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        New Message Board Archives >> 2005 Cluster Headache Specific Posts >> Cali., Arizona, New Mexico peeps.....o2 and heat??
        
(Message started by: E-Double on May 31^st, 2005, 4:42pm)

Title: Cali., Arizona, New Mexico peeps.....o2 and heat??
Post by E-Double on May 31^st, 2005, 4:42pm

Nevada, etc.........

Anyone have problems keeping tanks in your vehicles???

A q? for a newbie

Title: Re: Cali., Arizona, New Mexico peeps.....o2 and he
Post by marlinsfan on May 31^st, 2005, 4:58pm

E,

I live in Florida and I am also a part-time scuba instructor. O2 tanks are much like air tanks we use when diving, in that they contained highly pressurized gas.

When the gas heats up (as when it stays in a car for a long time), the molecules in the gas get excited and start to increase speed, causing the pressure in the tank to increase rapidly.

The valve on the O2 tank will have a bleeder that will burst when the pressure in increased to a certain degree. For scuba tanks, it will pop at 150% of pressure. So, a regular scuba tank that will hold 3000 psi will pop at 4500. On a hot day, pressure can get there in less than one hour.

I don't know what pressure rating in O2 tanks are, nor what settings the valves have, but I would not recommend keeping the tank inside a closed car.

Title: Re: Cali., Arizona, New Mexico peeps.....o2 and he
Post by Bob P on May 31^st, 2005, 5:07pm

I left a tank in the car in San Diego a few weeks ago. Outside temps in the 80's. Left the car window cracked and had the tank in the shade.

Sure don't think I'd leave one in the car on a 100 degree day in Arizona!

Title: Re: Cali., Arizona, New Mexico peeps.....o2 and he
Post by E-Double on May 31^st, 2005, 5:09pm

Thanks I'll send the dude over here to read ;)

Title: Re: Cali., Arizona, New Mexico peeps.....o2 and he
Post by BikerBob on May 31^st, 2005, 6:43pm

on 05/31/05 at 16:58:11, marlinsfan wrote:

So, a regular scuba tank that will hold 3000 psi will pop at 4500. On a hot day, pressure can get there in less than one hour.

I don't know what pressure rating in O2 tanks are, nor what settings the valves have, but I would not recommend keeping the tank inside a closed car.

O2 tanks at full capacity are only 2000 psi. The regulator goes up to 3000 psi.

Bob

Title: Re: Cali., Arizona, New Mexico peeps.....o2 and he
Post by marlinsfan on May 31^st, 2005, 9:14pm

THe hydrostatic testing done every 5 years on all compressed gas tanks test at 2x the PSI marked on them.

The danger with tanks in a car is that if the valve release pops, the tank can take off like a bullet.

I wouldn't do it....

Title: Re: Cali., Arizona, New Mexico peeps.....o2 and he
Post by Mr. Happy on May 31^st, 2005, 11:46pm

I never worry about ye olde O2 saftey tank stored in the aft of the party van. It's the refilled propane tanks in transit for the gas grill that make me nervous.

Dopey me.
RJ

Title: Re: Cali., Arizona, New Mexico peeps.....o2 and he
Post by nani on May 31^st, 2005, 11:47pm

The trunk stays a lot cooler than the interior...the sun is the real killer. I swear it's at least 140 degrees in there...

Title: Re: Cali., Arizona, New Mexico peeps.....o2 and he
Post by Jasen on Jun 1^st, 2005, 12:25am

Had one in my van during our 2 days of nearly 90* last week, not a problem.

Title: Re: Cali., Arizona, New Mexico peeps.....o2 and he
Post by Boyce on Jun 21^st, 2005, 3:41pm

I've been carrying D's and E's in my car all of May and June this year.....I crack the window and try to keep the tank in the backseat out of the direct sun, but have had no problems yet.....

Title: Re: Cali., Arizona, New Mexico peeps.....o2 and he
Post by Ueli on Jun 21^st, 2005, 7:27pm

The Ideal Gas Law:

p * V = cons * T

with p = pressure
V = volume
T = absolute temperature, measured in °K = °C + 273 or °Rank = °F + 460
cons = a constant that contains the universal gas constant, Avogadro's number, and of course conversion constants for the weird units you insist to use.

Oxygen O₂ is near enough to the ideal gas to use this law with only a small error.

Therefore, starting from an ambient temperature of 300°K (27°C, 80°F) you need to heat up the tank to 450°K (177°C, 350°F) to get a pressure increase of 50% (which is still on the save side, but the temperature would be more than needed to fry an egg).

Another oxygen horror story debunked. ;)

Ueli [smiley=smokin.gif]

Title: Re: Cali., Arizona, New Mexico peeps.....o2 and he
Post by Kevin_M on Jun 21^st, 2005, 7:48pm

Thanks Ueli, for using the knowledge that's... out there.
8)
*so, if it actually is hot enough to fry and egg on the sidewalk, The O₂ will be ok, among a host of other problems though.

Kevin M