XL4+ Setup froze today

[lexvil]

So their description is for the first stage but no discussion of the second, not familiar with this regulator, only aware of it.

Do you know the IP, have you checked it since this happened? Seeing ice inside the mouth piece after the freeflow went one doesn’t surprise me, it may be a symptom not the cause.

 

[CanadaDan]

Since their description is for the entire system I think I can safely assume they are referring to all components as being cold water rated.

I have never checked the IP myself... I have always trusted my LDS and their technicians to check and correct any problems during the annual service.

 

[lexvil]

Since their description is for the entire system I think I can safely assume they are referring to all components as being cold water rated.

I have never checked the IP myself... I have always trusted my LDS and their technicians to check and correct any problems during the annual service.

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I don’t read it that way, they may imply the whole system but specifically only mention the sealing of the first stage, twice. There does seem to be a large heat sink on the second and there is much else they can do there. I would suggest that you get an IP gauge and check it.

 

[Umuntu]

Unfortunately most regulator free flows are due to operator error ...

I doubt the manufacturer can offer anything in the absence of understanding exactly what was done with the regulator during the entire day. Eg. was the purge depressed during setup to test the regulator ? Was the regulator breathed before water entry ?

 

[CanadaDan]

Unfortunately most regulator free flows are due to operator error ...

I doubt the manufacturer can offer anything in the absence of understanding exactly what was done with the regulator during the entire day. Eg. was the purge depressed during setup to test the regulator ? Was the regulator breathed before water entry ?

Only so far as to test the regulator's function and air after swapping the tank. That also would have been at least 15 minutes before entry.

 

[jvanostrand]

I have a few thoughts that might help.

I've seen free flows triggered by a heavy breathing diver when they did a long inflate of their BC. I've also seen it triggered in a calm diver's regs when a panicked diver breathed heavily from his octo. I think when a lot of air is being delivered by a first stage, it delivers colder air to each second stage which raises the risk of free flow.

I've noticed with my Apeks ATX regs that a tightly tuned purge button will free flow a trickle of air in the cold. The test for this is that the purge button activates on the slightest depression. Normally it should activate after about 1 to 2mm of travel. Something in the reg is contracting due to cold and raising the demand lever height until it slightly flows air.

I've often wondered if contaminants, like salt and maybe chlorine can encrust the seat or crown and cause a leaky second stage. It could also offer a better surface for nucleation of ice crystals compared to clean seats and crowns.

Again on a tightly tuned purge button, a rotation of the hose connection may tilt the demand lever slightly, enough to cause a trickle. Normally this can't be done by hand, it requires tools, so it would only happen if the valve spindle nut isn't tight enough. This isn't a loose hose, it's loose nut on the second stage.

A very lightly tuned cracking pressure can cause a slight trickle of air in when you look down. The orientation of the reg and the air column in your mouth is larger than the few inches of water column pressure differential required for cracking.

Of course if any of these things cause a trickle of air, that can easily get worse over the course of a minute or two and turn into a full-blown free flow.

It's not recommended by any recreation agency that I know of, but you can stop a free flow under water. You'd have to breath from a buddy's octo while they shut off your tank. If this is done before enough ice build up in your second stage it only takes a couple minutes to thaw, then you can switch back to your own gas.

I've not done this intentionally, but you can kink your LP hose, like a garden hose, to stop the flow of air. It will weaken your hose, but maybe if bolting to the surface isn't an option damaging a hose is better than breathing water. You unkink it to take a breath, then kink it back again. This is theoretical so experiment at your own risk.

 

[Bigbella]

Possible but unlikely. There were five of us all diving tanks filled at the same shop. My tanks have always been stored with pressure since new.

My question and concern is directed to Apeks as this reg was bought primarily because its stated it was suited for cold water use. I hope they'll post next week and let me know if their definition of cold isn't as Canadian as mine

Any regulator -- "cold water ready" or not -- is capable of freezing up and free-flowing, given the right -- or, more appropriately, wrong -- circumstances. In the future, I would only lightly inhale on the regulator, to test its functioning -- no "Bogarting" either -- before a dive, rather than using the purge button, as had been described above. That could also have been a contributing factor.

I would still suggest that moisture in that air supply was the actual culprit, regardless of what your friends were experiencing, having obtained air-fills, as you had mentioned, from the same station. Not all gear will respond identically. I have witnessed the same thing happen in colder water diving, where one or two regulators anomalously free-flowed, while others functioned perfectly, under the very same circumstances -- fills from the same place; often even the same regulator make, etc. It may also be the specific regulator; its particular settings; your breathing habits, etc . . .

 

[Umuntu]

I would still suggest that moisture in that air supply was the actual culprit, regardless of what your friends were experiencing, having obtained air-fills, as you had mentioned, from the same station.

Given that the free flow only happened on the second dive, I suspect that the second stage had residual internal moisture after the first dive. The second stage free-flowed rather quickly at the beginning of the second dive, which indicates that inadequate care and cold water diving procedures during the surface interval and at the beginning of the second dive were the most likely cause.

 

[CanadaDan]

I heard back from Apeks and they echoed some of the concerns stated here. Primarily the possibility of residual moisture in the primary.

They were also concerned that the settings might have been a little off spec as a result of servicing and resulted in the freeze-up. I will have them re-serviced with the instructions to get back as close as possible to factory spec and try them again.

On the side of user error my venturi setting was also incorrect. I should have set it to the + side after descending. I never do long BCD/Drysuit bursts (every DM gets that reinforced and drilled out of them during training and demonstration practice) but I will endeavour to make sure I indeed only implement properly short bursts. Breathing too heavily may have been an issue but I don't recall anything out of the ordinary during the descent in that regard.

I try them again in a couple of weeks with a good buddy... and a pony bottle

 

[grf88]

It's not recommended by any recreation agency that I know of, but you can stop a free flow under water. You'd have to breath from a buddy's octo while they shut off your tank. If this is done before enough ice build up in your second stage it only takes a couple minutes to thaw, then you can switch back to your own gas.

I've not done this intentionally, but you can kink your LP hose, like a garden hose, to stop the flow of air. It will weaken your hose, but maybe if bolting to the surface isn't an option damaging a hose is better than breathing water. You unkink it to take a breath, then kink it back again. This is theoretical so experiment at your own risk.

Having your buddy turn off your air to thaw the reg should only be done with a buddy pair that have practiced this in shallow conditions and it is suggested that you have a death grip on your buddy's harness while doing this.

Kinking the hose can create a problem if it is a first stage free-flow as it can cause the octo to start free-flowing or in a worst case situation for the inflator hose to free-flow.