Oxygen Use: Cast or Wrought Copper ?

Or by type : Type K, L, M ... ?

You must take precautions to exclude any organic material, oils, etc. (even residual manufacturing lubricant) when installing oxygen systems. For this reason, you must purchase specially cleaned and capped tubing and use careful installation procedures.
http://www.copper.org/publications/pub_list/pdf/copper_tube_handbook.pdf starting on page 14 is a good reference.

The oxygen supplier will have advice immediately to hand. Make the call.

Making a wrong decision here could kill someone.

You are obviously not qualified to make a decision like this.

You obviously don't even have the skills to search for the answer.

Material Guidelines for Gaseous Oxygen Service (PDF) - Emerson

This is but one of many guides available if you look. Still, I stand behind my opinion that you are not qualified to perform material selection for oxygen service.

Thanks for the link Lyn. I didn't ask for your opinion on anything else. You are obviously not qualified to be likeable.

That's all you get here, is opinions. If you want facts, you'll have to do the work yourself.

Personally I would not choose copper for use in O2 service, it will corrode pretty rapidly.
A standard seamless stainless steel instrumentation tubing would be far more preferable, from a chemicals perspective, and an easily maintained jointing system.
Don't re-invent the wheel. :)

Going back to your original question, I doubt that there is a manufacturer out there of "cast" copper tubing. Copper is a bear to cast and as far as a thin wall tubing probably impossible. Most cast copper is used in electrical applications such as parts for welding machines, electrical contacts, etc. Even the fittings used on copper tubing are generally made from a yellow brass and not copper. Copper is generally too soft for threading to be effective and through bolts and nuts are utilized. Which is why I would be doubtful that cast copper elbow, couplings etc would be effective and therefore not be commercially available.

Copper is used for Oxygen for medical gas it comes med gas rated cap and seal the fittings also come sealed. There are miles of copper oxygen lines in hospitals all over the world. I have also seen copper used for oxygen for other applications its typically brazed/silflossed with a low pressure nitrogen purge to prevent oxidation (NPI ) inside the pipe at the joint.