Second stage exhaust check valve failed open, flooding the reg when breathing

[uwxplorer]

That latter option sounds tricky to implement at 30 ft, holding a SMB and drifting in blue water, alone...

 

[PfcAJ]

You could move your long hose 2nd stage over to your deco gas. That's a pretty easy operation under water.

But it for a short deco, I'd probably just share the o2 with my buddy and not worry about opening regs and swapping stuff out.

 

[redacted]

If I took the exhaust cover off I could .


OK, decided to do it.

First picture is how the valve looks.
View attachment 196218

And this is the cover, which requires a narrow straight edge of some kind to get off, so maybe with a blunt-tipped knife, but I'd do it from the face cover. You have to press against that tab, which is inside a ribbed exhaust housing without much room. A pinky will not fit from the back.

View attachment 196219

Thanks. That is a pretty large and exposed exhaust valve. I wonder if a horizontal ridge on the cover, like the vertical ridge that is already there, might make it more resistant to such problems.

 

[John C. Ratliff]

I considered mentioning, but I decided the OP probably didn't need to hear it. If you plan your gas well enough to get out on back gas should your deco bottle fail, you know that attempting to swap a reg underwater is a real possibility should violating deco be your only alternative. Conversely, if you can safely wait it out and have the back gas to do it, why flood two regs just to shave some deco time?

In the case cited above of Chris and Chrissy Rouse, perhaps, to save two lives? Missing decompression in the manner that they did cost two divers their lives. I wanted to mention it as an option when other options have run out. The problem is that divers are stressed, and when out-of-air have nothing left in their lungs too. So this option must be kept in mind and used before a diver gets into this situation.

SeaRat

 

[Michael Guerrero]

I considered mentioning, but I decided the OP probably didn't need to hear it. If you plan your gas well enough to get out on back gas should your deco bottle fail, you know that attempting to swap a reg underwater is a real possibility should violating deco be your only alternative. Conversely, if you can safely wait it out and have the back gas to do it, why flood two regs just to shave some deco time?

All my 2nd stages are only hand tight for this very reason. Malfunctioning second stage on my deco bottle. No problem, turn the valve off, pull it off, swap it with another one, turn it back on and voila. No feathering (though I've done that before and it's not a huge deal), and no stress.

---------- Post added October 29th, 2014 at 02:04 PM ----------

Thanks. That is a pretty large and exposed exhaust valve. I wonder if a horizontal ridge on the cover, like the vertical ridge that is already there, might make it more resistant to such problems.

It has horizontal fins along the side. Like I said, you can't even get a pinky in there.

---------- Post added October 29th, 2014 at 02:10 PM ----------

In the case cited above of Chris and Chrissy Rouse, perhaps, to save two lives? Missing decompression in the manner that they did cost two divers their lives. I wanted to mention it as an option when other options have run out. The problem is that divers are stressed, and when out-of-air have nothing left in their lungs too. So this option must be kept in mind and used before a diver gets into this situation.

SeaRat

I think it's a valid consideration John and I would certainly swap 1st stages underwater if needed to get a working deco bottle, but this isn't what killed them IMO. What killed them, besides a cavalier attitude to 1) diving deep air below 220' when trimix was available, and 2) being wreckless inside a wreck, was Chrissy being pinned under a china cabinet for a long time while panicking and his father only barely getting him out. Then, they came out the wrong part of the Doria and couldn't find their stage tanks. They continued to search for a while too, way overstaying their BT.

In my view, these guys were dead before they left the wreck.

Point well taken that swapping regs underwater is a survival technique and something divers should be exposed to in training (probably at the technical level). But I don't think the example you use is as relevant as there were a lot of other, more serious problems with the dive than a ripped mouthpiece.

Mike

 

[Dr. Lecter]

All my 2nd stages are only hand tight for this very reason. Malfunctioning second stage on my deco bottle. No problem, turn the valve off, pull it off, swap it with another one, turn it back on and voila. No feathering (though I've done that before and it's not a huge deal), and no stress.

Um, no, not what's being suggested. While I'm glad that's worked for you so far, I'll stick with reg/hose connections that are correctly torqued. If I have to swap a reg, it's coming off the valve and getting completely swapped...which is a good reason not to go nuts with cranking the DIN threads into the valve.

But hand-tight threads on all regs just so you can swap 2nds underwater? No freaking way. Carry a tiny wrench on some bungie if you're that interested in swapping 2nds rather than whole regs.

 

[John C. Ratliff]

Um, no, not what's being suggested. While I'm glad that's worked for you so far, I'll stick with reg/hose connections that are correctly torqued. If I have to swap a reg, it's coming off the valve and getting completely swapped...which is a good reason not to go nuts with cranking the DIN threads into the valve.

But hand-tight threads on all regs just so you can swap 2nds underwater? No freaking way. Carry a tiny wrench on some bungie if you're that interested in swapping 2nds rather than whole regs.

Dr. Lecter,

That's a very interesting statement. You obviously are talking about DIN fittings, as the US yolk fitting (A-Clamp) has a hand screw on it. I have not heard of torquing a DIN fitting or a yolk fitting since we went away from the flat teflon washers on valves (early 1950s). To my way of thinking, from the engineering side, if a torque wrench was needed, the DIN fittings would not have a round knurled ring for hand-tightening the fitting against the sealing surface. The DIN fitting requiring a torque wrench would have a flat surface for the wrench to seat upon. I have never used a torque wrench to tighten my regulator first stage connection to a valve, and have never had any problems with it either. However, as you stated, wrenching the second stage regulator hose is a requirement.

I just wanted to clarify the statement that it is not the first stage connection to the valve we're talking about, but the hose fittings connecting the first and second stages of the regulator, and the other regulator hose fittings.

Michael,

I agree with you about the Rouse's, that there were many, many breaks in protocol. However I think it was the submarine U-Boat the U-WHO. I used it as it was the only example I had of a malfunctioning second stage where the person inhaled water. I actually had one mouthpiece split, but never got water through it.

SeaRat

 

[PfcAJ]

Don't do that hand tight bull****. Spanner tight and take a spanner with you in your pocket if you want to consider swapping 2nd stages underwater.

One of these days, you WILL have a hose come off from doing that.

 

[Max Speed]

Then, they came out the wrong part of the Doria and couldn't find their stage tanks.

Mike

Yeah, there's no way that was survivable since they left their tanks on the U-269!

 

[Michael Guerrero]

Um, no, not what's being suggested. While I'm glad that's worked for you so far, I'll stick with reg/hose connections that are correctly torqued. If I have to swap a reg, it's coming off the valve and getting completely swapped...which is a good reason not to go nuts with cranking the DIN threads into the valve.

But hand-tight threads on all regs just so you can swap 2nds underwater? No freaking way. Carry a tiny wrench on some bungie if you're that interested in swapping 2nds rather than whole regs.

I feel like you're really telling me to bring my torque wrench diving because it's good to have them "correctly" torqued, which just having a tiny wrench wouldn't accomplish due to being able to still under/over torque them without the torque wrench. But honestly, I've never seen anyone at a dive shop use a torque wrench to apply the "correct" torque. I've just seen some people crank on them a little, and some a lot.

And really, I think the principle is the same whether you're talking about 1st or 2nd stages. You can remove either one under water from one tank to another if necessary and if you think it's prudent. And I think this should be something discussed with divers because it doesn't always occur to people that it's an option. However, to say that this thread is only talking about first stages is kind of splitting hairs. Especially since the issue originally described was with a second stage.

But hey, maybe it's just me being nitpicky .

---------- Post added October 29th, 2014 at 08:05 PM ----------

Michael,

I agree with you about the Rouse's, that there were many, many breaks in protocol. However I think it was the submarine U-Boat the U-WHO. I used it as it was the only example I had of a malfunctioning second stage where the person inhaled water. I actually had one mouthpiece split, but never got water through it.

SeaRat

Oops, you're right. Got my wrecks mixed up.