# Scuba valve, the 1/4 turn that kills



## coolbluestreak

Alyssa sent me this article and it got me thinking...this is what I/we do... 

The Quarter Turn That Kills Leave a reply At least one diver won’t be spending the holidays with family and friends this year, thanks to the dangerous practice of opening a scuba tank valve all the way, only to close it back a quarter turn. According to an article in the Daytona Beach News-Journal, an Edgewater, Florida, diver perished October 9 with more than 140 bar/2,000 psi remaining in his tank. His valve, however, was only open one-quarter turn. The same thing happened to cave-diving pioneer Sheck Exley over four decades ago. Exley was descending, head-first, into a narrow crack in what is now Wes Skiles Peacock Springs State Park. Exley had accidentally closed his tank valve all the way, then opened it a partial turn, as he was taught. His regulator still breathed fine at the surface but, upside down at 20 m/65 ft, Exley found himself starved for air. Exley ended up surviving what had been a very close call, and made it a standard of practice in cave diver training to either open valves all the way or fully close them. This has become a standard of practice in tech diver training as well. For reasons passing understanding, however, it has not become a standard of practice in recreational diving. Where Does This Come From? It’s common in industries ranging from welding to HVAC to never fully open a cylinder valve. The concern is that, if you try to force open a valve that is already open, you may damage the valve. Well, guess what? If your acetylene valve is only partially open, you may not be able to weld. If your scuba tank is only partially open, you may very well die. In shallow water, a partially open valve may still be capable of delivering sufficient gas. At depth, however, the same valve setting can leave a diver starved for air. Forcing a tank valve past its normal stopping point in either direction is a bad idea — even though modern scuba valves are a lot harder to damage than people realize. Curiously, you never hear dive instructors say, “Close your valve all the way and then open it a partial turn.” In the final analysis, valve damage beats being dead. So What Should You be Doing? So that you live to enjoy another holiday: Open and close scuba tank valves only by turning them very gently. Stop as soon as you feel resistance. A valve turnwheel that does not turn easily requires survice. Make sure your valves are either all the way open, or all the way closed. Be wary of well-meaning buddies and even dive boat crew checking your valve position for you. Even divemasters have been known to accidentally close a valve all the way, then open it a partial turn. Because this can work in shallow water, divers may not realize they are at risk until it is too late. To help ensure your valve is open all the way, take several deep breaths from your regulator while looking at your pressure gauge. The needle or reading should hold rock steady. If it drops with each breath, your valve is closed. If it fluctuates with each breath, your valve is only partially open. Do not dive until the valve is open all the way. The next time you run into an instructor teaching this archaic and dangerous practice, set him straight. Better to ruffle some feathers than to bury a dead student. This entry was posted in Diver Training on December 24, 2013.


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## Waste-N-Away

not sure anyone ever explained to me why but I was always taught to open the valve all the way and then turn back 1/4 turn. doesnt matter i havent dove in years and wont again after my uncle almost died getting bent. dont get me wrong loved to dive just not for me anymore......


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## 36Hatt

I believe the reason for the quarter turn was so that anyone could check the position of the valve before a dive by opening it that quarter turn to the stop to be sure it was open. Easy to do. If you leave it all the way open, and someone checks, they wouldn't know for sure if it was all the way open, or closed tightly.

I will continue this practice. Your dive buddy should be checking your tank as well.

Blaine


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## Worn Out

*I took my lessons in'66...*

and they told me that was so if you "ran out of air" you could open it it up and have a couple hundred lbs. left... I guess you weren't supposed to panic, just reach over your shoulder and get some air...It made sense at the time, but the valves may have c
hanged...Any comment Jim?


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## MillerTime

Interesting article for sure but it doesn't seem very well written. They keep flipping back and forth between having it a quarter turn open and a quarter turn closed. From the article I don't think there is any way someone would still have 2000 psi with their valve only a quarter of a turn closed. Seems to me like they had an argument for a story and used different "facts" to support it.


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## Telum Pisces

Ok, I can tell you that this can happen. It happened to me. Here is what happened.

We were doing a somewhat deep rec dive to about 140'. I start to head down the anchor rope and everything is going great. I get to about 120 feet and my air goes from breathing fine to all of a sudden sipping air through a coffee straw that is pinched. 

I immediately start to ascend and begin to run through some possibilities in my head as to what is wrong. I switch to my backup reg only to have the same thing going on. At this point, I was not getting enough air and I felt myself begin to get light headed and I begin to panic for a moment. But something kicks in telling me to calm down. I close my eyes and calm myself down. I am getting just enough air to stay alive at a calm level. Anything else, I know I will not make it. I look at my computer and air and realize that I have enough, it's just not getting to me at normal breathing rates. I continue to calm myself down all while going up at a safe pace yet faster. I figured better a ride in the chamber and alive vs dead. 

I finally make it to about 35' and my air comes back full blast and I am relieved. I have enough sense to to a very lengthy safety stop and ease my way back onto the boat. 

After figuring out that I just about died, I check my valve and it was barely on. Yep, I had turned my air off only to turn it back on only a quarter of a turn before splashing. 

It's happened to me and can happen to you. I triple check and have my buddy triple check my air from now on.


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## Billybob+

It's not the 1/4 closed or open or air off that kills, it's the panic that ensues. If you remain calm you will have enough air to begin a slow ascent, If you panic and begin to hyperventilate you'll over demand the regulator (with the valve almost closed that is) and will "feel" like you aren't getting any air which will escalate the panic and the hyperventilation.

the easiest way to avoid this is simply the last check before leaving the boat, take your pressure gauge, while watching it closely, draw 2-3 DEEP, hard breathes. If the needle remains rock solid you're good to go, if it dips a bit (even 100-200 pounds) and restores as soon as the breath is complete, the air supply isn't meeting the demand of the regulator 1st stage, hence, your air isn't on all the way.


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## TONER

Been there done that only 1/4 turn open sucks literaly doesn't get hard to breathe until around 40' or so but as long as you don't panic your fine.
unless your ambidextrous you have to just take your BC off and turn it on.
your guage will show actual psi in tank but will drop a few hundred psi every breath and go back up between breathes.
its a good topic to cover probably should be covered while getting certified so its not so Much of a surprise when it happens sounds like it could save lives.


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## coolbluestreak

I would love to have some of the new tank valves with the visual red/green indications but I'm not going to replace a perfectly good valve for that reason alone.

I think it's just a good reminder to be consistent in the way we set up our gear and if we second guess, we should stop and make sure that our gear is right/safe.


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## TONER

Jeremy you know how it is on my boat it's always a race for the first one in and to the bottom:yes: ! Heck one day I forgot to put my fins on that sucked :blink:!


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## MillerTime

TONER said:


> Jeremy you know how it is on my boat it's always a race for the first one in and to the bottom:yes: ! Heck one day I forgot to put my fins on that sucked :blink:!


You have to get in fast before Chad shoots all the fish. I think you also forgot your computer one day too!


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## SaltAddict

I always check to be sure I can reach back and "handle" that valve before I splash. You should be able to close or open that valve without removing gear. It is good practice on a safety stop to reach that valve and turn it. Enough practice makes it second nature. 

I was always taught to open wide and come back a 1/4 turn. The back side of the valve isn't designed as a "seat." (This is what I was told. 
I was never taught to close and then back out a 1/4 turn. The front side IS designed as a "seat." Meaning it is designed to sit tight.


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## coolbluestreak

MillerTime said:


> You have to get in fast before Chad shoots all the fish.


 If he gets down first he shoots the biggest fish, if you get down there first and shoot a big fish, he'll shoot a bigger one. I don't get it?


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## sealark

I have been diving since I was 10 years old 60 years and have never heard of anyone tightening there valve down instead of opening it and then backing open 1/4 turn. If someone does that they don't understand the basic righty tighty lefty loosey. and shouldn't have been certified. The main reason to open all the way and then close it 1/4 turn is because some of the older valves could get frozen in the fully open position and if you have a regulator free flow you can slow down the flow to make an emergency assent. Double hose regulators were notorious for free flowing. Plus in those days there were no pressure gauges only a 500 lb pull down reserve. Things have changed with technology. Many times I have had to crank down on a tank valve to slow down a double hose free flow. I also remember carrying around a 2 lb box of Corn Starch to get into a ALL neoprene wet suit before nylon lining came out. Those were the good old days.


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## dsar592

This is some good information. Thanks for posting it.


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## Firefishvideo

SaltAddict said:


> I always check to be sure I can reach back and "handle" that valve before I splash. You should be able to close or open that valve without removing gear. It is good practice on a safety stop to reach that valve and turn it. Enough practice makes it second nature.
> 
> I was always taught to open wide and come back a 1/4 turn. The back side of the valve isn't designed as a "seat." (This is what I was told.
> I was never taught to close and then back out a 1/4 turn. The front side IS designed as a "seat." Meaning it is designed to sit tight.


BINGO!
If you cant reach and operate your valve in the water.....you are NOT safe.
Do what you want -but for me......closing the valve slightly after opening means that if I reach back and check it - I can rotate the valve to check its position. If its jammed in either direction....I may not have the strength to rotate it with it behind my back....and may jam it further if I pick the wrong way to begin cranking on it.
Watch the needle on the pressure gauge....it will bounce if the valve is partially closed.


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## sealark

Yes if you can't reach the valve you shouldn't be diving. I'm 70 and went yesterday (wed) and reached around to see if I could still reach it in a 7mm farmer john with hooded vest. No problem. Guess I'm still good to go for a few more years.


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