A Reg that can't freeze??????

[TRUETEXAN]

I just got through reading a paragraph in " the Modern Sport Diver Catalog" that said, " Do not throw away your old double hose regulators, instead keep them and use them for extreme ice diving because they will not freeze like a modern single hose reg can."

Does anyone know if this is true or not? If it is true, can you explain why?

 

[neil]

Tex,
I think I got it. In a double hose reg, there's no water next to the valve to freeze. The mouthpiece is a long way from the second stage valve, and the hose is filled air.
In a single hose reg, the second stage valve is exposed to the moisture of exhaled breath and wetness from the surrounding water.

Also, double hose regs are diaphragm regs, and there's no danger of freezing around a first stage bias spring.
I've also heard that possibly the large body of the reg helps equalize temperature more readily than the small body of a single hose. Maybe?

Neil

 

[pescador775]

The first and second stages of the double hose are isolated, not only from seawater but from diver exhalations as well. As long as the air supply is reasonably dry the double hose will not freeze up.

In addition, they will not sand up when beach diving or mud up when working a wreck using suction dredge, etc.

 

[Norm]

Folks have listed the reasons for double-hose dependability below but remember what several reputable manufacturers have told me personally:
"There is no such thing as a freeze-proof regulator"!
(Under the right circumstances any regulator can freeze)

 

[pescador775]

What do your reputable manufacturers know about 2 hose regulators? Nada.

 

[otter-cat]

If double hosed regulators are better at preventing freezing, why aren't they used anymore, or at least used more commonly in cold water?

I dive in cold waters (though no ice around) and specifically sought out a reg that was good for cold water use. In my search, I never saw anything about double hosed regs.

I'm still fairly new to diving and don't know that much about gear, so if anyone knows the answers to these questions, I'd love to know.

Thanks,
otter-cat

 

[Norm]

At last check the only manufacturer of double-hose regs for scuba was Nemrod. (I don't know if they still make them or not)
Many of the double hose regs had only one stage. It was encased within the sheetmetal in which your warmed exhaust passed through. (At least that's the way the three I have are made) They weren't great breathers and they demand a very unique effort to buddy breathe. Several current manufacturers make regs for rebreathers. They DO "know nada"
Norm

 

[neil]

Nemrod went out of business just in the last couple of years, I believe. They made the Snark DH reg up until the last. It was not the best DH reg ever made by any means.

Norm, depending on which regs you have, they are probably two stage regs. Both stages are encased in the housing. The only single stage double hose reg I know of is the old USD Mistral, and I'm sure some others.

Otter cat,
The double hose regs were not good breathers, and any modern reg designed for cold water is better.
The problem was that the reg was behind and above you, and the mouthpiece was below you. You had to overcome the pressure differential between the depths and pull the air down to the mouthpiece. It sort of feels like a low performance modern single hose reg (maybe not that good ). Plus you have to move the expired air back up the exhaust hose to the housing and out the exhaust valve.
Neil

 

[otter-cat]

Thanks for the clarification, Neil! Of course, now that makes me wonder why the magazine TRUETEXAN read is recommending their use for ice diving. Wouldn't that type of diving best be done with the most modern reg technology available?

Just wondering.

otter-cat

 

[Fishkiller]

that wouldn't freeze is the MARES ABYSS... I am sure APEKS makes one as well...

of course I would like to know without using the search features of this Internet thingy as to why the change to the single hose...