Anti-snag valve-down tank mounting?

[CuzzA]

Valve control is pretty important when diving twins with a ceiling as well (deco or solid) when isolating a manifold can be the difference between a thumbed dive and a chamber ride or worse.

I agree, but I don't believe we're talking about doubles in this thread. Single tank, basic recreational diving.

 

[RainPilot]

I agree, but I don't believe we're talking about doubles in this thread. Single tank, basic recreational diving.

Even then the argument could be made that fluttering a tank valve to save gas on a deeper dive with a free flow second stage would be a handy skill, but as it is the OP didn't reference single tank nor has it been specified. In fact, i would argue that since the issue is potential snagging, the most likely situation would be someone with a twinset on doing a wreck dive deep enough that taking a couple of minutes to cut their way out would be an issue.

My comment was just to respond to another comment about "why would I want to reach my valves anyway?" and thought Id mention the other use case.

 

[AfterDark]

Decades ago there was a rig in Europe that was manufactured to be used inverted; Divator I think the name was but not sure. I remember they were twin tanks with a smaller diameter then most tanks of the day. I thought it was a pretty good idea back then just for the fact the valve(s) were easier to reach. Not positive but the tops may have been flat like an AL80 so they didn't need boots. It never caught on.

 

[RainPilot]

@AfterDark it is indeed the Divator by AGA, now Interspiro. Made (mostly) as a system for commercial divers as a bail out from surface supplied. A lot of guys used these for rec diving as well, tiny package with about 80 cuft capacity.

http://www.interspiro.com/K7MP3/media/Products/PDF/95239B01.pdf

Theres a couple of products like this:

Inverted Twinset Cylinder Stand

Here's a possible reason as well: With an inverted tank, would you hear a valve / first stage leak? That may be a compelling safety reason.

 

[tr3a]

Divator:
If I remember correctly 4400psi twin 40's (steel). Had one in 1974-1975. Most comfortable rig I have ever owned. Was extremely negative, with 3/8" farmer john no weight belt required.

 

[rjack321]

Another thought, since the valve part is the heaviest underwater, a valve down setup would progressively make horizontal trim harder as the tank emptied. Not a deal breaker but something to consider.

This is a real issue in an AL80 and a wetsuit with some lead on the waist. All the negative buoyancy is at your hips and all the positive forces at your head.

The reality is that divers don't get entangled in the water nearly as much as internet divers do

 

[AfterDark]

Divator:
If I remember correctly 4400psi twin 40's (steel). Had one in 1974-1975. Most comfortable rig I have ever owned. Was extremely negative, with 3/8" farmer john no weight belt required.

If you don't mind me asking why don't you still have it? Pretty good recall for an old fossil at 03:39 huh?

 

[Akimbo]

Here are some threads that may be interesting:

http://www.scubaboard.com/forums/ad...ly-reach-doubles-valves-help.html#post6010430

http://www.scubaboard.com/forums/ge...-inverted-doubles-bull-barsl.html#post6428593

http://www.scubaboard.com/forums/solo-divers/408803-progressive-equalization.html

http://www.scubaboard.com/forums/basic-scuba-discussions/440235-tank-orientation.html#post6562489

 

[tr3a]

If you don't mind me asking why don't you still have it? Pretty good recall for an old fossil at 03:39 huh?

Could not get the darned thing filled past 3400psi. Local shops kept saying they were going to get a booster but it never happened. At that time time I was diving lake Superior wrecks and needed more gas, so I doubled my72's into twins.

 

[dmaziuk]

That looks like a bigger snag hazard than just a reg and valve.

That does, but a full circle on 3 or 4 "legs", like propane bottles, would not be and would work as a stand too. In horizontal trim the round "front" with all the knobs and hoses behind you could reduce drag quite a bit. Swapping tanks on a cramped boat would be a real pain, though.