Is H valve a good replacement for the pony?

[jtivat]

People are going inside wrecks and caves with H valves thinking they're safe because the H valve offers them a redundant first stage. In reality, they've added a valve that is prone to failure when they bang into something.

He did say for recreational use.

 

[Doc Intrepid]

Laurens,

what the hell is that thing on the top of your tank?

Enquiring minds and all that...

 

[El Orans]

what the hell is that thing on the top of your tank?

This thing?

 

[RJP]

This thing?

I think he was referring to the handle...

...or as I like to call it "an entanglement hazard."

 

[slackercruster]

A quality H-valve such as a Dive Rite or Thermo has little greater potential of failure than any than other options such as a K or J valve or doubles manifold. All dive eqpt. has failure points. They have offered another option to divers on single back gas tanks for years with success. You might be able to source some Y-valves from the UK at a premium price.

The use of an H-valve does offer some redundancy in that you now have 2 first stages that can be used....in the event of the primary first stage failing.

A pony bottle is a good option for single tank divers diving NDL profiles.....they are a true contingency source of gas for the singles diver and I would recommend them.

Before I switched to diving only doubles (which are the best set-up), I dove a large steel single tank with an H-valve and slung a pony bottle....that combo provides a respectable level of protection for recreational diving.

Why are Y valves so tough to find?

Someone mentioned spin issues? Are Y valves prone to spinning and loosening from the tank?

 

[slackercruster]

I don't think H-valves are that unreliable either. If they were, they wouldn't be allowed at the Intro Cave level and we have yet to have a fatality of a Intro Cave diver wearing a single tank (that I'm aware of).

There are a few disadvantages, one being that you will have difficulty renting H-valve tanks from any random dive shop but your regs will be set up specifically for using one. That can cause logistical problems in some situations--just try doing a 2-tank dive day with a K valve on one tank and a H valve on the other. Also, in order to be of any benefit you have to be able to do a valve shutoff quickly in the event of a problem.

I used to be all for H valves and didn't like pony bottles, but after rebreather training with bailouts I'm starting to see the advantages of a pony (which is really just OC bailout for OC equipment): no one gas failure can possibly jeopardize your life and require immediate action, no reliance on a buddy is required, and you can assist other divers by handing off a slung pony to them instead of being tethered with a hose air-sharing. Most of these advantages really don't come in to play in true recreational diving, though, and there are a few skills that are good to know concerning stage bottles to really take advantage of all this.

Why didn't you like pony's?

 

[slackercruster]

If you have H or Y valve you need to make sure your shutdowns are VERY fast - you only have 1 tank and it will empty quickly (especially if a problem happens at worse point of dive - just prior to ascent). If the shutdown is slow you'll lose too much gas.

My advice - get a completely redundant air source (so pony or twinset)

Good point.

Have any of you had problems with doubles where you had s to shut things down and it took longer than expected to figure out which valve needed to be off?

 

[texdiveguy]

Why are Y valves so tough to find?

Someone mentioned spin issues? Are Y valves prone to spinning and loosening from the tank?

They seem to have been replaced years ago by H-valves in popularity.....I know of no shop in the US selling new Y-valves (maybe someone else does and can reply to a US source). I know the available units from the UK are pricey. Have never heard of a 'sling shot' valve spinning loose while the valve is under tank pressure.

 

[Doc Intrepid]

This thing?

Yeah, that thing!

(I could tell the handle was a handle....or 'entanglement hazard', as you prefer!)

But the 'innovative Y-valve' was a new one. Hadn't see that one previously...

Who makes it?

And just while we're on the topic, Laurens, give me the benefit of your opinion --

I've always held that except for diving under ice, where its hell to get a set of steel doubles back up through that triangular hole afterwards, any environment where I might need a redundant 1st stage called for a set of doubles. IOW, given recreational diving, unobstructed access to the surface and all that, if I had 1st stage issues I'd rely on my buddy team to simply access the surface. If I needed a spare 1st stage in case my primary **** the bed, by definition I would no longer be "recreational" diving...

That's a pretty slick valve and reg set you have there - but what is your rationale for needing it?

(Just curious...)

Thanks!

Doc

 

[drbill]

IMHO NO... my understanding is that H-valves do not have redundant air paths.