1st Stage Freeze Up Prevention

[Vin]

I do allot of cold water diving up here in the North East and frequently run into 1st stage freeze up. The only trick I know is to keep the req submerged and mouth peice down proior to breathing and if need be - give it a whack to stop free flow.

I am doing my ice cert this month and was reading the board for tips + techniques.

Pez de Diablo wrote "environmentally sealed 1st stage to prevent freeze up" on another thread... re: ice diving.....

please detail- sounds like something I need to know. And are there any other tricks board members can share?


Thanks


Vin



environmentally sealed 1st stage to prevent freeze up

 

[Vin]

Oh Yeah- for those intrested - Call Atlantic Diver's Saugus Ma. This Last 2 weekends in Feb- We'll be heading out!

 

[roakey]

Doubles -- if a reg freezes you shut down that post, let it thaw (30 seconds?) and turn it back on.

Roak

 

[The Fresh Prince]

Doubles -- if a reg freezes you shut down that post, let it thaw (30 seconds?) and turn it back on.

Roak

Also, if you inflate your wings for bouyancy when you get in, put it in while it's in your warm vehicle. Common failure as adibiatic cooling on shore or on surface, will freeze it solid.

 

[Vin]

Wait - I am not clear....

Doubles - reffering to redundant systems ?

And - I am not clear on the second suggestion..... please detail

vin

Also, if you inflate your wings for bouyancy when you get in, put it in while it's in your warm vehicle. Common failure as adibiatic cooling on shore or on surface, will freeze it solid.

 

[DA Aquamaster]

You do not want to test your reg or inflate a BC or dry suit while out of the water just ebfore the dive as it will supercool the reg and maek it more likely for ice to form in the reg once you submerge.

And with doubles, you can shut the reg off and the ice on a first stage will thaw in a minute or so. An iced second stage will thaw even sooner.

Low pressure tanks reduce the adibatic cooling load as the pressure drop is much lower so LP steel tanks make sense if you do a lot of cold water diving. With any tank, you need to be more careful early in the dive when tank pressures are higher as the reg will cool more when flowing air.

An environmentally sealed second will eliminate the water coming in contact with the cold internal parts of the reg. This is done with a diaphragm or a silicone grease transmitting water presure to the ambient pressure chamber.

A diaphragm seal is theoretically more efficient right up until it leaks at thich point a freeflow is virtually certain. Plus in most cases you have to accept the limits of a diaphragm reg design. One exception is a diaphragm sealed piston design which gets a little complex with a one way valve to keep the ambient chamber dry and a shraeder valve to keep the ambient chamber properly pressurized.

Silicone grease with a protective boot works well as long as the silicone is properly packed in the ambient chamber and is kept topped off over the season. O2 clean concerns exist though with most environmental "silicones" so for high O2 applications over 40% it could be a problem. Although I think any risk is very very minimal with a piston design using a backup o-ring as the chance of any silicone migrating across both (02 clean lubricated) piston head 0-rings is very, very small.

 

[quimby]

An environmentally sealed second will eliminate the water coming in contact with the cold internal parts of the reg. This is done with a diaphragm or a silicone grease transmitting water presure to the ambient pressure chamber.

I have done a bit of ice diving and lot of cold water diving but not recently and other than ice at the surface have really not seen any freeze-ups. Its really not a concern down here, but I do admit that I dont understand the "enviro kit" as its insulating aspects seem counter productive except for ice external to the dia or piston. Also that would seem to be better served by me by just greasing the housing and dia( or piston) for any ice not to adhere. Has anyone physically seen ice outside of the dia or piston, I realize the cage etc in the way but I just cant imagine it happening although there has been enough written on the boards to elevate it to unresolved problem status. My only thoughts go along with the moisture in the air supply but thats pretty obvious and generally been ruled out on the posts.

 

[jonnythan]

Is it even possible for a completely sealed first stage (DS4 for instance) to freeze? I've seen pictures of those or the Xstream first stages covered in a thick piece of ice but continue to work.

 

[Bob3]

Is it even possible for a completely sealed first stage (DS4 for instance) to freeze? I've seen pictures of those or the Xstream first stages covered in a thick piece of ice but continue to work.

Having a "freeze resistant" 1st stage is a good start, that will take care that end of the hose. Then you have to worry about the 2nd stage making mischief.
Here's a little write-up that's probably posted elsewhere on the board:


"Regulator Freeze 101"

There's no set temperature where regulator freezes occur; the colder the water, the more likely it is to happen. Some manufacturers use 40º F (4½º C) as an arbitrary number to define conditions where icing may possibly commence.
Both saltwater AND freshwater can get down to 28º F (-2.2º C) and not turn solid if kept moving, such as in a heavy surge or current.
The most common type of regulator freeze-up is the first stage. Unless you're using an environmentally sealed reg, there is water inside your first stage. That water freezes from the air absorbing heat upon expanding (compliments of a set of physical laws similar to those that make your referigerator work).
The result is overpressurization of the second stage, resulting in a free flow. Most folks THINK their second stage is frozen up, but it's actually the first stage that causes the second to malfunction.

Second stages do freeze up, tho mostly on the surface from breathing in them when air temp, wind chill, etc is below freezing. Simple solution: Don't stick the reg in your mouth until you're underwater. Also, keep the fingers off the BC & drysuit inflator buttons, they will "pre-chill" the 1st stage, setting up conditions for a freezeup when it does hit the water.
The other type of second stage freeze is much more rare, in that the water temp almost always has to be below freezing & you have ice build up inside the regulator from breath condensation.
This can happen to even the BEST freeze-proof regulator if the conditions are right.
Hint... double hose regulators don't have this problem. To date, the most all-around freeze-proof reg is still the double hose.

Tip for folks using a separate bottle for drysuit inflation: Install a pop off (overpressure) valve on an LP port of the regulator. In the event of freezing, you won't have to worry about having a hose blow (or the valve on your suit explode or give you runaway inflation).

 

[SDAnderson]

Is it even possible for a completely sealed first stage (DS4 for instance) to freeze? I've seen pictures of those or the Xstream first stages covered in a thick piece of ice but continue to work.

Yes. I had one freeze on a 120 ft bottle when I pressurized it at the first stop a few months ago - had to feather the valve all the way up to the 50 ft stop where the thermocline took us from 34F to 38F and the thing finally thawed.