different tank valves

[diverrick]

We just got back from a dive trip to the USVI BVI, FVI, and saw a tank valve I had never seen before.

It seemed to have two regulator ports, per tank. one was fixed, and the other had a swivel port. And the internals screwed out, depending if you wanted DIN or traditional yoke mounts.

The DM on the trip told us that they were required to have "redundant air supplies" as divemasters, by law, thus the wierd valves. End result was they had two separate regs, hooked to the same tank, thus they had "redundant" air supplies..
Have you ever heard of this setup.. seems to me they are skirting the redundant air supply idea by having two regs hooked to the same air source. It kinda defeats the whole concept of redundancy, as you still only have one tank of air to breath from.
Am I missing something here or what?

 

[dannobee]

Did it look something like this?

H Valve Pro 200-BAR reviews and discounts, Dive Rite

It's an acceptable alternative to doubles if two first and second stages are needed.



.

 

[NorthWoodsDiver]

What you saw was likely to be what we call an "H" valve or maybe one of the older "Y" valves. The idea is that they allow you to isolate off a free flowing regulator to save the air in the cylinder. some people use them and some don't depending on the dive. They are generally not considered appropriate for more technical related dives but I think thats mostly due to the actual volume of gas required for most technical dives.

Not something I personally own or use, as doubles or a slung aluminum 40 makes more sense for my diving needs.

 

[diverrick]

they looked a bit different from the pics you showed, but thats the same idea.

 

[diverrick]

after all they were french ;-)

 

[Tanked]

The DM on the trip told us that they were required to have "redundant air supplies" as divemasters, by law, thus the wierd valves. End result was they had two separate regs, hooked to the same tank, thus they had "redundant" air supplies..
Have you ever heard of this setup.. seems to me they are skirting the redundant air supply idea by having two regs hooked to the same air source. It kinda defeats the whole concept of redundancy, as you still only have one tank of air to breath from.
Am I missing something here or what?

I use H valves on my 120's. Its considered a form of redundancy in the case regulator failure, but not running out of air. Since i use a bigger tank, im not really worried about running out of air, since I can shut down one of the valves in case one of the 1st stages blow. I do ocasionally strap on a 30cu pony if i'm diving deeper than 80 feet, or solo.

 

[beanojones]

The DM on the trip told us that they were required to have "redundant air supplies" as divemasters, by law, thus the wierd valves.

FWIW. OSHA regs till require J Valves in tank based commercial diving. Government regulations are often weird.

 

[DA Aquamaster]

FWIW. OSHA regs till require J Valves in tank based commercial diving. Government regulations are often weird.

More correctly they require a redundant air supply on non surface tended dives to 100', and a J-valve oddly enough still counts.

 

[beanojones]

More correctly they require a redundant air supply on non surface tended dives to 100', and a J-valve oddly enough still counts.

While that may be a possible reading of the regulations, a project I was involved with got nailed for not having J-valves on manifolded twin 120's (and that was with divers with 2 slung deco bottles).

There was redundancy on the back gas, and two deco bottles, and they got cited for not having J-valves on the manifolded 120s.

(Very, very ***)

 

[widget]

It seemed to have two regulator ports, per tank. one was fixed, and the other had a swivel port. And the internals screwed out, depending if you wanted DIN or traditional yoke mounts.

Yes, as has been said, its a standard H - or Duel Valve, quite common in Europe, here and other areas,it was initially designed for the commercial and technical enviroment, but is even popular for leisure / recreational divers now as well.

Very common in the commercial and recreational world here, actually we use them on all our cylinders as well.