free-flow - what to do?

[Crush]

A few recent threads have dealt with free-flow, either free-flow which occurred, or is speculated to have lead to an accident to which there were no witnesses. It seems that, in some cases, diver's don't react properly to a free-flow.

What do you recommend, other than the obvious items such as making sure you have a cold-water reg and ensuring that your air supplier does an extra good job ensuring dry air fills during the cold months?

My previously-posted suggestions follow. Constructive criticisms are welcome:

The simplest solution to a free-flow is to immediately thumb the dive and keeping the free-flowing reg in your mouth make a normal ascent to the surface. If you caught the free-flow while it was still a trickle and you are not gushing air rapidly, watch your pressure - you may have enough air to do a safety stop. However, do not risk going OOA - a safety stop is not mandatory if you have not gone into deco. There is absolutely no reason to stop breathing off the free-flowing reg unless you are diving doubles with an isolation manifold and want to switch regs, isolate the free-flowing reg, and swish it about the water for a minute so as to melt the ice crystal (assuming a 2nd stage freeze-up). You can of course follow the same procedure using a buddy's octo (i.e., turn off your tank and swish your reg about in the water while breathing off an octo), but you run a real risk of causing his/her gear to free-flow as well owing to the larger demand for air.

Once you start breathing off someone's octo in cold water at depth you more than double flow through the first stage regulator (owing to rapid respiration since you are panicked). The air, which is normally cold exiting the first stage, is now even colder. The second pressure drop at the second stages allows even more cooling to occur. Ice crystal formation becomes increasingly likely at each step.

 

[knowone]

Work on your own stuff.

Fold your hose in half.

 

[Garrobo]

What knowone said plus there is a shutoff valve which you can buy which installs on your hose where it connects to the reg. Of course you would surely want an octo or other means of air supply to back you up. Or you could breath off of the flow till you got to the surface. Lots of remedies available.

 

[lowviz]

...........Or you could breath off of the flow till you got to the surface. Lots of remedies available.

I use an H-valve just so I can swap between doubles and a 'last-dive single' without reconfiguring my regs on the boat. (another thread) This gives me the option of shutting off the offending post and letting the primary and secondary regs warm up. Truth is, I'd probably just head up. A free-flow should never be a crisis and from personal experience they tend to start slowly before they get violent. Looks amazing under water, isn't a big deal if you dive rock bottom rules. I'm with Garrobo, dive over.

 

[irishsquid]

Sounds like most has been covered already. Maybe give thanks it isn't a "no flow".

 

[Blackwood]

Buddy's air
Feather the valve
Fold the hose

 

[Bubbletrubble]

What about making sure that the Venturi lever is set to the "pre-dive" or (-) position?

 

[flots am]

Fold your hose in half.

Freeflows in cold water are caused by ice in the first stage which causes the IP to rise far above what the second stage can hold back.

Folding your hose will only give you a damaged hose and a free-flowing alternate second stage

If you need to stay down (deco, etc.) the only solution is to turn off the tank valve feeding the free-flowing reg and let it thaw, while breathing from something else. This can be another tank you brought or your buddy's alternate. However you should note that the added load may cause your buddy's first stage to free-flow.

If you don't need to stay down, you can simply ascend with your buddy and breathe from your free-flowing reg. It's only annoying, not dangerous and won't "force air into your lungs" (the exhaust valve has a higher maximum flow rate than the inlet).

Depending on your depth and tank pressure, it may last until you get to the surface, but you definitely want to have your buddy along in case it doesn't, and you can't power inflate and forget to manually inflate or ditch weights.

If you have a free-flow in warm water it means you're either diving into current that your reg wasn't designed to handle, or need a new service technician, or think routine maintenance is for "other people." In any case, you can still surface with your buddy, as above.

flots.

 

[mizzie]

This may be a stupid thing to say, but I'm not yet certified (not even in classes, just doing the book work right now) and have obviously never had this problem. But what I was told to do in the case of a free flowing reg was to take it out of your mouth, or mostly out (with just one side in), hold it to your lips and sort of "sip" the air. I guess this is to prevent the reg from popping out of your mouth? I was also told to immediately end the dive, since a free flowing reg will burn through your air like crazy.

 

[Erku]

This may be a stupid thing to say, but I'm not yet certified (not even in classes, just doing the book work right now) and have obviously never had this problem. But what I was told to do in the case of a free flowing reg was to take it out of your mouth, or mostly out (with just one side in), hold it to your lips and sort of "sip" the air. I guess this is to prevent the reg from popping out of your mouth? I was also told to immediately end the dive, since a free flowing reg will burn through your air like crazy.

That's what I was taught too. I'm not clear on the reason for the half-in-your-mouth thing rather than just leaving the reg in; it didn't occur to me that I could leave the reg all the way in, so it didn't occur to me to ask.