Keeping Isolator Valve Closed

[Walter Pickel]

where did the reg explode at EN, I was there in March and saw a bunch of parts at about 150 ft deep downstream.

It was at about 80' feet on the tail end of the dive -- almost to the chimney.

[Moonfuzzy]

where did the reg explode at EN, I was there in March and saw a bunch of parts at about 150 ft deep downstream.

It was at about 80' feet on the tail end of the dive -- almost to the chimney.

Did the diver get a concussion or something? I have wondered what would happen if something on my tank exploded behind my head...

[DeepBound]

Did the diver get a concussion or something? I have wondered what would happen if something on my tank exploded behind my head...

Here's another account of a reg exploding and hurting someone's head...
http://cavediver.net/phpbb2/viewtopic.php?t=5243

[teqdiver]

Maybe I'll try leaving it open just a crack, like you said the Australians did, until I can get into sidemount.

Not a good idea either. Sometimes the HP seats in the valves will get a deep groove in it. It can be almost a couple of full turns of the knob to actually open the valve. So, when you start out with the knob just cracked with a deep-grooved seat it is actually closed. Then that can lead to LOG/OOG situations needlessly. I have seen this happen at least twice. FYI....

Ryan Parkevich

[Shadowjack]

where did the reg explode at EN, I was there in March and saw a bunch of parts at about 150 ft deep downstream.

It was at about 80' feet on the tail end of the dive -- almost to the chimney.

( He's talking about me ) here's what happened , It was a mid week dive, the plan was just stay around the cone. 4 of us were there, Walter and I, one person checking out a RB and the other new to the nest. I was playing around with my video camera. About 30 minutes in to the dive I have a explosion in front of me all I see are bubbles, knowing that it was a second stage but not which one, I shut the isolater down while I figured out which one ( the BS about how long it takes to shut down a fully open valve – 20 seconds 30 seconds BS!, my left hand shut that valve down faster than a impact wrench! I’ve always wonders about reaching my valves- not a issue in a real case, I wrapped my hand about the handle! ) in the 3 seconds it took me to close the isolator I figured out it was the backup 2nd stage that had issues, so I shut down that post in about another 3 seconds ( never knew I could turn a valve that fast! ) I also dropped my video camera as I was doing the valves, took note of where the other 3 divers were around me and swam slowly (yes, slowly) to the closest diver who was ready with their long hose for me if I needed it. The whole thing took about 30 seconds. I got comfortable at that point, told Walter to get my camera ( THANKS again Walter ) . Then I started to think again, all the way to that point it was training and instinct. I realized how I did everything to that point, I didn’t think I just did it. No panic no nothing. The rest of the dive was normal. BTW – the video camera was on the whole time, great video!
Yes, there was a little voice in the back of my head after that dive, but I shut him up by going back there and doing a 50min BT downstream later that week.


Eric

[FW]

... About 30 minutes in to the dive I have a explosion in front of me all I see are bubbles...

Eric

What actually happened to the reg?

[aw]

For a short low section when carrying a stage, it is very doable to pull the stage by the neck out and to the side (into the sidemount position) to pass through the low area. It ties up one hand, so long stretches is not advisable.

[skip]

I dove with some Australians in Mexico. They were used to diving independents. They started the trip with the isolator fully closed. Then they went to a just barely cracked open isolator. By the end of the trip, they just left it open.

If you are really concerned about loosing all your gas, you should go sidemount, not back mounted independants. At least you can reach the valves. You can also "valve" air out of one with a freeflowing reg, which you can't do backmount.

"At least you can reach the valves?!!" When has it become acceptable that cave divers can not reach the valves?

I haven't read on down the thread, but I must say that if you can reach the knobs then you can ""valve air out of one with a freeflowing reg." I do valve drills at every stop and would have no problem turning any one of the three on and off at will, at any time. And I have dove independents and manifolded. no difference in reaching the valves.

I can not believe any cave diver would have a problem with this and if they do, they need to get that fixed quick, in a pool, not in a cave!

I'm not against sidemount, I am doing a bit myself, but reaching valves is not a reason to dive sidemount versus backmount. I won't even accept ease of reaching as a reason; if it's easier one way or the other, then you need to spend a bit more time in the gym.

-skip

-skip

[Gary]

go sidemount, not back mounted independants. At least you can reach the valves. You can also "valve" air out of one with a freeflowing reg, which you can't do backmount.

"At least you can reach the valves?!!" When has it become acceptable that cave divers can not reach the valves?

Although I prefer the convenience and ease using independent backmount instead of sidemount I'm sure Forest was saying that in sidemount you can reach the valves so that you can easily access/swap out the regulators or breathe right off the valve - something that is much more difficult to do with backmounted tanks.

[DeepBound]

go sidemount, not back mounted independants. At least you can reach the valves. You can also "valve" air out of one with a freeflowing reg, which you can't do backmount.

"At least you can reach the valves?!!" When has it become acceptable that cave divers can not reach the valves?

Although I prefer the convenience and ease using independent backmount instead of sidemount I'm sure Forest was saying that in sidemount you can reach the valves so that you can easily access/swap out the regulators or breathe right off the valve - something that is much more difficult to do with backmounted tanks.

Have any of you practiced swapping regs between your sidemount tanks underwater? Hopefully somewhere safe like a pool? I mean without a third regulator/stage of course. It sounds like it would be pretty scary to have to do that in a cave!