regulator freezing up

[tddfleming]

Yet another question about regulators. When a newer reg would freeze, are they suppose to freeze open and cause a free flow or do they and can they freeze closed and prevent you from getting any air at all?? I had a free flow while back out in the colder water, spoke to the shop I bought it from about this, the owner had mentioned to be careful to prevent it from freezing. I was not able to talk to him at that point as he has a class he was leaving for. When talking to someone else about this, they mentioned that he was told the newer regs will only freeze open and allow a free flow. I just want to find out what is true. Can anyone shed some light on this for me?

Thanks

 

[irishsquid]

All the frozen regs I've personally seen and heard about resulted in a free flow.
Granted I haven't seen that many so you may want to wait for some of the folks who have been in this for a much longer time than me to chime in.

 

[tstormdiver]

Most modern day regulators are of a downstream design. They will normally fail open. You really do not want it to fail closed, as you can breathe off the bubbles to get to the surface (I've done it from 95 ft). If it failed closed, you would suddenly be without air at goodness knows what depth. Just get an instructor or someone familiar with the technique of breathing from a free flowing regulator to show you. It's not a hard skill to do, just takes a little practice. It is a very good skill to have, if you are going to dive in cold waters. Given the right conditions, even a freeze- up resistant regulator can freeze up & free flow. I am not sure what kind of regulator you have,... If it has an adjustment knob on the second stage, you can dial it back a bit to make it breathe harder, which can help prevent (notice I did not say stop) a freeze up/ free flow.

 

[lsorensen]

We were taught how to breathe from a free flowing reg in the pool for OW. Maybe that's because it can be cold up here. Or maybe it's just a good idea to know.

 

[ECpirates96]

The thread above is correct most manufacturers are smart enough to use a downstream design that will result in a freeflow. If you are diving in conditions that are that cold consider a sealed design like the HOG with coldwater kit or the Scubapro MK17. As for the training it is easy to learn and I was also taught this in my OW here in NC in 1995. Instructer was a retired Marine so maybe that had something to do with it.

 

[tddfleming]

We were taught in the pool as well. It is not the free flow that scares me it is the frozen closed that does. I have an Oceanic EOS 2nd stage and a Oceanic CDX5 1st. Dialing back does help some. Waters being 53. The way the owner said about not wanting it to freeze up made me wonder about the open vs closed.

 

[tstormdiver]

I have an MK25/ S600 & dive it in 42 degree water. To date & after 400+ dives in that water, I have only had 1 freeze- up/ freeflow, & that was a fluke happening. The big thing in cold water with a high performance regulator is to watch how much air is going through the 1st stage at 1 time. You will not see me inhaling & inflating my wings or drysuit at that same time. I am also cautious not to "hoover" on the regulator. When you crank open the cylinder valve, you've seen the valve freeze up. The air that comes out of the cylinder into the regulator is about 10 degrees below ambient. At 42 degree water temps, that tells me that it is right at the freezing mark. Generally a regulator is designed to fail open, not closed.


I would imagine, it would have to be a pretty severe malfunction (notice: not freeze up) that would cause the regulator to not give air. I can not think of a malfunction that would cause this, off the top of my head, but I won't say there's not a 100% chance it couldn't happen, if the circumstances are right.

 

[tddfleming]

The thread above is correct most manufacturers are smart enough to use a downstream design that will result in a freeflow. If you are diving in conditions that are that cold consider a sealed design like the HOG with coldwater kit or the Scubapro MK17. As for the training it is easy to learn and I was also taught this in my OW here in NC in 1995. Instructer was a retired Marine so maybe that had something to do with it.

Not the ex Marine thing My husband is one, when you put a hard headed, opinionated female and a jarhead together, to end up with 2 people that are about to throwdown. Not really, just 2 strong willed personalities clashing.

My inst was most certainly not an ex Marine, but he did teach the free flow in the pool, that is about all the credit I can give him.

 

[JB]

Most modern day regulators are of a downstream design. QUOTE]

I'm not so sure about this! Second stages are generally downstream with the notable exception of some Poseidon models, but first stages are not all downstream. As I understand it "all" balanced diaphragm 1st stages have upstream valves. Since everyone is so convinced they will fail open, perhaps someone could enlighten me as to what design features make them fail open. In theory either of the 2 springs, the HP seat o-ring, the seat itself, or the diaphragm could fail.
I suspect that regs freeze open because during gas flow the temperature drops and freezing occurs in the open state.

 

[tstormdiver]

Most modern day regulators are of a downstream design. QUOTE]

I'm not so sure about this! Second stages are generally downstream with the notable exception of some Poseidon models, but first stages are not all downstream. As I understand it "all" balanced diaphragm 1st stages have upstream valves. Since everyone is so convinced they will fail open, perhaps someone could enlighten me as to what design features make them fail open. In theory either of the 2 springs, the HP seat o-ring, the seat itself, or the diaphragm could fail.
I suspect that regs freeze open because during gas flow the temperature drops and freezing occurs in the open state.

Notice, I said MOST, not all. In a freeze up (icing) conditions most will freeze in the open position.