Word of warning : Don't Leave Full CO2 Tanks in Hot Car!

My Co2 Story:

My neighbor who works fire suppression offered to bring home a 5lb tank. He put it in his sedan, then got called back inside work for a while. He got back in his car and proceeded to drive away. He started to feel bad, and difficulty breathing. He was able to pull over and get out of car just before beginning to black out, took out his cell and dialed 91_. He started to feel a little better, and then saw the tank in the back seat all frosted up. He rolled down windows/opened doors to air out the car for a while, then got back in to drive home, and it started again(Co2 absorbed in fabric?) He's ok, but only because he was able to pull over so quickly. I told him that I would have a hard time explaining to his wife that he died just so I could have bubbles in my beer.

McKBrew said:

People use CO2 tanks for filling tires, esp in off-roading applications (something I just recently learned).

I imagine people have them inside vehicles all the time in that application. Not saying there aren't risks, but they can be mitigated.

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They are great for reseating a bead on your tires or even running air power tools. I spent many summers with a 20lb Co2 tank in my jeep. Mine was strapped to the roll bar in the baking desert sun. I never had a disk blow or have a single problem. None of my friends who used them did either.

Co2 is different than a scuba tank. The liquid CO2 in the tank change air as the pressure is released. This is why gauges on tanks are next to worthless. They measure pressure not the liquid. This evaporative process slows the pressure release rate meaning that a CO2 tank will not become a high speed rocket like a scuba tank would in the rare event of a valve decapitation.

They are pretty much the same as fire extinguishers which people carry around in their cars all the time.

Heres the place i got the tank from.
http://powertank.com/

The stories where the disk blew sound like an over filled tank to me. That's the only time i've ever heard of a tank bursting its disk.

I witnessed a safety-disk burst on a nitrous tank in a car once. The owner forgot and left the bottle heater on...The pressure built up to 2500-3000psi(about where the factory disks are set to burst). 100 people in the parking lot around the car and nearly everyone jumped out of their shoes.


It could be worse. The disk could fail to blow off:


CO2 is at a much lower pressure though, right? It would probably still do a bit of damage I would assume.

ColoradoXJ13 said:

PV=nRT
live and learn.

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Haha like my chem proff used to say...chemistry is a gas

or acetylene tanks http://www.autos.ca/forum/index.php?topic=76844.0

had the same thing happen on a paintball tank

Simply put,

MY GF got a full tank from a coworker and put it in her jeep for a couple hours while at work in AZ. Came out and the jeep was still full of CO2 and she had to let it air out for a few minutes before even getting in the vehicle. CO2 all released in a confined space like that can be deadly, if you are ever around when one decides to go open a window or go outside, it can suffocate you!

NitrouStang96 said:

Easy solution, guys:

I have a 15lb nitrous tank in my trunk 24/7. It's been in there for 8 years. In the middle of summer in South Carolina in months of 100 degree days, I kept a beach towel and a small container of water in the trunk. A soaked towel draped over the top is all that is needed to keep the bottle at normal temps, but if you're really scared (or in my case, need to cool the bottle fast), a little ice water is a quick trick.

When a car is parked outside in the hot sun all day long on a 100+ degree day... I have no idea how hot it must get in the car, but my bottle stayed in usable temps, so it was no where near blowing the safety valve.

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Agree. Sounds like to me the pressure relief was weak and not the tank being over filled. You should never have a burst disk rupture on CO2 tank at 100f in a car. My math shows me at least 275f might do it but uncertain. But at 100f its safe in a car filled to max.

Im not sure what type of tanks everyone has but I drive an HVAC van in southern California heat. I have Co2, Nitrogen, and Oxygen as well as R-22, R-410a, and R 404a. Ive never had any of this happen to me. In fact to do my job it requires carrying this in your vehicle. I have seen some of the Empty Tanks that Homebrew stores sell and I wouldnt trust them. Go to AirGas or another welding/gas store and buy one of their tanks, when its empty they exchange it for a full one, when they full the empty bottles all valves are inspected and tested and are industrial quality and not some china no name brand stuff.. Industrial tanks can take the heat.

CO2 tanks are not to be fooled with. I used to play paint ball alot, I had one tanl that was giving my gun fits. I unscrewed it and flipped it with the valve up to look at it and determin the problem. Suddenly the burst disk and another piece of brass popped out propelling it from my hand into my foot. A short trip to the hospital later, I found out I had 4 bones in my foot broken.
According to my tanks manufacturer [brass eagle] This was most likely from overfilling at the welding store that filled my tanks, and the fact that the tank was bought 2nd hand, was several years old [9 at the time], never maintaned[wtf is this white stuff on my tank valve] and stored improperly [rattled around in my car trunk in the 3 years I had it].

This tank was only a 20 oz. I wouldnt want to see a snafu with an overpressurized 5lb tank

MrRoboto said:

Im not sure what type of tanks everyone has but I drive an HVAC van in southern California heat. I have Co2, Nitrogen, and Oxygen as well as R-22, R-410a, and R 404a. Ive never had any of this happen to me. In fact to do my job it requires carrying this in your vehicle. I have seen some of the Empty Tanks that Homebrew stores sell and I wouldnt trust them. Go to AirGas or another welding/gas store and buy one of their tanks, when its empty they exchange it for a full one, when they full the empty bottles all valves are inspected and tested and are industrial quality and not some china no name brand stuff.. Industrial tanks can take the heat.

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I did HVAC for 15years and never heard of co2 tanks blowing, I'd keep 2 or 3 of them on the truck. One guy was blowing down coils on a roof and when he took the tank down it froze to his arm for 2nd degree burns.

I had a 20 oz paintball tank blow a disc in the back seat of my truck while I was at a McDonald's drive-thru window. That was interesting. I assume it was overfilled since this happened at night with the AC on. That, and I got it filled at Academy Sports, where random Joes do the tank filling. I get my 5lb tank exchanged at the local welding shop, where I have infinitely more confidence my tank is being filled my someone who knows what's up. I still wouldn't want it left in the heat for any length of time.

I opened up the valve with the wife in the car hoping for just a little spurt but I forgot there was no regulator on the tank and it nearly deafened us both. Not my proudest moment

As an avid offroader I keep a 20lb powertank in my jeep 24/7 it has sat through Oklahoma/Arkansas summers (several with temps at 110 or better) and now two North Carolina summers. If your burst disk goes someone messed up. I always use a fire extinguisher place and not a welding shop. For some reason I trust the guys who are crazy regulated over the guy huffing welding fumes.

I can speak from personal experience. I used to go paintballing all the time and co2 is used for alot of the guns to propel the balls. heat + co2 = burst disc blown.

co2 pressure is heat dependent. Most co2 tanks are good to about 1800psi.

It's not a CO2 tank, but my coworker and I almost died transporting some human tissue grafts on dry ice (frozen CO2). We were taking the grafts to a surgery about an hour away, and the doctor didn't use the grafts, so we left the grafts in her little Honda Fit while we went to lunch after the surgery. These are boxes filled with 80 lbs of dry ice, intended to keep the grafts at -40 C for about a week, so stopping for lunch wasn't an issue. On the way home we got about 15 minutes into the drive when both of use started to have a lot of trouble breathing. At first I thought I was having a heartache or something, and then I realized both of us were in trouble, and then my clogged mind suddenly realized what was happening, and I rolled down our windows. It was like someone took a clamp off my lungs and we could breathe fine. We pulled over for a few minutes to literally catch our breath, and then drove home the rest of the way with the windows cracked. But hey, now we made it into our companies safety manual on how to deal with dry ice!

I'll say (if someone hasn't already said it) to be careful if you put it in your car on a super cold day and have an extended drive after picking it up. I picked my first tank up from the local cylinder gas company and then put it on the floor on the passenger side of my car. After driving around with the heat on high and full blast (it was -21F at the time here in Michigan) for about an hour, all of the sudden the relief valve blew and shot Co2 all through the cabin of my car. I had to hold my breath, roll down the window and pull off the highway immediately, and even then I felt super light headed. There was about an inch of ice on the passenger side of my car after it was finished blowing. I'm still scared every time I hook up a new keg haha

backsideslash said:

I'll say (if someone hasn't already said it) to be careful if you put it in your car on a super cold day and have an extended drive after picking it up. I picked my first tank up from the local cylinder gas company and then put it on the floor on the passenger side of my car. After driving around with the heat on high and full blast (it was -21F at the time here in Michigan) for about an hour, all of the sudden the relief valve blew and shot Co2 all through the cabin of my car. I had to hold my breath, roll down the window and pull off the highway immediately, and even then I felt super light headed. There was about an inch of ice on the passenger side of my car after it was finished blowing. I'm still scared every time I hook up a new keg haha

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Tank must have been overfilled, or had a defective blowout disk. According to the chart in post #96, a properly filled tank should not have its pressure relief disc blow out at less than about 130°F.

Brew on

doug293cz said:

Tank must have been overfilled, or had a defective blowout disk. According to the chart in post #96, a properly filled tank should not have its pressure relief disc blow out at less than about 130°F.

Brew on

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It happened to me just a month ago. No way does the car get that hot for the valve to release. You see these tanks on the outside of trucks all the time. I'm certain, they get a lot hotter than that with out any problems. If that were really the situation, there would be a lot more stories like this.

When I took mine back, the guy said we either over filled it, or the pressure relief disc blew out. Turns out it was the latter and he showed me the disc. They refilled for free.

Too bad it wasn't N2O when it blew.

wizardofza said:

Yep, went and exchanged my C02 tank yesterday during my lunch break and left it in the backseat of my truck.

I came out after work and I knew something was strange when all the papers that were originally in my back seat were all in my front seat! That, and the tank had condensation on it, not to mention it was empty.

I took the thing back to where I had it filled thinking something was wrong with the valve. I explained the situation and they guy tells me because of the heat (it was near 80 yesterday - prolly close to 100 in the truck) the safety valve gave emptying the tank. He tells me I'm lucky I wasn't in the truck when it happened.

Anyhow, just thought I'd pass that info along...

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My garage can hit 100

doug293cz said:

Tank must have been overfilled, or had a defective blowout disk. According to the chart in post #96, a properly filled tank should not have its pressure relief disc blow out at less than about 130°F.

Brew on

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I agree with this conclusion. I haven't ever had an issue, but I live in South LA and after they fill my CO2 tank they keep it outside in a open-walled warehouse until I can pick it up. Louisiana summers are relentless and they still don't have any issues. I'm thinking it was either over-filled or a faulty tank/relief device.

I also agree with another person in taking to avoid Welding supply shops. I used to use one and they let me watch the guy fill it. Let me tell you, there was no science or measuring there. He stopped filling when he thought it was right. Now, I use an industrial gas supply company and they seem to have all the safe guards in place.

Clearly the bottle was overfilled. If you just take a CO2 bottle into a fill station and hook it up to a siphon you are not going to overfill it, especially if you have just taken it out of a warm car, and it isn't going to rupture the safety disk at 100 °F. The shops that fill bottles this way take advantage of he fact that they can fill your 5 lb bottle with 3.5 or 4 lbs of CO2 and you are happy with it. If you are watching them do it you hear the flow and then it stops so it must be full, right?. But it stops well short of 5 lbs. The proper way to do it is put it on scale and pump in the liquid until the scale reads 5 lbs over the tare marking and then shut off the pump. That's how the gas suppliers do it.

There are techniques that someone with just a siphon bottle can use to get a full fill but I'm not going to go into what those are because it is easy, unless you use a scale, to get an over fill. I've done it and, as has been noted, the results are very impressive (and I did it with a 2.5 lb bottle).

As for taking a CO2 cylinder into the vehicle cab: don't do it. I've had a 50 lb siphon start to leak from a faulty valve on the way out of the gas supplier's parking lot on a cold day. It was in the bed of the truck, fortunately. Of course I'm not sure I could get a 50 lb siphon bottle into the cab of my truck but I wouldn't try to.

I had a full 20 lb tank empty itself in my garage a few weeks ago. I was in my house when the rupture disk blew - I figured out pretty quickly what it was.

I opened the door to pull the tank out (it was still venting) and put it outside. I got short of breath pretty quickly even with the doors wide open. I saw that when I moved the tank earlier in the day, I moved it to a spot where it sat in the afternoon sun. I guess that temp change was enough to rupture the disk. I'm still surprised that it was enough - it wasn't THAT hot in the garage.

How many of you are watching the dates on your tanks and doing proper maintenance? We used CO2 at the casino where I worked to clean dirt and debris off slot machine circuit boards. The tanks we used were re-certified every 5 years to make sure they were safe and the safeties replaced at that time. We used the same tanks the bar did so it was beer grade CO2. It was dry and free of contaminants and that is why we used it to clean off the casino scum(casino scum is a mix of human hair, skin, barf, other bodily fluids and do not ask! along with coin and paper dust, food residue...) it was nasty stuff and we wore respirators when we cleaned the slot machines once a month.

MaryB said:

How many of you are watching the dates on your tanks and doing proper maintenance?

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The place I take my tanks to be refilled checks the dates every time. I like to think they're just being safety-conscious, but part of me also knows they're looking for an opportunity to upsell me to a recertification, which they also do.

I trade my tanks in, so the hydro date only matters if I get one that's expired and of course I ask for another cylinder.

Early on in my brewing experience I and my son went to get a refill of a 5 lb. cylinder. Popped open the hatchback, started home. Tank was propped up a bit on a blanket--started home and the tank rolled, opened the valve. Instantly the car was filled with a cloud of CO2--could not see a thing. Thankfully we got to side of road, and stopped to clear the air. Don't do that.

Was it in direct sunlight?