Valves up or down? Considerations...

[Schwob]

(If thread needs to be moved elsewhere, please do).
I was unsuccessfully trying to find good info on diving in doubles with the valves pointing down versus with the valves pointing up. To me (slight issues with mobility), it seems that if the tanks are mounted "valves down", they might be easier to reach, may need protecting with a cage of sorts (setting down rig...) and hose routing will differ. So what's the rub? Why does it seem like everyone in the US dives "valves up". I think some in the British Isles prefer valves down. Maybe some ex "forces" divers (from some countries) too. Why?

Can you enlighten me or point me to good info on the pros and cons and "how to" of "valves down" with double backmounted cylinders?

 

[RyanT]

I thought a lot about this when I first started diving doubles. There is no question that having the valves down will make them easier to reach and manipulate. On the other hand, with practice, most divers can manipulate their valves when pointed up. Once you learn to manipulate your valves in the upright position, the logistics of upside down mounts and weird hose routing just doesn't make it worth it. I'll admit, that as someone who is not mobility impaired, manipulating my left valve is always more difficult for me; my left shoulder just isn't as flexible. For someone who physically couldn't reach upright valves, I could see upside down mounts as a possible solution though.

 

[Blue Quaker]

I had a student take an Advanced Wreck class who had reduced mobility due to a martial arts injury that permanently reduced the range of movement in one shoulder which made reg. isolation/valve drills with standard double tank configuration impossible. He finished up with double 95s inverted, with a cage to protect the manifold when setting tanks down. He used 5ft and 10ft hoses on his regs so he could route the hoses between the wing and the doubles(same side as his body, not open to entrapment) so the hoses "came out" over the shoulder and the regs then appeared and functioned as normal. He was easily able to do his valve drills with the tanks inverted. It is one way to get by. There was no chance of damaging/dislodging his regs when going through a restriction in that configuration

 

[KenGordon]

Nigel's twinset rig

 

[Diver0001]

(If thread needs to be moved elsewhere, please do).
I was unsuccessfully trying to find good info on diving in doubles with the valves pointing down versus with the valves pointing up. To me (slight issues with mobility), it seems that if the tanks are mounted "valves down", they might be easier to reach, may need protecting with a cage of sorts (setting down rig...) and hose routing will differ. So what's the rub? Why does it seem like everyone in the US dives "valves up". I think some in the British Isles prefer valves down. Maybe some ex "forces" divers (from some countries) too. Why?

Can you enlighten me or point me to good info on the pros and cons and "how to" of "valves down" with double backmounted cylinders?

Well.... I've been involved in I-don't-know-how-many discussions about this over the years but I can summarize everything I've ever heard about it in a couple of lines.

1) it works
2) there are some complications, some of which deserve careful contemplation, but it works
3) it's taboo, but it works

I once knew a guy who had shoulder injuries related to racing motorcycles who did this. At the time the DIR world war was happening and the reactions he got ranged from

- oh? ok, cool.... whatever... you bloody outcast.
to
- I see risks and complications and blah blah blah blah blah from people who dove mostly behind a keyboard
to
- If you can't reach your valves in the "correct" position then you are not a proper diver (the word used was "stroke") and you should stop diving

Some of that is still present in the diving community and I'm sure you'll see it on this thread too. My conclusion, after 15+ years of he-said-she-said about this on the internet is that if you want to make it work, you can. Full stop.

R..

 

[Blue Quaker]

Nigel's twinset rig

This looks like what my student did in 2003 in Tobermory.... It worked fine. The military gas management system that the guy in the website mentions was known as double decanting... Royal Navy used to do it.

 

[Diver0001]

Oh, I see Ken found it. I was, indeed referring to Nigel Hewitt above.

His timing was so unfortunate. He endured one of the most cynical attacks against an intelligent diver (and intelligent man) I had ever seen online. His patience with the POV warriors at the time could only be described as "enlightened". I know for SURE that I would have thrown off the gloves for things that he saw as "offering an alternative". I don't know what he did for work but he should have been a professional diplomat.

R..

 

[Boiler_81]

Thank you for bringing up this topic. I broke my right elbow 10 months ago. Up to three weeks ago, I had three plates and 23 screws in it. My Doctor says I should regain most of my range of motion in time. However at the moment I can only bend it to 90 degrees. I had planned on doing a deco course this summer and knew I wouldn't be able to reach back mounted valves and am not that interested in sidemount diving.

Inverted back doubles look like the perfect solution.

 

[tbone1004]

I have no issues with them and the CCR guys almost exclusively dive with valves down *exceptions being the GUE guys with their funny manifold, Poseidon recreational version, and I think that's it*. The issue now is finding the cages for the doubles so they will stand up. Personally, I don't believe it's worth the hassle, and if you have mobility issues of just reaching the isolator, then dive independent doubles *I do quite regularly, it makes filling a PITA though I have built a fill whip to fill both of them simultaneously, and it means you have to switch regulators which will irritate DIR divers, but I do that anyway*, or dive sidemount.

 

[eelnoraa]

For recreational setup, single or double, I think the main difficulty is to find a commercial available. Most people are not going to be able to fabricate their own bracket, myself include. So I guess when I can't read the valve, I will just go side amount