I use paintball CO2 cylinders to carbonate water. Basically a modified SodaStream set up to save money. Instead of paying SodaStream $14 for a proprietary cylinder, I have paintball cylinders filled for $3.
When I had my 3 cylinders filled recently, one of them felt heavier than usual. The guy also had some difficulties filling one, and I assume it was the one that felt heavier. Maybe it wasn’t heavier, and I just thought it was.
At home in the kitchen the cylinder started venting CO2. It was loud and scary. My gf came running. I grabbed it with a towel and ran it outside, where it continued discharging CO2 until it was empty. Curious, I touched the cylinder and it was cold enough to burn me.
This was it on my porch.
Some research told me that the CO2 discharged via a burst disc (?) which I removed easily.
So…What happened and why? Can the burst disc be replaced with a new one, or is that a no-no? What can I do to prevent this happening again? Is there a risk to suddenly venting 20 ounces of CO2 into an indoor environment?
Sounds as if it was overloaded, probably due to a problem with the fill regulator. The purpose of the burst disc is to prevent the bottle from being overpressurized and it would seem to have done its job. I don’t know what the burst margin is on those cylinders but they are so lightweight and at such low pressure (~850 psi max at standard temperature) that even if it did rupture there probably isn’t a big personnel hazard unless you put it in the middle of a bunch of glassware. The ‘hazard’ from the ~35 liters of CO2 unless you are in an airplane lavatory. If you start to feel drowsy or a headache coming on open a window.
CO2 is not poison, and it’s everywhere in the air already. If it’s causing you problems, you will know. You will feel like you’re suffocating and need air.
So don’t ignore the feeling of suffocating and needing air.
Unlike, say, nitrogen asphyxiation, where you just pass out without noticing anything is wrong.
That said, I don’t know if you were asleep that the discomfort of elevated CO2 would wake you.
I think it would. I’ve seen hamsters killed by CO2 suffocation (it was in a lab, and i don’t remember why they decided to kill them that way.) It was pretty horrible, and the hamsters were clearly aware they were being suffocated.
I buy carbonated water and drink about one a day just for the “bubbly”. After hearing this story, I think I’ll stick with paying for it from a store. Shoot, if that canister had exploded, it could have really been bad.
I think the purpose of the burst disc is to avoid the cylinder rupturing.
Heh. Brand new regulator, and the guy had to figure out how to use it. The other gas place I’ve gone charged me $11 a cylinder. The place closer to me used to charge $3 a fill, but their regulator setup for small tanks broke.
The guy didn’t want to replace his since it was a small profit thing, so I bought my own ($40) figuring I’d make it up quickly.
Yeah, that would really add up in a hurry! I can see the need over time.
I didn’t know those canisters had a “fail safe” function designed to prevent a detonation. Still, should you have picked it up and carried it outside? I suggest just leaving immediately. You could always open the windows and air the place out once the pressure is relieved.
Well, “all’s well that ends well” - this time! Still, I don’t understand the malfunction. If the process was defective, shouldn’t ALL the cylinders suffered the same fate? Why just one? I ask because I think it is important to identify the cause, otherwise it may happen again.
If your blow off cap ruptures, your CO2 will vent from the bottle and you will have to replace the cap and refill your bottle. Check with your gas supplier first to see if they have one of these in stock (most of them do). Otherwise, purchase one of these from us and have them install it. A certified gas technician needs to replace this cap, otherwise you will void your warranty.
Your gas guy probably qualifies as a certified tech, or he could know someone.
You’ve already identified the primary clue. The tank was heavier that expected. Now you know what it means, so just vent the excess gas. Back when we had a paintball field the gas fill station would shut off when the tank reached a predetermined weight. You can get a hanging scale from Walmart or Amazon to double check your tanks yourself.
This, the grading is probably not in the actual gas, but in the level of allowable oils and contaminants from the compressor, connectors and canisters that are allowed for paintball guns vs human consumption.
I worked in the compressed gas industry for over a decade.
The burst disc worked exactly as advertised. There are no fragments to speak of when these rupture and they are definitely replaceable.
CO2 is filled by weight, and your tank should have a tare weight and allowable fill weight so it should be easy to weigh and see if a tank was over filled (as your certainly was). All compressed gas tanks must be hydrostatically tested every 5 or 10 years. Date of last test will be stamped in the cylinder shoulder
The only difference between medical grade CO2 and commercial grade is the batch traceability required for medical gases.
