Strategies if an o-ring pops at depth

[BuoyantC]

Glad to see someone point out the bad practice rotating valves after the air is on. Seems almost all new divers do this and shred the o-ring surface.

As for yoke mounts, there is nothing inherently bad about them. All emergency O2 kits I've seen use yokes. Admittedly the DIN with it's higher pressure potential is a better, more compact design, but BOTH styles rely on o-rings.

My wife had a DIN o-ring failure at the surface while teaching in a pool, and it had been pressurized for a while. Having never seen a DIN o-ring fail, this one was who knows how old. Good idea to inspect them or just change them periodically.

And for String's comment about DINs being near universal outside the US...who is he kidding. If you travel with a yoke valve, you will not have a problem anywhere except perhaps wherever it is he lives.

 

[BuoyantC]

sorry for double post....#$%! internet connection.

 

[Lone Frogman]

Hi,
This may have been asked (many times) before, if so, please point me in the direction of any link appropriate.

On a recent liveabord trip we had lots of blown tank o-rings on the boat or zodiac. PITA but no dig deal.

However, had one blown at depth this would probably change the PITA to something different.

I've never had an o-ring blow whilst underwater. Can anyone with more knowledge advise whether the symptoms are catastrophic (in terms of gas loss) as I can't imagine air would be delivered to the second stage. In which case I'm guessing getting to a buddy sharpish or CESA would be the only options?

Or are there other aletrnatives?

Apologies if the question seems basic but I guess this would be the right forum.

J

Grab regulator on pony, turn on pony and breath normally. Abort dive and return to surface.

 

[Tigerman]

Hi,
This may have been asked (many times) before, if so, please point me in the direction of any link appropriate.

On a recent liveabord trip we had lots of blown tank o-rings on the boat or zodiac. PITA but no dig deal.

However, had one blown at depth this would probably change the PITA to something different.

I've never had an o-ring blow whilst underwater. Can anyone with more knowledge advise whether the symptoms are catastrophic (in terms of gas loss) as I can't imagine air would be delivered to the second stage. In which case I'm guessing getting to a buddy sharpish or CESA would be the only options?

Or are there other aletrnatives?

Apologies if the question seems basic but I guess this would be the right forum.

J

I actually had this very thing happen in august and the answer to me got crystal clear when we where back on the boat and we had a little "debrief" on what happened..

We jumped in for some manta ray action, followed it for a few minutes and ended up at around 20m (65 ft). When I look back at my buddy I think shes having a way big exhale, then she turns around looking at the weird sound coming from behind her and I realize theres a REAL major leak from her tank, so I get closer to her and offer my octo. She didnt realize what was going on as she couldnt see the bubbles and thought it was a speedboat or something, so I signaled for her to stop, look at her pressure gague and take my octo before I shut down her tank valve and we started to get closer to the reef and ascend (we where quite far from the reef out in the blue).
We never got stressed or anything, so from that point of view it was just a perfect air-share ascend drill.
My buddy was a small woman that usually use about half the air I currently do and I came up with 30 bar/435 psi less than I jumped in with, she had used 80 bar/1160 psi. Probably 70 bar/1015 psi of that was lost in a matter of a couple of minutes.
Total dive time was 10 minutes.
This WAS a badly blown o-ring, but it was a matter of a minute or two to take out almost half of her air.

What I learned from this was pretty much that I will do the EXACT same thing if It happens again.

Donate an alternate air source, shut down the freeflowing tank and abort the dive safely (in that order).
If theres doubles or multiple tanks in other configurations it may be different, but for single tank dives, just get an alternate air source and abort the dive ASAP.

 

[Gilldiver]

A "rash" of O-ring's going is a sign of either someone putting the regs on wrong for you, was this a place the crew set up your equipment? Or, they had a batch of soft O-rings.

As for the O-ring going, I would not care about the tank getting any water. I will keep on the tank untill I either run low or reach the surface. Only if running low - less then 300-500 psi - will I go onto anothers tank or pony. This keeps the majority of usable gas being used for life support. This may become a big factor at near or into DECO range.

Also, if you hear a a loud noise from behind your head, do a quick roll, look up, and see if a lot of bubbles are going up, if they are then you know that you have either a HP hose, LP hose, tank or reg O-ring gone. End the dive and do a controled accent to the surface or to your deco stop etc.

 

[Tigerman]

There was no "rash" of o-rings blowing. It was one o-ring that blew at depth (yoke o-ring) and the surface air temp was ~40c/150f.

Pretty much the only other o-ring blowouts ive seen at that place in 3 weeks of diving has been people who checked their air and forgot to shut down the tank and get the pressure out of their hoses with the result that rings blow because of the air expanding in the anything but cool temprature..

 

[Gilldiver]

The part where it is stated:

On a recent liveabord trip we had lots of blown tank o-rings on the boat or zodiac.

One O-ring going is chance, 2 is strange coincidence, "lots of" indicates other factors and is a bad rash to me.

 

[TSandM]

When I have an emergency, my training is, first and formost, to "go to the surface". Go straight to the surface. Do not hesitate. Do not think about "how" to fix the problem. Do not dawdle. Start you asscent immediately.

This is probably a reasonable approach for shallow dives, but as you get deeper, or get into different diving environments, there are situations where a direct ascent without thinking may not be the best answer at all. You may lose the boat in current; you may end up in very bad surface conditions, or in a shipping lane. In the described situation (blown o-ring) you may not have enough gas to get to the surface in a controlled fashion from the depth where you are, before the tank runs out. I firmly believe that it is ALWAYS better to think, than to execute a knee-jerk response. Immediate ascent may be the result of your brief pause to think, or it may not be.

 

[InTheDrink]

One O-ring going is chance, 2 is strange coincidence, "lots of" indicates other factors and is a bad rash to me.

Indeed, it a veritable rash of bad o-rings. Guide blamed cheap local o-rings, I wasn't completely convinced.

Initially my buddy and I thought it was divers assembling their gear wrong as it seemed limited to a few of the less experienced divers. However, as the week progressed and as it happened to pretty much everyone on at least one occasion it became pretty obvious that it wasn't diver error - just crap/old o-rings. It was a bit disconcerting but more annoying and time wasting than anything else.

It was funny how we attributed the issue to human error until it started happening to us. Is it called classic misappropriation theory or something? In any event, I'll be slower to rush to judgement in the future.

J

 

[Tigerman]

The part where it is stated:



One O-ring going is chance, 2 is strange coincidence, "lots of" indicates other factors and is a bad rash to me.

Ahh, my bad.
Could be as simple as the air being hot and people not knowing/remembering/bothering to shut off the tank and de-pressurize the hoses after checking the tank pressure and leaving the tank ready for a while or it could be a more "deep rooted" issue like bad maintenance or wrongful setup..

This is probably a reasonable approach for shallow dives, but as you get deeper, or get into different diving environments, there are situations where a direct ascent without thinking may not be the best answer at all. You may lose the boat in current; you may end up in very bad surface conditions, or in a shipping lane. In the described situation (blown o-ring) you may not have enough gas to get to the surface in a controlled fashion from the depth where you are, before the tank runs out. I firmly believe that it is ALWAYS better to think, than to execute a knee-jerk response. Immediate ascent may be the result of your brief pause to think, or it may not be.

As this was the third day we did that day, I really didnt want to just go to the surface and skip the safety stop.
Her tank probably would have had (only just) enough air for it, but then again there was a few different issues with that at the location we where on.
There was the fact that we had done 3 dives a day for a few days, most of them by rec standards "deep" and there was also lots of boat traffic so as long as we could do it safely I just found it better to use the time to get closer to the reef and ascend slowly and getting a safety stop in on our way a better option.

The guys that opted NOT to do the third dive actually got a lot more stressed than we did cause they saw the crazy ammount of bubbles, a saucage popping to the surface and people coming up sharing air and stuff