H & Y-valves

[large_diver]

I have been into a local dive shop here in central Switzerland a few times and have had some discussions with them about tanks and gear configurations (using my somewhat rusty German). It appears that many folks here (at least at this shop) use H or Y valves for additional safety.

When I asked one of the divemasters about it, he said it is for safety, especially in cold water. I told him that I dive single tanks year round in the Boston area with a regular K valve and he looked at me like I was a little crazy.

Are H/Y's the "standard" in Western Europe?

-Chris

 

[El Orans]

Over here they aren't.

 

[TimIng]

Not standard in the UK but I and my buddy use them. The biggest benefit is not having to haul a pony around as you have two separate valves and first stages.

The other benefit is for those like myself that might regularly swtich between singles and twins. I can keep the rest of the rig, including regs exactly the same (except weights) without having mess around swaping hoses etc.

An H yalve also makes the tank a lot easier to carry.

HTH

Tim

 

[large_diver]

Thanks guys for the replies.

I heard back from another diver here in Switzerland that at deeper depths in the lakes here in Switzerland, water temps are often around 4C. Apparently if you start breathing hard, and you have damp air in the tank, the drop in temperature accompanying the drop in pressure can cause water vapor to freeze your reg and produce a freeflow. This person said that it has happened to him at least once and to others in his dive club several times.

As a result, H/Y valves are the norm.

Not sure if this is a salt vs. fresh water thing......

-Chris

 

[TimIng]

Not sure if this is a salt vs. fresh water thing......

-Chris

Certainly I've seen way more freeflows in cold freshwater than anywhere else and so this would lead divers of those waters to try and counter the risk of a problem. In other countries divers will add a pony for redundancy. Having used both options I prefer the H/Y valve. Of course you have to be able to reach the valves to be able to turn them off if necessary. If, for some reason you can't, then a pony is probably the best solution.

Tim

 

[chrisch]

Standard in most of France and Italy. In France they are a legal requirement for instructors. I use them as it saves messing about with different reg configurations between singles and twins.

Being able to isolate a free flow is a good idea. Avoiding it in the first place is better.

Chris