a blow off valve on the back of the main valve body to vent any overpressure. CO2 is stored as a liquid/gas. As pressure goes up more liquid is created, as pressure goes down more gas is created. As long as there are no defects to your tank like rust, then it should be fine. If your worried about it then vent it, its only CO2.

 

[BrewMoreBeers]

Prior to venting you are going to need to pay a carbon tax for your contribution to "global warming". Send me a six pack of your HB and we will call it even.

 

[Ohio-Ed]

Be careful if you choose to vent some of the contents.
I took a 20# cylinder to be filled this week. It still had about 5# of co2 in it so they had to vent it before refilling. They just opened the valve to vent, then re-filled the cylinder. I picked it up by the neck and carried it to the car. On the way home, my fingers started bothering me just bit. Four days later, my ring finger still feels blistered... I think I got a mild frostbite. DOH!!

 

[Dynachrome]

The tank should have a blow off valve on the back of the main valve body to vent any overpressure. CO2 is stored as a liquid/gas. As pressure goes up more liquid is created, as pressure goes down more gas is created. As long as there are no defects to your tank like rust, then it should be fine. If your worried about it then vent it, its only CO2.

I wouldn't want it venting in a well sealed automobile

 

[hotbeer]

You know the welding supply trucks with tanks of various gasses seem to do well with the tanks sitting in the sun all day during their delivery and pickup routes around here.

And going from higher elevation to lower elevation puts most everything in your favor. However if you do hear the safety cap blow, then get out of the vehicle so you don't chance smothering for lack of oxygen.

Extremely unlikely there'll be an explosion. You'll likely have a hard time getting the bottle to rupture even if you try.

Zombies are afoot. Never mind!