HP steel tanks in cold water
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I do ice diving in 0°C (32°F) freshwater with tanks filled to 250bar (3625 PSI) with no problems, also during the winter we often go diving when it is -10 to -20°C in the air and 2-4°C in the saltwater with tanks filled to 330bar (4786 PSI), and regulator freezing is not a big problem. Of course I am using freeze protected and environment seald regulators and take measures to reduse the risk of a free flow as a result from a regulator freeze.
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Wow! Thanks for sharing your photos and fill pressures. Those are certainly extreme conditions. I'm feeling chilled after only reading your post.I do ice diving in 0°C (32°F) freshwater with tanks filled to 250bar (3625 PSI) with no problems, also during the winter we often go diving when it is -10 to -20°C in the air and 2-4°C in the saltwater with tanks filled to 330bar (4786 PSI), and regulator freezing is not a big problem. Of course I am using freeze protected and environment seald regulators and take measures to reduse the risk of a free flow as a result from a regulator freeze.
Stoo
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As others have pointed out, the pressure in your tank isn't really relevant in this conversation. Your regs will reduce this down. Most of us have our IP tweaked to me a bit lower than spec, and if your second stage is adjustable, dial it back.
Having said this, some regs are better in cold than others. If you are planning on going deeper, and if you don't have some redundancy, then a freeze-up can be a nasty affair. Sealed first stages are a really good idea.
Also, be sure to get your fills from a local shop. Cold water shops tend to pay more attention to the moisture level in their air. My regular fill shop leaves me feeling pretty parched... i often take sip of water while diving, and a cold beer after the dive if critical.
Beyond regs, in theory you could have issues with inflators... although unlikely when the air is warm.
Having said this, some regs are better in cold than others. If you are planning on going deeper, and if you don't have some redundancy, then a freeze-up can be a nasty affair. Sealed first stages are a really good idea.
Also, be sure to get your fills from a local shop. Cold water shops tend to pay more attention to the moisture level in their air. My regular fill shop leaves me feeling pretty parched... i often take sip of water while diving, and a cold beer after the dive if critical.
Beyond regs, in theory you could have issues with inflators... although unlikely when the air is warm.
My limited understanding is that in theory and experimentally, greater adiabatic cooling will take place in first stage regulators as tank fill pressure is increased. However, the higher tank pressure will not impact second stage adiabatic cooling, as IP should be relatively unchanged by tank pressure. And it appears that in practice, if one uses a good sealed first stage regulator, high fill pressure is not considered to be a known risk factor by the people who routinely dive in cold or Ice conditions.
We are in agreement. That is what I was attempting to communicate, while also pointing out that I had a reasonable basis for asking the question in the first place. The poster Stoo had just stated that the pressure in your tank wasn't relevant to the conversation, which I disagree with. That was the original question I asked. Irregardless it has been an informative discussion. I appreciate all the good tips and comments.
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I've dived in 3-4C (37-39F) water and -10C (15F) air with 300 bar (4350psi) tanks and haven't had a problem. I've also dived in 3-4C water with a 200 bar (2900psi) tank and haven't had a problem. I've never considered fill pressure a factor when diving in really cold water.
If you have a good sealed 1st and avoid breathing out into your 2nd on the surface, you'll probably be OK. Besides, a 2nd stage freeflow (the only type I've ever experienced or witnessed) normally happens on the surface, not at depth, and it isn't critical. Sure, it's a nuisance and you have to close the tank valve to stop it, but it isn't really dramatic. It just seems a little dramatic.
If you have a good sealed 1st and avoid breathing out into your 2nd on the surface, you'll probably be OK. Besides, a 2nd stage freeflow (the only type I've ever experienced or witnessed) normally happens on the surface, not at depth, and it isn't critical. Sure, it's a nuisance and you have to close the tank valve to stop it, but it isn't really dramatic. It just seems a little dramatic.
cool_hardware52
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I dive cold water all year round.
Yes, regulators do sometimes freeflow, so what?
Avoid inflating your wing/jacket/drysuit when inhaling from the second stage attached to the same first stage as the inflator.
As long as the gas in your tank is dry it does not matter how cold the surrounding water is (as long as it is not solid
In really cold water I dive with a redundant air source.
Yes, regulators do sometimes freeflow, so what?
Avoid inflating your wing/jacket/drysuit when inhaling from the second stage attached to the same first stage as the inflator.
As long as the gas in your tank is dry it does not matter how cold the surrounding water is (as long as it is not solid
In really cold water I dive with a redundant air source.
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