need some advice setting up doubles

[aquaoren]

There are two different 'standard' tank orifices. 0.750-14 NPS, or "3/4" and 0.875-16 UNF, or "7/8". Aluminum tanks are 3/4, as are low and the new 'mid' pressure E8 series steel tanks. High pressure [3500 psi] steel tanks are mostly 7/8.

So a manifold for your aluminum would work on a 3/4 threaded steel tank. If you go that route, you probably will want to get a 300 BAR manifold as opposed to a 200 BAR manifold.

One thing to note since I'm on the topic. The "3/4" and "7/8" is referring to the .750 and .875 in the thread naming. It does 'not' imply 3/4" and 7/8"; in fact, the 7/8 is a smaller opening then the 3/4. So if all you remember is "3500 psi tanks have a smaller opening", you'll end up buying the wrong manifold.

These are only the 2 North American standards for neck threads. Don't forget the European M25x2 neck threads.
The tanks in Brunei don't have to have North American standards.

 

[Freeflyer]

These are only the 2 North American standards for neck threads. Don't forget the European M25x2 neck threads.
The tanks in Brunei don't have to have North American standards.

That's true, for reference my tanks are Catalina Al80's. Funnily enough, I've just found I'm moving back to the UK for a year or so, although I won't be able to bring the dive gear back for a few months yet. Damn, I might have to buy a dry suit. Brrrrrrr.

Thoroughly spoiled from being in warm clear water for a while.

J.