Need advice on how to handle possible O-ring failure at depth

[Bubbletrubble]

One point that I think should be mentioned...

A small consistent stream of bubbles coming from the vicinity of the reg first stage doesn't necessarily mean that the yoke tank valve o-ring requires replacement or that something is wrong with the regulator.

There is at least one brand/model of reg (Sherwood Brut) for which it is entirely normal to have a small stream of bubbles leaking out from the ambient chamber of the first stage. This leak occurs due to a one-way bleed valve intentionally designed by the manufacturer.

 

[cloudflint]

Switching the tank on, then switching it off and leaving it for 5-10 minutes ive found works great for detecting any leaks. For signalling bubbles I generally kinda wiggle my fingers and move my hand up and down a few inches. So on the odd time when ive had to tell someone their tank valve is leaking a bit, i point to them (your), then my tank valve (tank valve), then do the wiggly fingers up and down (bubbling)

 

[blue steal]

One point that I think should be mentioned...

A small consistent stream of bubbles coming from the vicinity of the reg first stage doesn't necessarily mean that the yoke tank valve o-ring requires replacement or that something is wrong with the regulator.

There is at least one brand/model of reg (Sherwood Brut) for which it is entirely normal to have a small stream of bubbles leaking out from the ambient chamber of the first stage. This leak occurs due to a one-way bleed valve intentionally designed by the manufacturer.

Noticed this on my first trip to Cozumel. At the resort I was staying they were renting sherwood bruts.

 

[Juardis]

Some additional info.

re: size of air leak. Turns out it wasn't that big as she had same amount of air as I did at the end of the dive. But the experienced diver holding her spare regulator ready to offer to my wife at a moment's notice had me a little worried. Yes, we were taught how to air share, but that doesn't mean we want to do it, so to us, it IS a big deal. I like the suggestion to practice it until it becomes boring though.

re: seating. When we got to the surface, we removed her reg, then reseated it. Leak. it's a brand new regulator, but just in case, we used one of their regs and it was the same. So it wasn't an improperly seated regulator.

re: buddy distance. Yes, that's one of the things we need to work on. The next day we actually held hands for awhile just to make sure we were close enough.

re: doing bubble checks. Agreed, it's been added to our checklist since this incident. But we do listen for leaks on the boat and didn't hear one, at least at the dock. We didn't listen after she reattached her reg to that tank in preparation for our second dive. Didn't think we needed to since it was OK at the dock. It, too, has been added to our pre-dive checklist.

So what we agreed to do. Do the leak listen test after attaching our regs. Do a bubble check after descending. If either tank develops a leak, let the other person know. Monitor SPG more frequently if there is a leak and stay within hand holding distance at all times. That's what we decided on anyway.

Thanks for all the advice and operating experience.

 

[temet vince]

When I got my open water cert, it was not uncommon at all to see leaky tanks. I'd say maybe 25% of our tanks leaked bubbles. Not a big deal, unless it's a ton of bubbles. Small leak isn't much to worry about.

 

[Reef_Haven]

A lot of boats have a small spray bottle of liquid soap and water for defog. A small squirt can be used to easily determine exactly where the leak is located.

 

[temet vince]

Another thing to think about is that small leaks won't run you out of air like crazy. I don't think a bubble leak increases the amount of air leaving the tank at a deeper depth, unlike your regulator.

I'm new at diving, and so I'm an air hog. So thinking that just by breathing a bit at depth causes my air to run out would make a leak seem bad. But that's just because you're breathing compressed air. A little leak won't destroy your bottom time.

It's still unnerving though till you get used to it.

 

[Quero]

One point that hasn't been touched on is the "what if" question:

... what would I do if I suddenly discovered a turbulent stream of bubbles hitting me in the back of my head and then being out of air. Would I know what was happening? (maybe) Would I freak out? (possibly).

This happened to me one time. Since you are prone in the water, you don't actually feel bubbles striking your head (they rise in the water column above and behind you). What you notice is a lot of noise. Escaping air is very noisy, so you are surprised by this, and you look around to find out what's causing it--but you can't immediately identify the source, since you can't see what's happening behind your own head. Other people also hear the racket, and of course they can actually see that it's coming from you. Somebody will immediately swim up to you and extend an AAS. It won't be long before they are able to communicate (with the waggling finger thing), that you are having an o-ring failure. However, even at this point you are sort of confused about the whole episode because you are able to breathe perfectly normally. You are not suddenly out of air. It takes quite some time--minutes (which in an emergency situation seem like hours)--for the tank to empty, and it's actually more than enough time to put emergency procedures into action, calmly, without freaking out. I'm not saying to ignore a faulty o-ring, but I am hoping to let you know that while a blown o-ring is an honest-to-god emergency (unlike a minor bubble stream escaping from the first stage connection), it's not something worthy of freaking out about. In fact, freaking out could quite possibly cause an injury due to a too-fast ascent or some other panicked action, whereas a calm switch to another diver's AAS would allow for a slow and safe ascent. I'm just hoping to fill in the blanks about what might happen in case of complete failure due to a blown o-ring; it might help you put things in perspective in terms of what the more experienced diver did in trying to help.

 

[keyshunter]

Leaking valve o-rings on yoke connected tanks are not at all uncommon. Probably 25% of the rental tanks I use have slight valve o-ring leaks. To detect an o-ring leak when gearing up, I use the method of pressurising the reg, and then turning off the tank and watching the pressure gauge. If the pressure drops rapidly, I change the o-ring, if it drops very slowly, I don't worry about it for normal RECREATIONAL dives. Usually the actual gas loss during a dive is very slight, but experience is important here. Of course, to use this method, one must be sure that there is no leak elsewhere in the gear. In my experience, if an o-ring is going to blow it happens at or near the beginning of a dive when tank pressure is greatest. And, a slight valve o-ring leak usually diminishes as the dive progresses and tank pressure decreases. But, if one hears a leak when underwater, (unless one is stone deaf, it is difficult NOT to hear a leak) it is prudent to be extra vigilant with pressure monitoring. Older style Sherwood regs (Brut. Magnum. Oasis, Blizzard) use a dry bleed system which releases a very small but constant flow of gas from the first stage body. This does make listening for leaks a bit challenging. When using one of these regs, it is important that both you and your buddy are aware of this.

 

[Phil_C]

I read a section from the SDI solo diving manual the other day which reckoned that a free flow/leak on the high pressure side of the first stage will take about 22 minutes to empty a full tank, whereas a free flow or leak on a regulator/low pressure side will take only 90 to 100 seconds. However if the O rings blows then it is a different matter. Maybe if it the bubbles were from a high pressure side leak this is why you still ended up with pretty much the same air left, despite seemingly leaking air for the whole dive. I know it sounds counter intuitive that a high pressure side leak takes longer to empty a tank, but I double checked it and this is what it was saying, due to the smaller apertures involved.

A dive leader here in north Cyprus was diving about ten days ago with a leaking o ring - constant small bubbles etc on descent, this then blew at about 20 metres, (it was a yoke fitting not DIN) she had to isolate the valve, air share and ascend. I wasn't on that dive, but my normal buddy was, we talked about it afterwards and I then discussed it with the instructor, she told me she knew she had a slight leak and dived it anyway because o ring failures are rare !

I wouldn't feel comfortable with it at all if I had bubbles leaking, but it does seem to be common to say this is situation is rare and don't worry.

I think maybe in the example here the instructor was showing the OP the opctopus for their benefit as much as for their wifes, probably thinking the bubble leak would not get any worse and wasn't a problem, but wanted to reassure the OP there was nothing to worry about and that is why they didn't want you to panic the OP's wife.