Tank identity and nitrox question

[Leo53214]

Just aquired my first doubles- steel 72's- one US Diver and one PST (Hydros in 2/09).

Questions:

I cant find crown marking descriptions for old discontinued tanks anywhere.
Any leads?

It has US Diver solid bar. Any benifit to using/upgrading?

What about Nitrox with these guys?

~Curious

 

[cwkline]

Photos would help. I have several 72's, and use them for most of my diving now. You can use them with nitrox, but might need to O2 clean if partial pressure blending. Is the manifold a single outlet? You can use that for practice and learning, but would probably want an isolator eventually.
There are more experienced folks here in regards to older tanks, and hopefully they will ring in with more info for you.
Enjoy the new doubles.
Charlie

 

[Thalassamania]

The tanks are fine, EAN is fine with them, if partial pressure blended they need to be cleaned.

The manifold leaves a lot to be desired. There are arguments about the best thing to do, isolation manifold or independent doubles ... but both camps would agree that what you've got is not the best manifold choice.

 

[halocline]

That manifold, if it's the center outlet, is used for double hose reg diving, so if you want to sell it and buy a modern isolation manifold you'll find some interest in the vintage dive crowd. Does it have a j valve? If so, do you have vintage bands as well with the bracket for the j valve rod? You'll definitely find takers for that stuff.

Piranha has bands for those tanks for about $70.

 

[rstofer]

For partial pressure blending (and you should assume that this will be the case), the manifold will also have to be O2 cleaned. May as well have it serviced...

Check around on eBay and you will see that your manifold has serious value. Unless you plan to use double hose regulators, a center outlet is probably NOT what you want.

If you change to a modern manifold, you may need to change bands as well.

Richard

 

[Leo53214]

Thanks for all the information guys- I am just learning about doubles and every bit of information helps. The straight manifold does not have a j valve or rod, but the bands are original. I think from what I'm learning I would prefer a modern isolation manifold. My LDS recommends 300, but he is a tech instructor and "everyone else" is telling me a 200 is just fine. So now, the next big question. How do I figure out my thread size, etc for valve compatability on the old 72 steels?

 

[Gilldiver]

The threads are either 1/2" pipe or 3/4" "Scuba". If the connection looks like a newer Scuba valve, it is 3/4".

The tanks are only rated up to 2250 psi so a 200 bar manifold is more then enough. I would only go with a 300 BAR manifold if I thought that I would eventualy break down the set into singles and use high pressure tanks (3500 psi). If you plan to break them up and go with low pressure tanks (3000 psi or less), the 200 Bar manifolds are also the right choice.

The alternative is a sherwood twin manifold that will give you 2 posts, one in the middle and one on the right tank. This is a sweet manifold, but you do not have isolation capability. If you go with a sherwood manifold, you will most likely be able to re-use the bands you have right now.

 

[Scared Silly]

The 200 versus 300 bar has nothing to do with the actual usage pressures. It is simply a descriptor for the valve connection. In fact structurally, there is absolutely no difference between a 200 and 300 bar manifold except literally a couple of threads.

This is one of the best explanations out there:

http://www.divegearexpress.com/library/valves.shtml