Scuba Bottle for CO2

[Surface_Tension]

I was noticing that CO2 tanks are aluminum cylinders rated for 1800 psi.

I have a gaggle of 80 cf scuba tanks which are aluminum cylinders rated for 3000.

If I put the appropriate valve on a scuba cylinder shouldn't it work for a CO2 bottle? I wonder if the thread in the neck are the same?

I guess this is probably a question for my local gas supplier. And I suppose by the time I get the right valve I could have bought a standard CO2 bottle. I was just wondering if anybody here is gone that route.

Dave

 

[DrugCoder]

I checked into this myself a month or so ago. Talking with a buddy that runs a SCUBA shop he said basically the same thing you came up with. First you would have to change out the valve and then you would also have to have it re-certified before anyone would fill it. Both of those together would put you close to the cost of a CO2 bottle. Even worse for me since I don't already have the SCUBA tank...

 

[wreals]

Why would you need to re certify the tank if you changed the valve? The hydro test that is done on all cylinders is done without the valve. All a filler looks for is a DOT approved hydro stamp in most cases. Hydro stamps are good for 5 years per tank, the valve is not tested at all.

I'd try to find a valve for it buy the valve could costs as much as a dedicated CO2 tank that you could find on Craigslist

 

[DrugCoder]

I don't know for sure that it would have to be retested. I was just going off what my SCUBA buddy said assuming he knew what he was talking about. I figured they did the testing with the valve as well so it would go through the test also.

 

[JuanMoore]

I don't know for sure that it would have to be retested. I was just going off what my SCUBA buddy said assuming he knew what he was talking about. I figured they did the testing with the valve as well so it would go through the test also.

The valves have burst discs to safely vent the gas should the pressure in the tank become too great (like if you leave it in a hot car). The tanks are tested for 5/3 of the pressure rating, and the burst discs are of course set to blow at or below the pressure rating, so the valve needs to be taken off prior to testing, and re-installed after.

 

[Surface_Tension]

I'd try to find a valve for it buy the valve could costs as much as a dedicated CO2 tank that you could find on Craigslist

That is kind of what I was thinking too. I'll probably stop by the gas supplier and see what they say. I need to figure out what kind of valve it is and I'm concerned that the threads might be different too. I'm a do it yourself person at heart but sometimes I've learned that it just easier to spend the money up front! LOL

The hydro is a DOT required test that has to be done very five years as mentioned. They take the valve off the tank, fill it with water, put it in another vessel of water which has a pito tube on it, and then pump the vessel being tested up to 5/3 its rated pressure. Then by the reading on the pito tube they can measure how much the tank expands and then contracts. There are criteria it must be within for it to pass.

I would imagine those of you who have CO2 tanks are having to have this done.

Thanks.

Dave

 

[DrugCoder]

That makes sense. Now I know how the testing is done. Thanks for the info!

 

[broadbill]

My CO2 tank started its life as an medical oxygen tank. Its a different shape and rated to 4000psi. It was purchased from Adventures in Homebrewing. I can find you the name of the guy I emailed since I had some questions about it awhile back...let me know. I also know they have since moved to the standard Aluminum tanks for their kegging setups.

Hope this helps.

 

[Surface_Tension]

That answers the neck thread question. The valves for CO2 should pretty much be standard no matter what bottle it is on. I guess I figure out what kind of valve I will need and keep my eyes peeled on ebay. I'm also going to check with my local cabonics supplier to make sure they will even fill them.

Thanks!