C02 Tank Identification Help

I received an old C02 tank recently and I was wondering if someone out there could possibly help me with some questions I have about this tank.

Here are the facts:

• The rough physical dimensions are 31-inches tall (not counting the tank valve) by 7-inches diameter.
• It's at least 25-years old. Maybe even 30-years old.
• I think it's made of steel.
• I took it to the local welding shop for re-certification inspection last week, they in turn sent it to another agency, and it passed.
• The guy at the welding shop said he had never seen a tank like this used for beverage dispensing before.
• I know it was used for beverage dispensing for many years prior to me obtaining it.
• The welding shop guy said they weren't sure of the total capacity of the tank so they only filled it with 20-pounds of C02. (maybe they just didn't have the time to research it?)

My questions are:

1. Is it safe to use this tank for beverage dispensing?
2. What is the total C02 gas capacity of this tank?

Any information would be appreciated!

Lacking the time to properly research my statement before I fly out the door tonight, I provide this link:
http://www.catalinacylinders.com/co2.html
Where tank B15 is approximately 7" in diameter and 23" tall, it holds 15 lbs. So if you extrapolate that to your tanks dimensions.. I get 20.2 lbs. Feel free to double check my math.

I'm out the door, let the arguing commence! ;-)

Bump

You should be fine serving beverages out of this tank. Don't know the full tank capacity.

If you're worried, just find a shop that swaps out tanks and see what they swap it out for! You'll probably get a nicer 20# tank in exchange and then don't have to worry about this one anymore.

There should be a stamping near the top of the tank which indicates the capacity. A 20 lb cylinder will be marked like this: 20 CO2

This stamping will usually be immediately adjacent to the DOT numbers. IMO, it is foolish and dangerous to fill a cylinder without knowing the capacity beforehand. Guessing at the capacity doesn't cut it.

Bulk compressed gas cylinders such as these are required by federal law to have stamped identification numbers which include a serial number, hydrostatic test date, tare weight and capacity. There should be no need to guess at anything. I may not have all of this exactly right, but it should be fairly close.

Ace_Club said:

You should be fine serving beverages out of this tank.

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These are actually referred to as cylinders.
I have a similar CO2 cylinder. A size 10S cylinder 4" x 31" holds 7# of CO2
These can withstand pressures in excess of 2500#
Liquid CO2 will normally create an internal pressure of 700#
ACE_CLUB is correct you are perfectly fine.

It is most likely a 20 or 35 pound cylinder being that it was 20+ years old the welding shop should have sent it out for hydrostatic testing that needs to be done every 5 years.

Catt22 said:

IMO, it is foolish and dangerous to fill a cylinder without knowing the capacity beforehand. Guessing at the capacity doesn't cut it.

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I'd tend to agree with you if he was trying to fill this himself. Rather, he correctly had the tank hydro-tested to ensure safety and then has it filled at a shop. When I bring in my tank for filling, I don't specify how many #'s of CO2 I want in it, they just know to fill it to 10#.

The best bet for him to find the capacity would be to ask the next time he has it filled, if he doesn't figure it out before then.

In the OP, "The welding shop guy said they weren't sure of the total capacity of the tank so they only filled it with 20-pounds of C02. (maybe they just didn't have the time to research it?)"

This tells me that the welding guy doesn't know what he is doing. The fill capacity is always stamped on the cylinder. It sure sounds like he was guessing to me. I've never heard of any customer dictating to the fill station people how much to put in a cylinder. It's just not done that way, ever. Cylinders are filled by weight. It's the only way to be sure how much CO2 is in the tank. That's the purpose of the tare weight stamp.

Catt22 said:

In the OP, "The welding shop guy said they weren't sure of the total capacity of the tank so they only filled it with 20-pounds of C02. (maybe they just didn't have the time to research it?)"

This tells me that the welding guy doesn't know what he is doing. The fill capacity is always stamped on the cylinder. It sure sounds like he was guessing to me. I've never heard of any customer dictating to the fill station people how much to put in a cylinder. It's just not done that way, ever. Cylinders are filled by weight. It's the only way to be sure how much CO2 is in the tank. That's the purpose of the tare weight stamp.

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Yes there is a tare weight or total weight stamped on the collar of the cylinder somewhere usually opposite the DOT-3AA He should not just guess at the total weight b/c if that happened to be a 15lb cylinder you will blow off the safety. Believe me you will know it if it happens. It looks to me like a 35lb.
Do some more research before you fill it again.

LiquidLunch5211 said:

Yes there is a tare weight or total weight stamped on the collar of the cylinder somewhere usually opposite the DOT-3AA He should not just guess at the total weight b/c if that happened to be a 15lb cylinder you will blow off the safety. Believe me you will know it if it happens. It looks to me like a 35lb.
Do some more research before you fill it again.

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FYI, the tare weight (TW) is the weight of the empty cylinder, not the total weight which would be the tare weight plus the weight of the contents. I often weigh my little 5 lb aluminum cylinder in order to determine when it is nearly empty. I marked the full weight (including the regulator and hose) on the side of the tank with a Sharpie. This way I don't need to remove the regulator when checking it.

Catt22 said:

FYI, the tare weight (TW) is the weight of the empty cylinder, not the total weight which would be the tare weight plus the weight of the contents. I often weigh my little 5 lb aluminum cylinder in order to determine when it is nearly empty. I marked the full weight (including the regulator and hose) on the side of the tank with a Sharpie. This way I don't need to remove the regulator when checking it.

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There is a total weight stamped on the collar of the valve sometime on old steel cylinders. There is a flat spot at the base of the valve by the collar and the is a stamped total weight of liquid and cylinder.

they did the right thing putting 20 lbs in it. they said they have not seen them used for beverage use because its a 2015 cylinder. its thicker so its suited for oxygen use or ither non liquid gas.

its an 80 cuft cylinder. my family owns a welding supply shop. if you brought it in to my shop i would have put 20 lbs in it as well. the 35# cylinder in that height would be around 9" in diameter.



also, the tare and full weights as well as the capacity do not have to be marked on the cylinders. the only markings that "have" to be there are serial number, dot number and a test date.

jonp9576 said:

they did the right thing putting 20 lbs in it. they said they have not seen them used for beverage use because its a 2015 cylinder. its thicker so its suited for oxygen use or ither non liquid gas.

its an 80 cuft cylinder. my family owns a welding supply shop. if you brought it in to my shop i would have put 20 lbs in it as well. the 35# cylinder in that height would be around 9" in diameter.



also, the tare and full weights as well as the capacity do not have to be marked on the cylinders. the only markings that "have" to be there are serial number, dot number and a test date.

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I agree with everything jonp9576 has to say. He is obviously the authority on this subject.
My profession is welding and his statements fall in line with everything I have ever experienced dealing with high pressure gas cylnders.
These cylinders are manufactured to hold gas, they just so happen to be suited for liquid gas also.

Thanks for the information everyone. Just trying to understand this cylinder a little better. I may look into swapping it for another cylinder later to get something more current. Not sure if anyone does cylinder swaps around here though.

Thanks again!

Seven,
Why would you want to swap out if it's been stamped recently.
I take mine to a security company that services CO2 extinguishers. It takes them about 10 minutes and I'm out the door.
A fresh paint job would make it look like new again.
These cylinders will last a life time. I've seen some dated back to World War II.

dmfa200 said:

Seven,
Why would you want to swap out if it's been stamped recently.
I take mine to a security company that services CO2 extinguishers. It takes them about 10 minutes and I'm out the door.
A fresh paint job would make it look like new again.
These cylinders will last a life time. I've seen some dated back to World War II.

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My thinking on swapping it for another is to remove any confusion since the welding shop wasn't quite sure what to make of this cylinder. I may swap it at some point in the future but not right now. I just had it hydro-tested and filled with 20-pounds of C02 so I should be good for a while now!

Seven,
How much did they charge you for hydro-static testing that tank ?

Banjoman76 said:

Seven,
How much did they charge you for hydro-static testing that tank ?

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I was pleasantly surprised... they hydro-tested and filled my cylinder for about $50.

Seven said:

I was pleasantly surprised... they hydro-tested and filled my cylinder for about $50.

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Damn! Fifty dollars! I get mine hydro tested and filled for about $24. That was for a 20 lb cylinder not long ago. The charges for both the testing and the gas seem to vary radically from location to location. I guess if you are the only source in an area, you can get away with sky high pricing.

I agree on the pricing varying from store to store. Where I am from it is anywhere from $18 to $36 for the hydro testing, and then filling is about $1 per pound or so. The fill price is about the same everywhere, but the testing....

I was expecting the hydro test and gas fill to cost upwards of $100 so I was happy when they told me it was only $50.

Catt22 said:

Damn! Fifty dollars! I get mine hydro tested and filled for about $24. That was for a 20 lb cylinder not long ago. The charges for both the testing and the gas seem to vary radically from location to location. I guess if you are the only source in an area, you can get away with sky high pricing.

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$24 is really cheap for testing and a fill. where are you from?


i find it interesting to see how geography plays a roll in prices. we sell propane as well, and some of the propane prices people talk about on here are so cheap, and others seem sky high.

jonp9576 said:

$24 is really cheap for testing and a fill. where are you from?


i find it interesting to see how geography plays a roll in prices. we sell propane as well, and some of the propane prices people talk about on here are so cheap, and others seem sky high.

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Cincinnati: Sparkling Carbonics -A good company and they are familiar with home brewers. I will be taking them another 20 lb tank for a hydro and fill this week. I will report back with the current cost soon.

I pay $12 for hydro at a fire safety joint and the turnaround time is 24 hours. I get fills at a beverage distributor for $1 per pound, while you wait.

This was my first foray into C02 cylinder testing/filling so I just took it to the local welding shop and let them do everything. Next time I'll shop around more and maybe I'll try the fire safety businesses mentioned by Bobby_M.

I just got my 20# ca 1951 cylinder hydro'd and filled at a local fire safety shop in Austin, cost me $46, but took four days(!).

This weekend, I gave it a nice new bright red paint job, too. For what it's worth, mine doesn't have a Tare weight either.

Here's the before and after paint job pics...

Damn bro, at a glance being a 3AA bottle it looks to me like a 70 cu/ft
O2 bottle in size of high pressure 2015 psi. It have a +plus after the last hydro date? This allows 10% over fills. At 30 years old is nothing, I own bottles dating back to 1938 that pass as + plus fills. Older thicker than newer steel bottles are all keepers no swapping having the Swatzstikas. I would hang onto it and convert it to a nitrogen gas mix for stouts. I offered $30 and got another Hitler era 150 cu/ft Linde bottle that was restamped over the Swatzstika (must be a PC thing) and still passes as a + plus fills.