Vintage cylinder questions

[sealark]

With that bushing in the tank I doubt it was manufactured as a Dive cylinder. 1/2" NPT was the first valve sizes for USD tanks. I would not use that tank for diving for fear of that brass bushing failing. Or at best never fill it above 1800 PSI. You could get it hydroed for the stamped pressure but the valve and bushing must be removed when it gets hydroed.

 

[captain]

If it is a solid brass bushing and not damaged upon removal it is fine, after all, all valves are brass.

 

[ofg-1]

Replace the bushing. Get one that is clearly identified for high pressure. I use Cajon fittings, but there are others.

The worst tank accident I have seen was many years ago, a friend had filled one of these tanks, went to take it out of the fill tank, and the bushing came out of it. He lost a eardrum, broke his arm and wrist, and propelled the valve through the ceiling. He was lucky he was not directly over it. The owner had bought a hardware store bushing.

I have a pair of double 38's that I still fool around with, but, first thing I did was replace the bushings when I got the tanks hydro tested.

 

[captain]

3000 psi brass bushing

McMaster-Carr

 

[george_austin]

You guys continually confound me with your knowledge - I just got a nice set of 1800# 38's but I was a little more fortunate as they are DOT and have the 15/16 inch inlets for the common 3/4 inch straight manifold threads