Using a regulator in cold water.

[softballer]

I am trying to understand a bit about about cold water regulators. At what temperature is it recommended to stop using a standard non-enviromentally sealed regulator?

Is there some type of threshold like anything below 50 degrees?

 

[fjpatrum]

I am trying to understand a bit about about cold water regulators. At what temperature is it recommended to stop using a standard non-enviromentally sealed regulator?

Is there some type of threshold like anything below 50 degrees?

God I hope not... my regs aren't sealed and most of my diving is in 40ish degree (F) water so far.

What little I've read is that's about the temp though, below 38-40 get environmentally sealed.

 

[rcolsen]

below 38-40 degrees seems high but I'm a newbie. I have a non-sealed reg but was told that a cold water kit has been installed at my annual. I think thats just silocone grease. I've had it in water closer to freezing than 38. Again I dont know enough to have a good opinion.

 

[DivingPhan]

one thing: it would depend on if its salt water or fresh water diving but i would say with under 38* should be environmentally sealed

 

[scubadiver888]

I am trying to understand a bit about about cold water regulators. At what temperature is it recommended to stop using a standard non-enviromentally sealed regulator?

Is there some type of threshold like anything below 50 degrees?

Regulators and manufacturers haven't really standardize things that much. Some manufacturers will claim anything above 40F is considered warm water. Other manufacturers might say that anything above 50F is warm water.

The big concern with using a 'warm water' regulator in 'cold water' conditions is freeflow. There is a spring which controls the flow of air out of the cylinder and through the first stage. If the regulator is environmentally sealed, the spring is isolated from the water. This means the water cannot freeze inside the spring and cause it to stick open. However, moisture inside the spring area can still cause the spring to stick open.

Some manufacturers will seal the spring with oil. If the oil is good to -10F then there is little worry it will cause the spring to stick open.

The other way a manufacturer combats freeflow is making the first stage out of ALL metal rather than some plastic. The metal is better at conducting heat. If the adiabatic expansion of air leaving the cylinder causes the temperature of the first stage to drop below 32F then the water will freeze. If the first stage is all metal and very open, the warmer water (40F is warmer than 31F) will heat up the first stage and prevent it from freeflowing.

So environmentally sealed usually helps make a regulator function better in cold water but you can have a non-environmentally sealed regulator which is as good for cold water.

As to your originally question, 50F is a good gauge for cold water. Anything below 50F would be considered cold water by most.

 

[knowone]

below 38-40 degrees seems high but I'm a newbie. I have a non-sealed reg but was told that a cold water kit has been installed at my annual. I think thats just silocone grease. I've had it in water closer to freezing than 38. Again I dont know enough to have a good opinion.

It would be a good project, to find out.

I use 40 year old unsealed regs both piston and diaphragm in less than 50
but I think technique may also have something to do with it.
Avoid a purge test above or submerged.

 

[SDAnderson]

I'm not certain that there is a "generally accepted" definition of cold water, as you've seen in the responses in this thread. To the extent that there is one, 50F seems to be the most prevalent. I don't know of anyone that uses less than 40F as their definition. The wusses in Florida seem to use 70F.

Consider this: there is an inverse relationship between the volume and the temperature of a gas. The air passing through your first stage valve expands dramatically. All other things equal (and they aren't, at least not in your regulator, where humidity, materials and frictive heating confuse the issue) the temperature drop can exceed 10F for every 1/4 ata. If the supply cylinder is at 3000 psi and the IP is set to 140psi, you're looking at a whole lot of adiabatic cooling. If the regulator and supply gas have cooled to ambient and the IP side of the first stage is exposed to that frigid stream of air, any water it comes in contact with is going to freeze solid.

Technique, design and materials can help extend the safe range for cold water diving with an unsealed regulator but puts you near the ragged edge where any problem can tear the envelope open and add to the likelihood of a cascade failure. I do a lot of cold water diving and have settled on environmentally sealed diaphragms any time the water temps fall below 50F. My experience has been that oil (or lube) sealed pistons also work but are messy, expensive to maintain and failure prone.

As always, YRMV.

 

[mateo1147]

I experienced slight icing of my regulator last weekend. I was diving in fresh water with an air temp of 32F and a surface temp of 42F. When I made it to my destination, I had water temp of 38F @ 117'. When ever I would look down instead of horizontal my second stage would start to free flow. If this would have gone to full free flow I would have had to switch to my pony and turn off the valve on my main to let my regulator thaw out while on my way to the surface.
After reading some of the posts on here I will be upgrading to an environmentally sealed or all metal reg.

 

[SDAnderson]

I experienced slight icing of my regulator last weekend. I was diving in fresh water with an air temp of 32F and a surface temp of 42F. When I made it to my destination, I had water temp of 38F @ 117'. When ever I would look down instead of horizontal my second stage would start to free flow. If this would have gone to full free flow I would have had to switch to my pony and turn off the valve on my main to let my regulator thaw out while on my way to the surface.
After reading some of the posts on here I will be upgrading to an environmentally sealed or all metal reg.

Sounds like you were getting a little dribble of air when you looked down, not a roaring free flow. If looking down started the free-flow, the problem was in your second stage, not your first stage, and won't be solved by an environmentally sealed regulator. In that case, reducing the first stage IP or increasing the second stage CP might help solve your problem.

Freeze-ups maybe more common in the second stage than in the first. That's a bummer but the fix is also less aggravating - a few minutes on your alternate and the primary should have absorbed enough heat from the water to thaw.

Still, environmentally sealed first stages in water as cold as you were diving are a sensible precaution.

 

[LakeCountyDiver]

I don't know of anyone that uses less than 40F as their definition. The wusses in Florida seem to use 70F.

Hey no need for the name calling. Just because we have some of the best diving in the world and it is all in water that is at least 72F to 92F does not make us wusses.
I was told buy a buddy that does ICE diving (he's nuts) that his threshold is 40F.