When drills become thrills - incident caught on video

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exactly. deep south ..plus the hoses are not rated much past 200 (most of them ) the 2nd stage would over pressue before the inflator would ,if some of these other exsperts knew or had taken reg courses and worked in the industry instead of reading about the mechanics THEY would know that . if glenn did the test ds .....dont wast your time and gas

I agree, but not for the same reason you list.

My experience is very different from what the test presumably proves, and since our lives are dependent on these systems working properly, I'd be very interested in finding out whether or not a separate OPV is actually needed.

If a second stage does NOT act as an OPV, then that means that any HP seat failure (and every one of them eventually fails, just like anything mechanical) could result in a catastrophic explosion or ascent or both. It's actually a pretty big deal for our divers on the job, an potentially life-threatening. Interestingly, this test was supposedly performed on exactly the same brand/model regulator that several of us use, so the test is particularly poignant.

So yes, it's important to find out what the truth is. My experience is that all second stages double as OPVs. If this is false, then my life and all of my diver's lives are at risk.

I don't think that finding out the truth about this myth is a waste of time or gas.
 
The al80 standard pressure is 3000 psi (206 bar) and their actual capacity is 77-78 cuft (~2200 liters) which makes them 11 liter tanks.
Youre correct that the 3l should have about 20 cu ft given a fill pressure of 200 bar (600 l = 21 cuft)

11.1L and 207 bar
 
In the same thread that Phil Ellis posted his findings dannobee posted this. If you follow the links I think you will find some startling information:

"Here's an incident report on IP creep on ATX-200's.

http://groups.yahoo.com/group/ba_diving/message/23351

And the follow up report:

http://groups.yahoo.com/group/ba_diving/message/23440

And another experiment:

http://groups.yahoo.com/group/ba_diving/message/23493

Bottom line, some inflators will bypass with high IP's, some won't. Take your chances.

After we heard this, I think everyone in our little group who has Apeks regs bought IP gauges if they didn't already own them. An OPV wouldn't be a bad idea, but just backing the 2nd stage from fully detuned seemed to allow them to freeflow and obviating the need for an OPV.


Dan"​
 
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In the same thread that Phil Ellis posted his findings dannobee posted this. If you follow the links I think you will find some startling information:

"Here's an incident report on IP creep on ATX-200's.

http://groups.yahoo.com/group/ba_diving/message/23351


It's interesting that, in this report, the diver recommends kinking the hose, and wishes that he had done so rather than ascend to the surface and miss mandatory staged decompression.


I'm really glad you posted this - proves my point. As the author says in the article, second stages are natural OPVs - however, adding a defective/corroded inflator valve with a "all the way tight" second stage, and he got a freeflow into his wing rather than out of his second stage on that post. I am not surprised... I've had an inflator valve leak into a wing before at NORMAL IP. The solution is to fix it. If it happens to you during a dive, then disconnect the power inflator. If you can't do that, then the result is obvious. Notice that none of these solutions include adding an OPV on the first stage - which wouldn't correct a leaking inflator at normal pressure anyway.


Not sure what your point here is, since the power inflator did not vent... But if you were trying to point out that the second stage did not freeflow at 270 psi with the knobs fully detuned, then I am surprised but not wholly shocked. Keep going and yes, it'll vent. And no, nothing's going to explode.

Bottom line, some inflators will bypass with high IP's, some won't. Take your chances.

Chances for what? If your wing begins to self-inflate, then disconnect the LP hose and vent. What's the problem? The fact that he was unable to do this in an emergency situation proves that the problem was that he was unable to do the skill, not that he needed an OPV. In the same way, if your car runs into a telephone pole, the solution would be to learn to use the brakes, not to put a device on the car that limits it's speed to 35 mph.

After we heard this, I think everyone in our little group who has Apeks regs bought IP gauges if they didn't already own them. An OPV wouldn't be a bad idea, but just backing the 2nd stage from fully detuned seemed to allow them to freeflow and obviating the need for an OPV.

...So you found that a certain skill kept you from needing another device. Good for you! My point exactly. :)

Alternatively, this guy would have avoided the accident if:

1. His gear had not been contaminated, and thus not working properly ("pre" option to avoid the issue).
2. As you pointed out, he had not "detuned" his second stage ("skill" option or "technique" option to avoid the issue).
3. He had been able to disconnect his power inflator (first option to deal with issue).
4. He had been able to shut down his right post (a second option to deal with issue).
5. He had kinked his inflator hose (a last option, IMHO - not really "right," but definitely effective).
 
I have never heard before about second stages not free flowing due to increased IP- I thought that was pretty much how they worked. If it is indeed true- every time I am rebuilding my reg, using a second-stage as an OPV, I'm potentially dealing with a bomb?

I was of the understanding that catastrophic HP Seat failure would flood air in to every hose connected to the 1st stage, including the LP hose to the BC.

HP seats, not sealing properly would result in IP creep and a properly adjusted second stage would 'burp' or free-flow.


Another question regarding freeflow. In PADI OW training, students are taught to breathe from the freeflowing reg. What is the reasoning for switching to octopus? To get away from the bubbles which can affect your vision?
 
The only things I think Bill did wrong are:

1 Changing to octopus which wasted some of the air which was leaking out the main anyway - I have easily used a leaking main till the tank was empty, gave me a minute or two more air that I would have had otherwise

2 Not ascending a bit quicker (but still within safe ascent rates), they were only at 15 m and only down a few minutes

3 Doing a safety stop (for same reasons as 2)

4 Shining torch in buddy's eyes, I saw this at least a couple of times

Otherwise, they both stayed calm, and this is very important.
 
i belive deep south is right , in so many ways .. the first being lack of skill in the emergency , my open water students learn to disconect the bc lp hose if it starts to fill uncontrolably. 2 in over 30 years activly teaching and 40 + years diving i have never seen a bc start to auto fill (doesnt mean it cant happen) but the type of ip pressures they talk about i find HIGHLY suspect that a lp seat would hold back that type of pressure and op the bc mech , 3rd if you get your equipment serviced by a properly trained tech this kind of situation could be either reduced to almost a nill possibility..(but nothing is a100 % in this world of mechanical devices )
 
I am shocked !!!, what a mess. Again this ; octopus/ bcd /hamburger agencies/plastic clips and shiny computers /card collecting/ specialty and course director ultimate goal dive culture/everyone should be diving and buying kit culture....bbrrrr
The only thing I liked was the cool attitude of the diver !
A great example what is wrong in the diving community....

I Can't believe it...you really think you were going to get yourself bent? after these 4 minutes ??
It is time that people stand up and demand proper training from well trained instructors...no more hamburgers...
 
This entire dive is a CF - <snip>
Although viz was low on this dive it is by no means the worst that can be had and low viz to no viz comm should be second nature to dive leaders if those are the normal local conditions. If these are normal local conditions, in your OP you said that viz was better than normal, hopefully for leadership level divers these conditions would not be all that challenging. If you find that these conditions are very challenging or to challenging to handle what should have been a simple call the dive and go up when problems developed you are not ready for leadership level diving locally.
I do not know about others but I do not need to see a free flow to know it is happening- I can hear it. A free flow is pretty noisy and an attentive buddy should pick that up almost immediately.

While I agree with the CF analysis - viz looked fairly good. Given OPs statement that viz was better than normal, I'd say replacing with the rope with a safer straight line should be a very high priority.

Japan-diver - do you dive wearing a hood? For me even a 3mil hood significantly reduces my hearing. A 5-7mil as these divers was wearing effectively makes them deaf.

To those denigrating maintaining physical contact with the line - I occasionally dive in conditions where you can lose the line when it's less than 1' from your face. Been there / done that. Now do you do abort and do a free ascent or descend hoping to find where-ever the line is leading you?

To OP - don't complain about the dark. The dark is your friend. Quite often viz is considerably worse near the surface where sun through silt creates a bright white fog which obliterates any light I carry. Once out of the sun zone I personally can see far better even when the water is still silty. FWIW: My diving is often in conditions in which your friend would not have been visible at the large separations you had. Every dive is solo no matter who your buddy is!
 
https://www.shearwater.com/products/swift/

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