CO2......

Are there different grades of it, (food grade, industrial grade, etc…)?
I know that some types of fire extinguishers are charged with it, and a Buddy of mine uses straight CO2 as the shielding gas for his Mig welding operations…

Any differences in them, and the pitfalls of not selecting the proper one?

Thank you much!

No difference.

I fill my tank at 2 different fire extinguisher shops. They both know I use the tank for beer. 1 was a home brewer years ago.

I also have some 9oz paint ball tanks I use if I take a keg on the road. The PB shop I have it filled at is owned by a guy that works for a big ethanol company. He know what I use the tanks for.

If a major supplier (air gas, linweld…) tells you other wise, find a new shop.

I’ve found the fire extinguisher shops are less expensive and usually fill on the spot. If you can leave the tank they will appreciate it. They waste more CO2 purging their lines than what they use to fill a 5lb tank. So if they can fill yours when they fill other tanks it saves them time/gas.

Yeah, I just exchange mine at AirGas. The 5-20# bottles are filled from the same tank as the 50#.

Thanks all!