binobanana
Contributor
thats why you don't forget to turn your air on! Thats the way you know how far open your valve is! I turn it back so far that i can turn it in both ways it does not matter how far 1/8, 1/4,
Half a turn back
- Thread starter sphenisc
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
Bino, your answer makes no sense. If you turn it so far back that you can turn it easily in both ways, it makes it harder to know if it was on or off.
Lets face it: simplest thing to do is to know which way is on, and turn your tank all the way on. If you can't remember which way is on and which way is off, it is my opinion that you should rethink your underwater safety.
Given that your air tank is your life support, doesn't it make sense to be familiar with its operation? Infact, I think it is vitally important that divers be able to reach around and manipulate their valve underwater. You never know when something will happen to move your valve. And then, when you reach around, it is important to know which way is on and off, because turning your air off yourself underwater would not be the brightest thing to do. (yes, I know us technical divers do valve drills, but I'm speaking to single tank recreational divers here. May God help the technical diver who doesn't know if his tank is on or off...) I do not see any excuse for not knowing which way is on or off, or for not checking your air yourself before you don your equipment, or for letting anyone mess with your gear unless you specifically request it. Air is important, a diver needs to manage it themselves without help. When you need help to run your life support equipment on a dive, you run the risk of dying if your help is not there to help you when you have a problem or complication of the dive.
Lets face it: simplest thing to do is to know which way is on, and turn your tank all the way on. If you can't remember which way is on and which way is off, it is my opinion that you should rethink your underwater safety.
Given that your air tank is your life support, doesn't it make sense to be familiar with its operation? Infact, I think it is vitally important that divers be able to reach around and manipulate their valve underwater. You never know when something will happen to move your valve. And then, when you reach around, it is important to know which way is on and off, because turning your air off yourself underwater would not be the brightest thing to do. (yes, I know us technical divers do valve drills, but I'm speaking to single tank recreational divers here. May God help the technical diver who doesn't know if his tank is on or off...) I do not see any excuse for not knowing which way is on or off, or for not checking your air yourself before you don your equipment, or for letting anyone mess with your gear unless you specifically request it. Air is important, a diver needs to manage it themselves without help. When you need help to run your life support equipment on a dive, you run the risk of dying if your help is not there to help you when you have a problem or complication of the dive.
- Messages
- 1,938
- Reaction score
- 168
- # of dives
- 500 - 999
I agree there's no real excuse for not knowing if your air is on or not -- but it's the rare diver who hasn't at least once in their diving life forgot.
The 1/4 turn rule, to me, makes sense for rec divers who are going to be diving with a DM -- who wants to easily check to see if the air is on. By only having to twist the knob a bit, hit resistance and go "ok, it's on," the DM can check everyone very quickly -- often without them even noticing he's doing it.
Other than that, I don't know enough about valve operations to comment. I've heard so many conflicting statements around if it is needed or not to preserve valve life. I have no clue what the real story is there.
The 1/4 turn rule, to me, makes sense for rec divers who are going to be diving with a DM -- who wants to easily check to see if the air is on. By only having to twist the knob a bit, hit resistance and go "ok, it's on," the DM can check everyone very quickly -- often without them even noticing he's doing it.
Other than that, I don't know enough about valve operations to comment. I've heard so many conflicting statements around if it is needed or not to preserve valve life. I have no clue what the real story is there.
Atomic_Diver
Scubaboard Enthusiast
also i heard so it doesn't get stuck open.....
Texasdivechick
Contributor
- Messages
- 273
- Reaction score
- 3
- # of dives
- 100 - 199
I can speak from experience that I stopped the practice of quarter turn back of my valve when I suddenly couldn't get air at 60fsw five minutes into the dive. Turns out my buddy (we both had less than 10 dives at the time) had "checked my air" not thinking that I had already turned it on and he closed the valve instead, only with the quarter turn. That was enough pressure for me to test my regulator on the surface and breathe until we hit 60 ft, then surprise!!! - nothing came out.
I learned that day what a "cracked tank" meant. I also learned that day to NEVER let a buddy touch my valves again.
SolarStorm
Contributor
So would this not make more sense? If the valve will not turn at all leave it. Would not your first breath tell you it is closed? Ie you would only be 2 feet below the surface. This way the check then becomes one of see if it open ALL THE WAY instead of partially open. IE it is a paritally open valve that will give out at 60'
This doesnt alleviate the "wrenching it open" problem or the "freeze problem" if it exists in todays valves. Still want to talk to my mechanical engineer friend about the freeze up though.
I agree that you should never force a valve open or closed.
This doesnt alleviate the "wrenching it open" problem or the "freeze problem" if it exists in todays valves. Still want to talk to my mechanical engineer friend about the freeze up though.
I agree that you should never force a valve open or closed.
Apparently, I only got one good picture of the product, and none of the booth. I think I got distracted by the arrival of a friend before I finished. I might have more pictures on another card, but this is enough to show the product atleast.
I did take the time to position them, so you can see it fully closed, fully open, and halfway.
I did take the time to position them, so you can see it fully closed, fully open, and halfway.
SolarStorm
Contributor
Ok, talked with my Mech Eng buddy. He can think of no reason why openning the valve all the way would make it more prone to freeze up. (provided it is designed correctly, he added)
He did say it may be easier to break loose a frozen valve that is a quarter turn back due being able to apply pressure in both directions. Not an engineering answer, just that one may be able to turn with more strength in one direction or another. Although he said better wait for the valve to unthaw than force it when frozen.
His other sage advice was not to over tighten in either the closed or open position. If designed correctly, the valve should stop clean in both the open or closed position. If it requires "tightening" he said it was probably time to replace/repair the valve.
He then stated, "but what do I know? I have never worked on dive equipment".
Everything he said made sense, so I my plan is open the valves completely and not let anyone touch them save during the buddy check.
I am new at this, but, if the valve only turns one way, it must be either completely open or closed. If it is closed, you would not be able to draw a breath, unless there was some air already in your lines, but that would still only be a couple of breaths max. So you should only be a couple of feet down by the time you go "DUH!".
You experienced divers please correct any of this for me. To much of this sounds surrounded in myth and tradition.
JahJahWarrior, the color coded valves look to be a great idea.
He did say it may be easier to break loose a frozen valve that is a quarter turn back due being able to apply pressure in both directions. Not an engineering answer, just that one may be able to turn with more strength in one direction or another. Although he said better wait for the valve to unthaw than force it when frozen.
His other sage advice was not to over tighten in either the closed or open position. If designed correctly, the valve should stop clean in both the open or closed position. If it requires "tightening" he said it was probably time to replace/repair the valve.
He then stated, "but what do I know? I have never worked on dive equipment".
Everything he said made sense, so I my plan is open the valves completely and not let anyone touch them save during the buddy check.
I am new at this, but, if the valve only turns one way, it must be either completely open or closed. If it is closed, you would not be able to draw a breath, unless there was some air already in your lines, but that would still only be a couple of breaths max. So you should only be a couple of feet down by the time you go "DUH!".
You experienced divers please correct any of this for me. To much of this sounds surrounded in myth and tradition.
JahJahWarrior, the color coded valves look to be a great idea.
LeadTurn_SD
Contributor
You've got it!The very small risk of a modern valve sticking OPEN (usually due to to operator error: Too much force used) is a small risk compared to jumping in the water with a valve only partially open and going OOA at depth.
And if a tank valve is going to "stick", I'd rather have it stuck open (so the tank can be drained and the valve removed safely) than closed (because it becomes a big problem to remove a badly stuck-closed valve from a tank with air in it :shocked2: ).
Best wishes.
liuk3
Contributor
I feel like the best insurance is to practice being able to reach your valve on your own to manipulate and open/close if you need to do so. I do this in the water on the surface to stretch my drysuit out and make sure that my valve is open before I descend.
Similar threads
