Medical O2 tanks have a slightly different thread designation from the old 1/2" straight pipe thread Healthways used for a year or two. The Healthways era predates the current DIN valves by several decades. I'd have to compare the actual specification dimensions on both to determine if they do in fact inrerrchange. Be aware that CGA has historically and intentianally NOT used the same threads as are standard on SCUBA rated bottles for O2 for safety reasoons. This makes it hard to put O2 into a bottle that has been used for SCUBA and may have some oil contamination, thus eliminating the rapidly expanding orange ball at the O2 fill bench. For that reason alone I expect the threads are not the same. Memory places the CGA-870 thread as a 7/8-14UNF, slightly larger than the 1/2" straight pipe (.840 dia) should be, but my CRS says not to trust that number until I can check it.
I have the specs for the current CGA-870 valve straight thread at home, but probably won't be back there until this weekend.
A "standard" DIN valve could be cut down with the aid of a 4 jaw chuck and good threading lathe, or a good CNC mill and thread milling equipment but unless you have the tooling and time to do the job yourself the $s to do that will on a onesy twosey basis will be larger than the $s necessary to buy a similar sized tank with the "correct" thread for a DIN.
FT
