Appeared in DIVER December 2006

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CYLINDER VALVE Beuchat H-Valve

British divers seem to be in love with pony bottles. They like to strap them to the side of their main tank so that they have a redundant 3-litre supply of gas for use in an emergency, but this turns an otherwise comfortable single cylinder into an unbalanced and uncomfortable weight on the back.
How does an H-valve help Instead of diving with a 15-litre supply of gas divided into 12 and 3 litres, why not use a 15-litre tank with an H-valve This allows you to designate any part of those 15 litres as your fallback supply should your primary regulator let you down on a dive.
You use it in exactly the same way as a twin-set. Two cross-flow valves are mounted together, each with its own method of opening and closing.
I use mine with the regulator fitted to the left side supplying my BC direct-feed, and a transmitter for my tank-pressure display on my computer. The regulator on the right supplies the direct-feed to my drysuit and a high-pressure hose and conventional contents gauge. I can even fit an octopus rig to either, if I want to.
In this way I get complete redundancy with two totally independent regulators, and always have a method of providing buoyancy if I need it.
In order to fit two regulators without getting headaches from sorting out hose routeings, one side of the H-valve rotates. That said, the only hose I use on the left-side regulator coming over to the right is one to that regulators second stage.
I go in the water with both sides fully turned on. Should my primary go into free-flow, for example, its no great shakes to reach back, or even pull the set over my head and turn it off. An H-valve turns every single cylinder into a twin-set.
But its the same reservoir of gas, I hear you protest.
What if youve run out of air Theres no redundant supply!
Well, I consider my reserve to be the last 50bar (or 3.75 litres at full pressure) of gas in my 15-litre cylinder that started the dive with 200bar. Thats more gas than a pony has. I dont touch it unless I have to.
This does mean watching your contents gauge and managing your air supply. But if you cant do that, theres a good chance youre walking down the hard shoulder of a motorway with your petrol can, having run out of fuel on the way to the dive site!
What if an O-ring blows on your tank during the dive Turn that side off and make your way calmly back to the surface, just as you would with a twin-set.
The Beuchat H-valve is equipped with DIN threaded connections together with an A-clamp adaptor. It costs 69.99. One day, all single tanks will be equipped this way.
  • Alpha Distribution 01709 515157, www.beuchatuk.com


  • Divernet
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    + Total redundancy
    + No need for a pony cylinder


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    - None, unless you insist on separate gas containers