Tank oring blew...on surface

[felixtibs]

I know this could of been a lot worse but as I was heading out to a dive I heard a loud hissing noise behind my head. Turns out I was losing air at a rapid speed. luckily my buddy was close and turned of my air. Now I ask you...what would you have done if that happened at sixty feet? Thirty feet?

 

[CuNanoTube]

Surfaced on my pony. I too have had that happen on the surface, I saw the ring extrude. Fortunately I have spares.

 

[Iknee]

I would be pissed off that I had to abort the dive. In either case ascend normally with buddy. Depending on how much air you had and how fast the leak was, prepare to share air and possibly ditch weights. Those who have a pony...

It has never happened to me but I would like to hear from someone who has experienced it. I'm sure it has been discussed on here before, but I remember a similar discussion in the diy about catastrophic failure of your first stage.

 

[Insta-Gator]

I've had that happen once in 20 years. I was floating on the surface waiting on my buddy, so it was just an inconvenience to get out and replace the o-ring. Always remember to stay calm, where it happens.

 

[Blue Sparkle]

Now I ask you...what would you have done if that happened at sixty feet? Thirty feet?

I, too, have had this happen on the boat prior to getting into the water, but not at depth. I think I would proceed similarly whether at 30' or 60'. I'm assuming an OW scenario and a boat dive, since that is my typical dive.

I imagine there would be a lot of noise/bubbles, and I think I would immediately suspect something wrong with my tank valve or first stage. I would get my buddy's attention and have him/her check it out. I'm not sure if I would begin to share buddy's air right away or not -- I'm not sure how quickly gas is lost at depth in this situation. Presuming it's pretty rapid, I would begin to share my buddy's air.

Given how nerve-wracking the noise and bubbles of a free-flow were, I think I would then ask my buddy to shut off my tank valve, to keep the noise and stress down (also, maybe this would keep water out of the tank). (But I'm open to changing my mind on this as others contribute to the thread.)

I think then that we would initiate an ascent, but whether we went directly to the surface or not might depend on the dive site and the state of our gas supply. If there were a fair bit of boat traffic and/or the surface was very choppy, we were not right near the boat, and we had plenty of gas - then I could see continuing to air share and ascending from depth but not all the way to the surface, then continuing to the boat at a shallow depth.

 

[davetowz]

I have never seen one bolw anywhere but on the surface. Has anyone seen or heard of one giving up @ depth?

 

[skankpile]

You say tank, but it sounds like your first stage buldged an oring from a loose connection or pinched ring.

I've had it happen once and ever since then I've double checked my 1st stage hose connections before every dive. I've also almost had a 2nd stage unscrew completely from the hose underwater.. so I religiously check it all before every dive now.

What really got me once was I had a pinched oring on my 1stage between my din screw and body and I heard bubbles underwater... I came up and replaced the ring in there and sure enough it got water in my newly serviced and cleaned 1st stage. It was all torqued to spec so sometimes its just gonna happen and I'm a firm believer in redundancy now on deeper dives.

On side mount if you twist your gauges on the short hp hoses (if not torqued properly) sometimes it has a tendency to unscrew... and you'll hear it when it does as it sounds like a 22 going off near your head.

 

[Blue Sparkle]

You say tank, but it sounds like your first stage buldged an oring from a loose connection or pinched ring.

Although, I did have a tank O-ring blow once and the description sounded similar. In my case I had pressurized my rig (this was in a rack on a boat) and checked it out, then turned it off again. Then just before the dive I re-opened the tank valve, donned my rig, checked it out by breathing off my reg and watching my SPG - all looked fine - and then when I stood up and was about to giant stride off the back of the boat there was a loud hissing sound and the DM said "Oop, O-ring..." I sat back down, changed tanks, and then went on with things. My reg and hoses were fine.

Not saying I know what happened for sure with the OP, but just relating my similar-sounding experience that was the tank O-ring (yoke valve; rental tank).

 

[Bubbletrubble]

What really got me once was I had a pinched oring on my 1stage between my din screw and body and I heard bubbles underwater... I came up and replaced the ring in there and sure enough it got water in my newly serviced and cleaned 1st stage. It was all torqued to spec so sometimes its just gonna happen and I'm a firm believer in redundancy now on deeper dives.

Incorrect installation of the DIN connector can lead to improper seating of that "inner" o-ring and pinching when the part is tightened.
Another possibility is that the wrong sized o-ring was installed at that location.

The "inner" o-ring typically sits in a groove on the connector and, depending on the reg design, the o-ring may stick in there nicely all by itself...or it might sit in there a little loose. If the latter is the case, it's critical to install the DIN connector from below (with the inner o-ring balanced atop the connector) to ensure that the o-ring is seated properly inside the reg when the connector is tightened according to the manufacturer's torque specs.

Overhaul kits come with several o-rings of various sizes so I could also see how the incorrect o-ring might accidentally be installed at that location.

If you service your own regs, you'll understand how easy it is to make one of these two mistakes.
Functional tests conducted during pre-dive checks would give another layer of protection against this.

 

[miketsp]

I have never seen one bolw anywhere but on the surface. Has anyone seen or heard of one giving up @ depth?

Assuming you're not referring to the cylinder neck-ring - failures of those are extremely rare.

I had a first stage o-ring blow at 25m. It sounds like someone is revving a Harley just behind your head.
I stayed on my own reg for a good part of the ascent and then finished the ascent and the safety stop on my buddy's alternate.

Although it sounds and looks very dramatic there was no issue to handle the situation. In my case it took between 1 and 2 minutes to empty the tank from 2/3 full. As long as I didn't have a hard deco obligation I could have easily CESA'd the shortfall.