Doubles manifold question...

[DC53]

When assembling my doubles, if both tank bands are bolted tight and the manifold is screwed in to the point where it is neither pulling the tops of the tanks together nor pushing them apart, there is more than 1/8" of manifold threads showing... With a caliper I measure it at about 0.16" or somewhere between 1/8" and 3/16".

If I try to keep it at 1/8" like the instructions with the bands says, the manifold needs to pull the tank valves together with what I would estimate, given the fine threads on the manifold, as a substantial tension. Should I leave more threads showing to the degree noted (about 0.160 inch), and relieve this pressure or would that in some way interfere with the o-ring seals? I do need to take them apart periodically when I need big single tanks.

Worthington steel HP 120's, Dive Rite bands, Sea Elite 200 bar manifold.

Thanks for input!

 

[battles2a5]

You have the right idea. I usually assemble them loosely, slip the bands on, then gradually tighten things down making sure that nothing is binding anywhere and that there is no exess pressure on the bands or manifold. It doesn't need to be exactly 1/8", you're not going to hurt anything.

 

[elan]

When assembling my doubles, if both tank bands are bolted tight and the manifold is screwed in to the point where it is neither pulling the tops of the tanks together nor pushing them apart, there is more than 1/8" of manifold threads showing... With a caliper I measure it at about 0.16" or somewhere between 1/8" and 3/16".

If I try to keep it at 1/8" like the instructions with the bands says, the manifold needs to pull the tank valves together with what I would estimate, given the fine threads on the manifold, as a substantial tension. Should I leave more threads showing to the degree noted (about 0.160 inch), and relieve this pressure or would that in some way interfere with the o-ring seals? I do need to take them apart periodically when I need big single tanks.

Worthington steel HP 120's, Dive Rite bands, Sea Elite 200 bar manifold.

Thanks for input!

You have a barrel type manifold with 2 o-rings ? not the face ring one with one o-ring ? If you have barrel type it is not a big difference if you have 3-4 or 5 threads, it is still enough. The bands should hold the tanks, the isolator should not be tensioned and it should rotate easy, this means the isolator is aligned well. If it rotates with the substantial amount of force it means it is either misaligned or screwed too tight

 

[DA Aquamaster]

You have the right idea. I usually assemble them loosely, slip the bands on, then gradually tighten things down making sure that nothing is binding anywhere and that there is no exess pressure on the bands or manifold. It doesn't need to be exactly 1/8", you're not going to hurt anything.

I'd just add to this the suggestion to assemble them lying on a flat surface so the tanks stay square and parallel to each other as the bands are tightened.

Tighten the upper and lower bands equally a couple turns and then test the isolator to ensure it moves freely. If it starts to bind you'll be able to feel what direction it needs to rotate to loosen up slightly.

 

[DC53]

You have a barrel type manifold with 2 o-rings ? not the face ring one with one o-ring ? If you have barrel type it is not a big difference if you have 3-4 or 5 threads, it is still enough. The bands should hold the tanks, the isolator should not be tensioned and it should rotate easy, this means the isolator is aligned well. If it rotates with the substantial amount of force it means it is either misaligned or screwed too tight

Yup, barrel with 2 o-rings. I can kinda see that the o-rings are pretty well into the smooth part of the barrel and assuming it's not conical to some degree which I doubt then it should seal but I figured I'd ask as I am forging into new territory here.