[flbrewer]

Ok after scouring the Internet (bless my sales job without an office) I've come to the same conclusion. Cintas fire folks mentioned they fill for Pepsi locally, good enough.

[kramerog]

Food grade tanks are properly purged by the dealer and then refilled.  Welding grade tanks are typically refilled without purging.  The carbon dioxide going into the tanks is the same, but what comes out could be different because of the differing purge procedures.  I use welding gas grade.

[flbrewer]

^ I didn't read this, but I did read the only real factor is the tank. Paintball tank? Probably an issue. 

[narcout]

So do tanks get contaminated over time?  One more thing to obsess about.......

They need hydrostatic testing every so often (what is it, every 7 or 10 years?).  If you are swapping out tanks at a gas services company, it shouldn't be an issue.

Not as likely if you have check valve installed- preventing back flow of beer in regulator and tank.

You definitely want to make sure you have the proper check valves in your system.

[hopfenundmalz]

So do tanks get contaminated over time?  One more thing to obsess about.......

They need hydrostatic testing every so often (what is it, every 7 or 10 years?).  If you are swapping out tanks at a gas services company, it shouldn't be an issue.

Not as likely if you have check valve installed- preventing back flow of beer in regulator and tank.

You definitely want to make sure you have the proper check valves in your system.

Certified by a hydro test every 5 years.

[majorvices]

I did not read the whole thread so forgive me if I missed anything but there is a difference between industrial Co2, food grade co2 and even beverage co2. I think the most important difference is that they rank in expense in the order I listed! Whether there are any other differences I am not really sure but supposedly the other co2s are not as pure and have some o2 present in varying degrees.

[erockrph]

I did not read the whole thread so forgive me if I missed anything but there is a difference between industrial Co2, food grade co2 and even beverage co2. I think the most important difference is that they rank in expense in the order I listed! Whether there are any other differences I am not really sure but supposedly the other co2s are not as pure and have some o2 present in varying degrees.

I've heard something similar as well. I think what I've read is that Industrial is 99% pure, Food-grade is 99.9% and Medical grade is 99.99%. And that comes from the internet, so you know it must be true... 

[Wort-H.O.G.]

I did not read the whole thread so forgive me if I missed anything but there is a difference between industrial Co2, food grade co2 and even beverage co2. I think the most important difference is that they rank in expense in the order I listed! Whether there are any other differences I am not really sure but supposedly the other co2s are not as pure and have some o2 present in varying degrees.

I've heard something similar as well. I think what I've read is that Industrial is 99% pure, Food-grade is 99.9% and Medical grade is 99.99%. And that comes from the internet, so you know it must be true... 

so in essence, most of us are pumping 1% O2 into our beer...must not be an issue?

[flbrewer]

^so I can stop aerating? I joke. I think the concern (if it exists) is Benzene and some other nasties.

[erockrph]

I did not read the whole thread so forgive me if I missed anything but there is a difference between industrial Co2, food grade co2 and even beverage co2. I think the most important difference is that they rank in expense in the order I listed! Whether there are any other differences I am not really sure but supposedly the other co2s are not as pure and have some o2 present in varying degrees.

I've heard something similar as well. I think what I've read is that Industrial is 99% pure, Food-grade is 99.9% and Medical grade is 99.99%. And that comes from the internet, so you know it must be true... 

so in essence, most of us are pumping 1% O2 into our beer...must not be an issue?

Well, you could be putting as much as 1% of "other stuff" in there, if these reports are to be believed. Could be nitrogen, water vapor, oxygen, acetylene, etc. I'm not too concerned, frankly.

[majorvices]

I'm telling you only what I heard from the co2 guys. There's also the guys who said "they pull it a from the same tank" so there's that. Regardless, I wouldn't worry too much about it for homebrewed beers.

[S. cerevisiae]

Ok after scouring the Internet (bless my sales job without an office) I've come to the same conclusion. Cintas fire folks mentioned they fill for Pepsi locally, good enough.

I switched to using fire extinguisher service CO₂ after my first year of kegging, and have never looked back.  I am still breathing over twenty years later; therefore, it is safe to assume that the 1% that is not CO₂ is not carcinogenic. 

[Thirsty_Monk]

I'm telling you only what I heard from the co2 guys. There's also the guys who said "they pull it a from the same tank" so there's that. Regardless, I wouldn't worry too much about it for homebrewed beers.

And my supplier name is .... Welding and gas. Bring CO2 on big truck and fill my 600lb tank.

Now when we are talking about O2 and CO2. There is O2 in CO2 I think.

[flbrewer]

Ok ladies and gents....so after scouring the inter web and filling my shiny new CO2 tank today at a local Cintas, I had a nice conversation with a tech. He told me that they get their CO2 from Airgas, which confirmed they supply food grade CO2.

The Cintas guy went on to say he's only heard of impurities as an issue related to the tank quality of the supplier. A rusty tank may lead to impurities and other things going into the end user's tank.