Free Flow Question?

[Sean C]

Please indulge me. I know how to breath from a free flowing reg. and actually practice the skill with my wife at regular intervals. But, I have no idea what it is like to have a reg free flow at depth while in use, ie. not simulated.

Aside from the momentary shock, what the hell happens and in what sequence? Does the reg almost get pushed out of your mouth? Do you get any kind of warning (increased pressure/flow that you notice)? Do you get a blast of air into your lungs? Honestly, I hate practicing this drill, I played too much hockey and this drill freezes the caps !!!

I could simulate what this is like by hitting the purge, but we were told not to do this when the reg is fully in your mouth and if I initiated the free flow it would be simulated not spontaneous.

Any insight, would be greatly appreciated.

Sean

 

[Rick Inman]

Please indulge me. I know how to breath from a free flowing reg. and actually practice the skill with my wife at regular intervals. But, I have no idea what it is like to have a reg free flow at depth while in use, ie. not simulated.

Aside from the momentary shock, what the hell happens and in what sequence? Does the reg almost get pushed out of your mouth? Do you get any kind of warning (increased pressure/flow that you notice)? Do you get a blast of air into your lungs? Honestly, I hate practicing this drill, I played too much hockey and this drill freezes the caps !!!

I could simulate what this is like by hitting the purge, but we were told not to do this when the reg is fully in your mouth and if I initiated the free flow it would be simulated not spontaneous.

Any insight, would be greatly appreciated.

Sean

Hi Sean!
Lots of old threads on this, if you want to do a search.
I've had several free flows in very cold water. We plan for these, go to Bkup air, turn off the valve, let the ice melt, turn back on and continue the dive. But as I got better at cold water diving, the free flows virtually stopped.
At least in cold water freeze ups, you can often feel them coming. There's a couple of breaths of slow bubbling, which increase with each breath, and then finally free flow. It's not that big of thing to deal with if you don't freak out about it. Obviously, you're going to have an empty tank soon (how soon, is also the subject of many past threads), and so it's time to call the dive. Although PADI teaches you to hold the regulator part way out of your mouth, I find that, if you do it right, you can leave it in and use your tongue to slow the flow into your lungs. (However, I also own a Poseidon that has higher pressure at the 2nd stage, and if that baby goes, you're gonna' want it OUT of your mouth)
If you're more comfortable, go immediately to your buddies bkup air and enjoy the ride home. Or, breath off yours - keeping a good eye on SPG - until you get low, and then switch.
This is one of the easier issues to deal with, and I don't remember ever hearing about a death due to free flow.

So, except for some rare cataclysmic regulator failure, I don't believe you have to worry about taking a breath and then suddenly having 3000PSI of air blasting into your lungs.

Disclaimer: the above was only my opinion, and I am sure to be wrong.

 

[Sean C]

Thanks Rick, I just wanted to know what to expect.

Sean

 

[Rick Inman]

Thanks Rick, I just wanted to know what to expect.

Sean

Do the search and read what others have to say. You'll be glad you did!

 

[FreeFloat]

All my dives to this point have been in cold fresh water (down to 31.5°F) over winter so I feel my experience with Freeflows may be of some use to you.

Thanks to an older rental reg, I had several freeflows in rather short order over the course of a few dives this winter. While YMMV, what I noticed was: first the reg would begin to "hiss" very softly after I stopped inhaling - this was a sign it was no longer closing fully. On each inhale the "hiss" would get longer. When the thing kicked into full FF status I noticed a continuous flurry of bubbles and yes I sort of did notice the stream of air. Most of it escaped out the reg's vent and in fact as the freeflow progressed I found I had to "draw" or "suck" my share of the air out of the reg (did I happen to mention these were very low-quality rental regs?) Although I had practiced "simulated" freeflows during training as well I found the "real thing" to bear little resemblance to the holding-in-purge-button flows. However it was a relief to discover that no, it does NOT feel as if the reg is trying to inflate my lungs (at least it didn't for me, although that could have been due to the low quality of the regs to begin with)

 

[Sean C]

Thanks FreeFloat, your description was exactly what I was looking for.

 

[Cudabait]

Please indulge me. I know how to breath from a free flowing reg. and actually practice the skill with my wife at regular intervals. But, I have no idea what it is like to have a reg free flow at depth while in use, ie. not simulated.

Aside from the momentary shock, what the hell happens and in what sequence? Does the reg almost get pushed out of your mouth? Do you get any kind of warning (increased pressure/flow that you notice)? Do you get a blast of air into your lungs? Honestly, I hate practicing this drill, I played too much hockey and this drill freezes the caps !!!

I could simulate what this is like by hitting the purge, but we were told not to do this when the reg is fully in your mouth and if I initiated the free flow it would be simulated not spontaneous.

Any insight, would be greatly appreciated.

Sean

Sean,

Inman pretty well sumed it up and pointed you in the right direction. The following is what I've experienced over the years: Two free flowing secondaries caused by problems which materialized with the second stage during dives. One began with a slow flow of gas which quickly increased to full freeflow. The other was instant freeflow.

Blown high pressure seat in first stage: This is a little more dramatic and you would have to take air from a freeflowing reg until you get some air from another diver or surface. Usually, when a high pressure seat blows you will hear a "thump" sound immediately followed by freeflow thru both of your primary and secondary regs. (Octo) This can be very serious at depth, particularly if you are relatively low on air when it happens. Freeflow breathing is a must and you'll have to surface immediately if you cannot quickly get to an alternate source of gas.

I have experienced this once, and was also in a group when a videoagrapher blew a high pressure seat. He made a freeflowing ascent from a depth of about 60'. He did not experience any problems.

These were all warm water incidences.

This is just one of many reasons for equipment redundancy when participating in certain diving activities.


Regards,

 

[JDostal]

I've had two free flows with similar results as everyone else here.

You'll be doing great, breathing as normal - and you'll start noticing something amiss - all of a sudden, the reg breathes extremely easy - it's almost as if it's pushing the air out, every so gently. It's like it's trying to feed you the air, instead of you pulling the air from it.

A few breaths later, you'll stop your inhale and the reg is still bubbling - ie, you are not taking any more air into your lungs, but air is still coming out of the reg and going out the exhaust. Not bad at first, maybe it's just a little slow to trail off on the end of your inhale.

This will slowly get worse. You'll take a breath (and by now, the air coming in will be a little more forceful) and the reg won't stop doling out air for a few seconds after you stop inhaling.

Eventually, it will just keep flowing. Nothing too bad at first...but it's a constant, never ending flow of air. The reg is now officially free-flowing. It's slow and not too bad at first, and it may stay that way. The two that I had kept getting worse and worse until it was pretty much the same as holding down the purge button. That's when your practice comes in handy

It's not too bad of a deal - the first two times it happened I was new and wasn't sure how to deal with it so I surfaced.

Now, with redundant regulators I've practiced shutdown sequences and probably wouldn't let a free flow end my dive.