H-Valve vs Y-Valve

[Texasguy]

For some reason Y-Valves are no longer made. At least they are not for sale. Yet, H-Valve seems to be easy to buy.

Questions:
1) Are there any features that are different from Y to H? From what I see H is more modular, is there anything else?
2) Why Y valve has lost its popularity?

Thank you

 

[NAM001]

A Y valve has two seperate air paths to the tank, one for each valve. If you have ever seen a valve off the tank you dee a tube protruding fromthe bottom of the valve. The Y valve has 2. The h valve has one path to the tank bot valves share this one tube. If you want some Y valves i thisk i can tell you where to get some.

For some reason Y-Valves are no longer made. At least they are not for sale. Yet, H-Valve seems to be easy to buy.

Questions:
1) Are there any features that are different from Y to H? From what I see H is more modular, is there anything else?
2) Why Y valve has lost its popularity?

Thank you

 

[Dr. Lecter]

The independence of the Y-valve's pathways is largely illusory--anything that blocks one dip tube will likely block both. And as you noted, H-valves are modular; easily converted to single tank or manifolded doubles. The Y-valve was a net inferior design and has been discarded as such, except by those more interested in sentimentality than functionality.

 

[MRadke]

Isn't the reason for the Y valve to have independent regulators in the event one is froze? The Y valve that I have has shut offs on each leg and would seem to be a good solution for someone that doesn't want to deal with the expense of doubles.

 

[Bob DBF]

When I was looking into Y and H valves, I ran into an H valve with completely separate paths, including 2 dip tubes. I have no idea where I ran across them, but if you look it's somewhere on the internet. Good luck.

Let's face it, if you clog both dip tubes on a y valve, you should probably look into your tank a bit more often. I haven't seen real dip tube clogging crud in a tank since divers started taking the annual VIZ seriously.




Bob
-----------------------------------
There is no problem that can't be solved with a liberal application of sex, tequila, money, duct tape, or high explosives, not necessarily in that order.

 

[nimoh]

Isn't the reason for the Y valve to have independent regulators in the event one is froze? The Y valve that I have has shut offs on each leg and would seem to be a good solution for someone that doesn't want to deal with the expense of doubles.

yes, that's the reason. If you have an outboard failure, you can shut down one reg and still access the gas through the other. For an inboard problem (tank neck o-ring, pressure relief valve) you are screwed (although inboard problems are very uncommon). Using manifolded doubles, for an inboard problem you can close the isolator and still have access to half your gas (i.e. one tank). Another (minor) advantage of doubles is that because the valves are further away from each other, it is sometimes easier to determine where the gas leak is coming from and speeds up the problem solving.

However, IMO the reason for Y valves going out of favor is that a pony bottle provides much better redundancy.

 

[turnerjd]

Y and H valves are both popular on this side of the pond. Two first stages are used on the backgas on almost all deco dives, and Y valves are 'cheap as chips'. Many different styles and makes are available. One piece Y valves are preferred by many over modular H valves as they have fewer failure points.

Robinets - Robinetterie et accessoires

Jon

 

[lowviz]

...//... Y valves are preferred by many over modular H valves as they have fewer failure points. ...//...

Which means that you can't shut off one side or the other. However, they are symmetrical about the cylinder, while H-valves are not. I wish someone would make an H-Y valve...

 

[PfcAJ]

Every Y valve I've seen has been able to independently shut off both regs.

 

[turnerjd]

Which means that you can't shut off one side or the other. However, they are symmetrical about the cylinder, while H-valves are not. I wish someone would make an H-Y valve...

I must be missing something here..... A Y valve has two independent exits, and one, the other, or both can be used, or not, as required.

Jon