I wouldnt use copper, there is a flexible yet "rigid" plastic tubing available in most home centers in the plumbing section that will work well and be safer and will easily connect to the soft tubing for end points.

 

Interesting. I remember reading that copper is the way to go on long runs. The copper is stronger and will not permit any of the CO2 to escape or permeate out into the atmosphere.

I agree a plastic tubing would be much easier to attach to the regulator or other fittings.

I am not certain the CO2 is going to react with the copper, or how it would react with the copper if it did.

Mike

 

I would guess the copper would be fine. No CO2 loss, cheap. As long as there is no H2O in the gas (there wont be) the CO2 won't react with the copper.

Of course, all just conjecture on my part!

Aint it great to get so many different answers?

 

It might be best to just run the flexible tubing through a copper sleeve instead. Labs use copper piping for pressurized CO2 and other gases, but then use silicon tubing to CO2 incubators or cell culture vessels. It can be done.

Dang! Where's everybody on Mondays?

 

Copper tubing is standard issue for permanent CO2 installations - there's many kilometres worth underneath the world's soda fountains and pubs. You have to be careful not to kink it during the install, but once it's in place it won't collapse under its own weight, harden and crack, or leak CO2 through its walls like a lot of plastics will.

Any cats or small rodents in your crawl space? Copper is less likely to be be chewed - it tastes terrible.

Copper is inert as far as CO2 is concerned, and is resistant to carbonic acid (formed when CO2 hits water), but you should still have a check valve plumbed in to prevent water from entering the piping and your CO2 cylinder just in case you don't notice when your cylinder runs out of gas. This is true for plastic as well, since the last thing you want inside a steel high pressure cylinder is a mild acid soup.


Keep the copper out of direct contact with your tank water and there will be no toxicity issue.

I'd provide references for the above information, but it's Sunday morning, I don't feel like looking them up, and this is the Internet, after all. What's Latin for "Reader Beware"?

 

Thanks Bonsai. That seemed obvious about the soda machines as soon as I read it.
That is what I will do. roud:

 

And you can just terminate the copper with standard compression fittings.