Q) 1/2 valves?

[Hoosier]

I got two old steel 50 tanks including 1/2 straight pipe threaded valves (I think).

Please check out the pictures below.

Question)
1. Is there any 1/2" DIN valves out there?
2. If there are 1/2" DIN valve, where can I get those valves? eBay?
3. Does O2 medical valves also use the same 1/2" size thread?


I plan to use these steel tanks for O2 emergency tanks ONLY on the ground. The tanks inside are clean even though I need to do O2 cleaning by myself.

Thanks for your expertise in advance,

 

[DA Aquamaster]

1/2" NPT threaded valves are hard to fine, but you could check the vintage scuba sites. I am not aware of any DIN variants.

Current O2 bottles use a 1/2 valve with a teflon seating ring and are not sealed with teflon tape The tank is milled with a reces for the ring so the valves are not interchageable.

 

[oxyhacker]

Not necessarily. Small steel medical 02 tanks, like Linde's (who apparently won't put O2 in aluminum) still use 1/2" taper thread valves.

I can't recall ever seeing a 1/2" DIN valve, though.

Current O2 bottles use a 1/2 valve with a teflon seating ring and are not sealed with teflon tape The tank is milled with a reces for the ring so the valves are not interchageable.

 

[pescador775]

That particular 1/2 inch valve is difficult to remove without damage. Also, they appear to have been installed with pipe dope, nasty stuff. The NPT valves in 1/2 inch size show up on EBay frequently. Your main problem will be removing the old valves but it can be done. The tank should be secured in a chain vise (pipe vise) and the valve removed with proper size wrench (big).
Pesky

 

[Luis H]

The DIN valves in the picture below look like they are 1/2" NPT, but they are not. They are a metric thread that is just a bit smaller than the 1/2" NPT and of course a different thread pitch.

Each tank valve is a DIN valve and the manifold has two male DIN connections.

If you run into valves like this be careful and don't get them confused, they will not fit.

I had an adapter made from this size to a female 1/2" NPT so I could have the tanks hydro tested.

Finding 1/2" NPT oxygen valves shouldn't be hard.

 

[Hoosier]

Thanks all..

So, is a toggle valve on the medical AL tank also a 1/2" thread?


I could screw out the valves with an adjustable wrench and rubber hammer (slight forces). I don't think it is a big deal. I hope that 1/2" thread is string enough for that.


It looks like I can get a rebuild kit from NESS, but a kit only includes one O-rings and two washers. In addition, I am not sure mine is Sherwood brand.


Do you think which valve is safer to use between a toggle and rebuilt 1/2" valve?

 

[Luis H]

To remove them make sure the wrench sit across the front of the valve (never gripping it on the sides). The wrench on the sides will roll the edge of the valve ruining the O-ring connection edge. The wrench across the front will mark the face but will not affect the yoke connection interface.

 

[Luis H]

Thanks all..


I could screw out the valves with an adjustable wrench and rubber hammer (slight forces). I don't think it is a big deal. I hope that 1/2" thread is string enough for that.

A big adjustable wrench with a cheater pipe if needed is OK.
I would not recommend a rubber hammer. Impact loading doesn't work well with a tapered thread. What you need is a constant steady load.
It is not like you have to break it loose. You have to turn it loose. It takes some rotation before it actually loosens up.

 

[Hoosier]

OMG.. I already used a rubber mallet and a wrench sat the side... I hope I woludn't ruin the valve yet.

I don't fill the tank yet to clean it out as soon as I find out a valve option.

I should have asked/posted before doing something...

Another newbie mistake....

 

[Zieg]

Let me check, I may have a couple of new 1/2 valves packed away in a box somewhere. I'll check tomorrow and see if I can find them.