Well, O-rings do just explode.

[BarryNL]

That was an eye opener - this morning I'd hooked a regulator up to a tank here to test a BCD power inflator I'd serviced and I'd left the regulator on the tank and forgotten about it.

This evening I'm sitting here watching TV and there's an almighty hissing suddenly coming from the hall - my tank is suddenly rapidly losing air. The second O-ring behind the DIN/INT adapter in the tank valve had suddenly decided to split with the expected violent loss of gas.

A very good reason to practice valve shutdowns and air-shares! This can happen - luckily this time not underwater.

 

[Rick Inman]

I was the video guy for a trimix class last summer, which took place at a campground on a nice lake. We dragged HE, O2 and argon bottles to the site and blended right in the campground. Between the four of us and stages and doubles, there were more than 40 tanks. With the gear to with it, that's a lot of O rings.

The air temperature was in the nineties, and the bottom water temp in the upper 40's.

We lost O rings several times during that class and were surprised we didn't lose more. But with good maintenance and good pre-dive checks, we never lost even one during a dive.

 

[300bar]

Just go DIN,and skip that never ever checked inner O-ring on a yoke valve.
You state youre a dir practinioner/wannabee,so what's with the yoke anyway.

 

[JohnnyH]

We lose yoke valve face o-rings all the time where I work - very annoying. We do five dives a day and the regs see heavy service. I find that the most common culprit is the flat surface on the yoke that mates up against the tank valve. Sometimes that face gets rounded from long service (read "abuse") and the o-ring can extrude, so I end up replacing this component on the regs.

For personal diving I dive DIN.

FWIW

John

 

[BarryNL]

Just go DIN,and skip that never ever checked inner O-ring on a yoke valve.
You state youre a dir practinioner/wannabee,so what's with the yoke anyway.

I have an INT set as well which I use when working with students. They tend to get a bit confused if you show up with something different to what they're using.

 

[String]

Similar issue here. My regs are DIN but the other 65 members of the club are all A-clamp.
It does however mean they can't steal my tank or regs.

DIN o-rings can still go - i've had it happen once however the rate of gas loss is much much slower than with an A-clamp o-ring failure.

 

[Lead_carrier]

Just go DIN,and skip that never ever checked inner O-ring on a yoke valve.
You state youre a dir practinioner/wannabee,so what's with the yoke anyway.

Barry said..The second O-ring behind the DIN/INT adapter in the tank valve had suddenly decided to split with the expected violent loss of gas.

According to what I read in his statement, it was a DIN o-ring that went. And they will go. Usually for the same reason that yoke o-rings fail. There's definitely a lot more yoke failures but then again, there's probably a lot more yokes. But if your inner o-ring is never checked, find a different serve tech. That should be checked at every rebuild.

 

[String]

Checking prior to setting the kit up is more sane. It takes 5 seconds to inspect an O-ring.

 

[Teamcasa]

....A very good reason to practice valve shutdowns and air-shares! This can happen - luckily this time not underwater.

DIN or Yoke, I think Barry's point was to turn off the valve(s) if it is not going to be used promptly. Good advice.

 

[drbill]

Agree on turning off the valves. This is one reason I dive DIN... I'd hate to have an o-ring blow at 200 ft even though I have backup. Hmmm, I've never had an o-ring go on my pony which has a yoke valve on it. Of course we do see them blow occasionally on the boat since there are about 50 tanks there, almost all yoke.