O-Ring Rupture while Underwater?

[divad]

I’ve seen a couple threads where people mention their tank valve O-ring rupturing at depth. I asked at my LDS and around Haigh Quarry in IL, but nobody has experienced this themselves, and most hadn’t heard of that…

So has anyone here had an O-ring rupture while underwater? If so, what exactly happens? Do you lose all your air in a matter of seconds, or is there enough time for a safe ascent? Can you hear it, or do you notice when your tank is empty? Does the escaping air affect move you around considerably? How does this affect your regulator?

Thanks

If you mean the one between the tank and the valve, yes. It sounded kind of like a small boat. When I got down to the wreck at about 100', I saw that I had used 500#s
of air. I went back up to 50' and the leak seemed to slow down so I hung out a little at 50' then did long safety stops at 20' and 10' just watching the bubbles. I didn't want to waste the air and, yes, I know how stupid that sounds. It gets worse, I had a pony and no real buddies.

 

[rainman_02]

Technically, this is not a ruptured oring. Due to not fully depressurizing or HP air getting under the oring, the air under the oring "pops" the oring out of its home. The pop is often rather loud, and will sometimes send the oring across the room/boat. Often this oring will still be intact after the experience.

Ah. See...I'm still quite new to this diving stuff. Learn something every day!

 

[SDAnderson]

There are a three o-rings associated with most tank valves. One is internal and rarely fails, though it (and the various compression fittings, shims and other internal doo-dads) should periodically be checked by someone who knows what they are doing.

There is a large o-ring between the valve and the tank neck that can fail. This usually happens if the tank is allowed to run completely empty and the valve is loosened in the neck. Failure usually occurs at the fill station, though it can happen after a fill when exposed to heat - like the trunk of your car or in the sun on the dock. Failure is extremely dramatic and can result in a rapidly emptying tank - and colon. Never let all the air out of your tank and this almost can't happen.

There is another o-ring between the valve face and the regulator that can and does frequently fail. On a yoke regulator, this o-ring is located on the face of the valve, on a DIN regulator this o-ring is located on the face of the screw. This failure almost always starts because somebody doesn't fully depressurize the regulator before attempting to remove it from the tank, though the failure often actually occurs when the system is recharged. It can also happen if you don't seat the regulator properly before charging the system. Failure is easy to avoid: check the face before you seat the regulator and make sure the o-ring is in good condition and well seated and then carefully seat the regulator and slowly pressurize the system. Everyone should have a couple of these o-rings in their save-a-dive kit 'cause it isn't unusual for them to go.

 

[Dody]

 

[Marie13]

Felt like resurrecting the dead? Last post was 2005!

 

[Hatul]

Many years ago I was training in a pool and did not tighten the yoke enough. The thing came off and made an incredible scene with bubbling in the pool. The yoke does have to be snug on the valve.

 

[tursiops]

This was reported long ago on The Deco Stop and in Advanced Diver Magazine, and quoted many time since. LHS is late to the party.

Life Ending Seconds ADVANCED DIVER MAGAZINE By Curt Bowen

 

[Dody]

If I was diving locally, I would systematically use a pony but I travel to dive so pony is an hassle. And in many places, you can’t find pony or doubles.

 

[Akimbo]

These two threads might be useful understand O-rings:

Info - O-rings for Divers

1: O-rings for Divers Question: I'm a recreational diver. Why should I care about O-rings? Answer: For starters, an O-ring failure could empty your Scuba tank in about a minute. (Table Reprinted by permission) This table appeared in Life Ending Seconds, 3000 to Zero in 72 Seconds, Advanced...

scubaboard.com

Info - Scuba Cylinder Valve Installation

Scuba Cylinder Valve Installation Very few subjects are more shrouded in diving mystique and folklore than installing Scuba cylinder valves. Casual recreational divers probably don't need to be concerned with this but advanced divers through professionals in the recreational Scuba and...

scubaboard.com

 

[NW Dive Dawg]

I've seen a couple threads where people mention their tank valve O-ring rupturing at depth. I asked at my LDS and around Haigh Quarry in IL, but nobody has experienced this themselves, and most hadn't heard of that.

So has anyone here had an O-ring rupture while underwater? If so, what exactly happens? Do you lose all your air in a matter of seconds, or is there enough time for a safe ascent? Can you hear it, or do you notice when your tank is empty? Does the escaping air affect move you around considerably? How does this affect your regulator?

Thanks

I guess I interpreted the OP's original post as meaning the Valve to Tank O-Ring rather than the Reg to Valve O-Ring. I've never seen or heard of a valve to tank o-ring rupturing or "extruding" at depth. But that definitely doesn't mean that it's never happened.

I do wonder how that might affect overall gas delivery if it were to happen at depth.