Vintage Double Hose

Most of my experience with USD manifolds has been with older vintage sets that for some strange reason used the standard Oxygen connections, CGA-540. At some point in time they changed to the standard and more appropriate Air connections, CGA-346.

I'm not sure when that occurred, and only noticed a couple of years ago that i had some of each. Anyone know when that change took place?
Newer valve on the left is CGA-346 connection, the compressed gas industry standard for AIR.

I was wondering about this CGA-540 thread issue a few months ago. My son gave me a nice oxygen tank and I tried putting a USD center section on it. It seemed to fit fine and I was wondering if anybody ever made up doubles that way. This manifold center section looks fairly new.

I have never come across the air connection manifold, didn't know it even existed until today.

SurfLung wrote: ↑

Wed Feb 14, 2018 10:38 am

I was wondering about this CGA-540 thread issue a few months ago. My son gave me a nice oxygen tank and I tried putting a USD center section on it. It seemed to fit fine and I was wondering if anybody ever made up doubles that way. This manifold center section looks fairly new.
CGA540.JPG

Plug the gauge outlet and that would work for a set of mini-doubles!

captain wrote: ↑

Wed Feb 14, 2018 11:01 am

I have never come across the air connection manifold, didn't know it even existed until today.

I was surprised too.

I wonder if any other SCUBA manufacturers used the Oxygen-type fittings on their manifolds?

I would like to hear from anyone about the CGA nut and nipple connections on other brands of manifolds they have.