Emergency inflator hose breathing

[oldflounder]

I read this in Scubaboard Articles_Scuba Skills_Intermediate and Advanced Scuba Skills_Choosing the BCD You Need by John Adsit

[Some BCDs replace the normal low pressure inflator hose with one that also serves as an alternate air source. While all low pressure inflators can be used for air in an emergency, some designs incorporate a fully functioning regulator. In an out of air emergency, the donor gives the buddy the primary second stage and then uses the regulator on the low pressure inflator. Since many or most out of air emergencies are signaled when your buddy yanks the regulator from your mouth, this is a convenient way to go on breathing, and it has the advantage of eliminating an entangling hose from your regulator setup. Although this comes standard in some BCD designs, it can be added separately to most BCDs.]
What caught my eye, and what I have wondered about in the past, is this portion"While all low pressure inflators can be used for air in an out of air emergency" I have done a search here but I can't find any answer quickly.

I have read in an OOA you can suck off any excess air in your bladder in an emergency ascent because it will expand as you rise.

Supposing you had an issue with a malfunctioning primary and you didn't have an octo [stupid I know] or your hoses were cut by the bad guys, could you breath off your inflator mouthpiece by mainipulating the inflation button and release buttons? Would the pressure on your chest, at let's say 80', be too great on your chest to allow you to breath in without a primary regulator.

 

[boulderjohn]

I wrote that article long ago. It contains material I no longer believe to be true. This is one example. I frankly wish the whole thing would go away.

 

[Bubbletrubble]

Would the pressure on your chest, at let's say 80', be too great on your chest to allow you to breath in without a primary regulator.

At what pressure (relative to ambient) is gas delivered to the power inflater mouthpiece, assuming that the inflater button and exhaust button are depressed simultaneously (and the mouthpiece is at the highest point of the BCD in the water column)?

 

[Dr Wu]

Sure it's possible.

Go to Frogkick.nl - De Online Gids voor DIR Duiken - Doing It Right Duiken

Click Bibliotheek

Click Ademen uit inflator

Enjoy

Oh, and it is not necessarily stupid to dive with no octopus or other alternate second stage.

 

[oldflounder]

I am thinking the pressure is at 125-160 in the low pressure hose at any depth - is that right. Then the primary reduces that pressure to breathable ambient at whatever depth you are in the water column. I am assuming the button mainpulation if possible would cause a free-flow type of pressure release - at 125# - but still breathable. [I know your chest does not feel the pressure of the surrounding water if anyone is going to catch me on that one.]

 

[Bubbletrubble]

Yeah. That's basically it. The first stage steps the high pressure tank gas down to 125 - 160 psi (whatever the IP is set for) above ambient. The second stage functions as a demand valve.

 

[oldflounder]

Sorry for the stupid comment. I was trying to be sarcastic. There are those out there that would flame me for saying you don't need an octo for your buddy or some other secondary such as one on your inflator hose.

 

[spectrum]

When you hold the inflate and deflate buttons sumiltaneously you will get air release. You need to be sure that a portion of it is not inflating the BC and starting a runaway ascent. You can run out of hands real fast here.

Once the IP air exits the valve it expands and is at ambient pressure. As long as you sip the flow so you are catching the bubble stream it will be ambient in pressure. If you were to latch onto it with a seal then you will experience something close to ambient until the BC inflates fully. At that point you lungs or the OPV valve will give way.

Pete

 

[Bubbletrubble]

When you hold the inflate and deflate buttons sumiltaneously you will get air release. You need to be sure that a portion of it is not inflating the BC and starting a runaway ascent. You can run out of hands real fast here.

@spectrum: Wouldn't rolling onto your back and sipping off of the power inflater mouthpiece work? This would place the mouthpiece at the highest point in the water column. Gas should be exiting without filling the BCD bladder. No extra hands needed (so long as you could maintain this position).

 

[psiborg1812]

PRACTICE THIS IN THE POOL FIRST!!

It is totally possible, however, it is tricky to say the least. For one thing, you will be inhaling the air slower than it is being delivered, so your bc will expand unless you suck out the excess air after releasing the inflate button. One thing that was taught me was that if you have to do this skill, then keep the deflate button depressed and fin your way to the surface, while taking breaths using the inflate button as needed, that way you can control your ascent.