Valve question

[ACR]

What are the advantages/disadvantages to using an H-Valve?

Does such a valve provide adequate redundancy when using a high-volume air supply (like a 130)

 

[MikeFerrara]

The advantage is that it provides a second reg and valve allowing you to isolate any failure down stream of each valve. Whether or not I would consider it "adequate" would depend on the dive.

 

[Jimmer]

Your gas supply is not redundant with an H valve, in the way that it is with doubles. But your regulators are. So in the event that you had a freeflow or some form of regulator failure, you'd have redundancy. If you had a tank neck O ring rupture, an H valve doesn't help with anything.

 

[ACR]

If you had a tank neck O ring rupture, an H valve doesn't help with anything.

What's the likely hood of something like that happening? It seems the tank neck & valve are pretty solid bits of hardware.

 

[Jimmer]

I don't think it's very likely. I only personally know of it happening once, and that was land. I've never heard of it happening in the water. One thing I look at with an H valve, is it can make for a decent transition to doubles. You'll have the regs setup for doubles, and assuming you have 2 tanks with opposite facing H valve, all you need is the isolator crossbar and bands.

 

[ACR]

One thing I look at with an H valve, is it can make for a decent transition to doubles. You'll have the regs setup for doubles, and assuming you have 2 tanks with opposite facing H valve, all you need is the isolator crossbar and bands.

Thats in line with what I'm thinking. Though if it's not going to provide any real redundancy than it's not worth the trouble.

That being said if what it's supposed to provide redundancy against has the same odds of happening as me being eaten by a shark in Georgian Bay while being struck by lightning and winning the 6/49 it may not be that big of a deal.

But then again, I don't really know what I'm talking about.

 

[Jimmer]

That being said if what it's supposed to provide redundancy against has the same odds of happening as me being eaten by a shark in Georgian Bay while being struck by lightning and winning the 6/49 it may not be that big of a deal.

If that happens, you officially became the coolest person I've ever met.

If it were me, I would skip the H valve, and with the second reg, sling a 40 cf bottle. Then you have the second reg when you go to doubles, and you have the 40 when you go to deco.

 

[ACR]

If that happens, you officially became the coolest person I've ever met.

If it were me, I would skip the H valve, and with the second reg, sling a 40 cf bottle. Then you have the second reg when you go to doubles, and you have the 40 when you go to deco.

That makes a lot of sense Jimmer... and I thought I was already the coolest person you've met??

 

[texdiveguy]

I have a st hp130 with an H-valve on it....it is great for having redundant regs.. When I dive this tank I still carry a slung pony as redundant gas. As to the question of valve to tank o-ring failures---pretty slim...I had one on land years back---my fault for not seating the valve enough to the tank.

 

[MikeFerrara]

I haven't seen any tank neck o-rings fail but I have seen burst disks fail.