Show and tell at the ER

[dmaziuk]

Oh, yes. This had to be shared. I'm surprised how that worked, and good to know it can happen.

On a related note a DM on Bonaire once saw me listen for the hiss after attaching the regs and said: don't do that. If the o-ring blows it can blow your eardrum out your nose. If it can blow air bubbles through your skin... :shudder:

 

[Jax]

To be clear, freename, Thank you for sharing this, and thank you for helping to educate others at the ER.

You are a good sport and told a wonderful story. :worship:

 

[illusionistDG]

Did DAN cover the injury?? :wink1:

 

[chillyinCanada]

On a related note a DM on Bonaire once saw me listen for the hiss after attaching the regs and said: don't do that. If the o-ring blows it can blow your eardrum out your nose. If it can blow air bubbles through your skin... :shudder:

Wow.

I do that all the time.

 

[dmaziuk]

Wow.

I do that all the time.

I now put a hand over it and hope it'll provide enough shielding to leave me with just mild barotrauma if it hits the fan. I figure, if I don't hear the hiss through the fingers, the leak is not serious enough to care about. So I might lose a couple of minutes of bottom time, big deal.

Hopefully I'll never get to test that barotrauma theory...

 

[CT-Rich]

I had a burst disk fail on a tank that I had stored at my parent's house. I wasn't there, but they told me they never wanted me to keep a tank there again. I would never approach a leaking tank. There is nothing you can do to fix the problem and there is always the possibility of the situation going from bad to worse (as you found out). I hope you recover from your misadventure quickly, thanks for sharing.

 

[TMHeimer]

freename, How long was your hand in the line of fire? I assume not very long? I use tank air to dry my dust cap, but assume there's no danger to my fingers if everything's working properly. Thanks for the info.

 

[Jim Lapenta]

I tell my students not to use the tank air technique to dry the cap. It can inject water into the first stage if you are not holding it correctly and most of all its annoying as hell to others around you. A towel or tshirt does a better and quieter job.

 

[scagrotto]

I would not have though a leaking tank could put a fine pressure stream out to 'inflate' you hand.

Even if the seal failed instantly around the entire perimeter of the O ring the initial pressure of the escaping air, at some minimal distance, will be tank pressure. Based on the time for the tank to completely empty (or for the leak to become nearly silent) I'll figure the mishap happened when the pressure was perhaps 60% or more of what it was before the leak started. Let's figure 1500psi or so.

I'm sure there's a simple formula for how the pressure decreases. Other than figuring an initial distance from the source, it may be as simple as the inverse square law - at twice the distance the pressure will be reduced to 1/4. That would only apply when the escape path is unobstructed, as any kind of confinement will reduce the rate of pressure decrease. Especially if the leak is limited to a small portion of the O ring I can easily imagine a jet of air with a pressure of a couple hundred psi if you put your hand fairly close to find the source.

Of course, thanks to the OP, we don't need to speculate about it.

 

[jhh]

I'll see your frostbitten hand and raise you some hearing damage:

Previously I had a small car, and had packing it with dive gear down to a science. Everything fit perfectly into plastic bins in the trunk and rear seat, and nothing ever shifted around. Well, I needed more space, and bought an SUV - I never thought about what might happen when things were too loose. So I'm coming back from the FL springs, and round the corner into my driveway just a little too abruptly: The tanks (which had been sitting on their side and held down by a tie strap) fell over, the left post valve caught the wheel of my wheelie bin, rolled on most of the way, blew the dust cover off and through the cover of the rear door. Of course I had the windows up, and by the time I figured out what the hell just happened and got out of the truck my ears were already ringing.

Every neighbor on the street had to come gawk and make fun of me while I just kept yelling "What? I can't hear you!" at them.

Aftermath (with frozen manifold):