Checking your own tank valves

[udtfire]

i tell my students air is like being pregnant you either are or are not and air is all the way on or all the way off we do this in public safety diving so we can touch the valve and know it is on or off without looking we do it by touch only . as with any tec tool or gear first is it safe two does it make sense and three in a worst case event will it work
if it doesn't pass that test then rework your choices
dive safe and always think ahead

 

[thanksforallthefish]

It's a good idea to periodically check your valves every 5-10 minutes during the dive. Sweep through them all and make sure they're all properly on or off. The more cylinders and more valves you have, the more important the task.

WHY

 

[AfterDark]

I've torn my right rotator cuff twice, I don't have that kind of flexibility anymore. Before we go out I just tell everyone to keep their hands off my gear or there will be trouble. If they don't agree I don't go diving with them or if they don't like it they refuse to take me diving. Either way I'm safe. I also turn back a 1/4 turn on everything. Why? That's what I was taught.

 

[scubafanatic]

As one who's had to deal with a stuck-open valve more than once, I make sure mine's about a quarter turn off the stop. And it isn't just old valves... last one was summer before last on a reasonably new Scubapro valve. It's a pain to have to sit there holding the purge valve until the tank's empty before you can switch tanks for the next dive.
Rick

.....given the number of times we see/hear/read threads on this whole quarter-turn-issue causing scares/accidents/injuries/drownings (frequently enough to be approaching the beating-a-dead-horse threshold)...versus the number of times we see/hear/read threads on tank valves sticking open (essentially never).....and given the consequences of each (death versus purging a tank down to empty to change out regs...big deal!) .....I'm gonna stick with leaving tank valves full-on...BTW, which means just open the valve fully until it stops...no need to crank the valve open with maximum force as hard as possible, no need to 'weld' the valve open!)

......I've dove numerous times (like Bonaire...Cozumel) where rental tanks are rode hard and put away wet....annuals on such tanks are non-existant...and I've never seen/heard/experienced any cases of such tank valves sticking open...and these are some seriously worn/abused/thrashed valves/tanks.

 

[scubafanatic]

I hope this doesn't seem like a dumb question, but it's something I've wondered for a while, and this seems like a good thread to ask it.

Is there any guidance about how long your valve should or should not be open before you descend? I was told by a DM once that I shouldn't turn my air on until right before I jump in the water.

I'm most comfortable being solely responsible for my own gear in every way, including my tank valve - but I have to admit I'm not as flexible as I once was, and while I can reach it once the gear's on my back, it ain't easy (and I'll have sore shoulder muscles for a while if I do it) - although I could do it in a pinch if I had to. So I generally turn my own air on right before I gear up. However, one time on a boat a DM told me I should wait until the last moment to turn on my air. This means that I would have to do it after I geared up - something not so easy for me anymore - or ask someone else to do it (buddy or DM). I'm just uncomfortable with this. *I* want to turn on my valve myself...*I* want to control where it sits (I open it fully, but lightly - no hard cranking)...*I* want to be the one solely responsible if I ever do stupidly descend with my air off.

So...why shouldn't I turn on my valve right before I gear up, even if it's going to be several minutes before I can jump in, while I wait for the other divers ahead of me at the gate? Is there some technical, mechanical reason, some potential failure point caused by turning on my air well in advance?

...the only reason I can think of as to why the DM suggested this is that it's not uncommon for tanks to slip/fall out of tank racks....if that happens with the reg pressurized it's gonna cause one heck of a noise when your reg hits the ground/boat deck and breaks/snaps/pops off your 1st-stage! (yes, it's happened to me personally and to other divers I've seen !)

....however, I'm going to disagree with the DM on 'details'...while I don't leave my reg pressurized unattended on the boat tank rack, just before I'm ready to slip the tank harness on, I'll pressurize my regs...then 'gear up'....I see no reason to turn the tank valve on AFTER I've geared up.

Among other things....I like to check the tank pressure before I gear up to see if I've gotten a short fill...so I can have the boat top it off immediately if needed...also, the tank valve O-rings tend to fail, if they are going to fail, immediately at the moment of pressurizing the reg......if you are already sitting down, fully geared up, turn on the tanl valve, and then have the O-ring extrude/blow...that's gonna happen an inch away from your ears.....which will be LOUD ! ......scare the cr*p out of you, and be hard, especially in a state of panic/surprise, to have the wits to reach back and find the valve and turn it off !

 

[scubafanatic]

In my experience, rental tanks o-ring in high volume warm water destinations tend to leak more times than not. I recently spent two weeks diving with two friends, averaging 3-4 dives a day. On any given dive, 1, sometimes 2 of us had o-ring leaks. A few of the tanks leaked so bad that I asked for another and a couple of times I changed the o-ring myself from my save a dive kit. Leaks occurred randomly between 4 different divers, so I'm certain it's not the regs.

...let's just say that I think the government of Bonaire should sponsor me to come down at their expense (free dive trip) to swap out all their tank O-rings...because whenever I've been down there I've literally swapped out tank O-rings on DOZENS of tanks...for free, of course (both my tanks and buddies tanks).....honestly, I think they just wait for the tourist divers to update all their old O-rings.....most 'native' O-rings leaked to various extents, looked terrible/old/worn...and almost welded into the tank valve bodies they'd been in there so long! .....I wouldn't go there without at least a 100 spare O-rings in my save-a-dive-kit!

....BTW, I also tend to need to update tank O-rings on liveaboards, but it's not a big deal as I'm diving the same tank all week, so it only costs me one O-ring.

 

[b1gcountry]

I hope this doesn't seem like a dumb question, but it's something I've wondered for a while, and this seems like a good thread to ask it.

Is there any guidance about how long your valve should or should not be open before you descend? I was told by a DM once that I shouldn't turn my air on until right before I jump in the water.

I'm most comfortable being solely responsible for my own gear in every way, including my tank valve - but I have to admit I'm not as flexible as I once was, and while I can reach it once the gear's on my back, it ain't easy (and I'll have sore shoulder muscles for a while if I do it) - although I could do it in a pinch if I had to. So I generally turn my own air on right before I gear up. However, one time on a boat a DM told me I should wait until the last moment to turn on my air. This means that I would have to do it after I geared up - something not so easy for me anymore - or ask someone else to do it (buddy or DM). I'm just uncomfortable with this. *I* want to turn on my valve myself...*I* want to control where it sits (I open it fully, but lightly - no hard cranking)...*I* want to be the one solely responsible if I ever do stupidly descend with my air off.

So...why shouldn't I turn on my valve right before I gear up, even if it's going to be several minutes before I can jump in, while I wait for the other divers ahead of me at the gate? Is there some technical, mechanical reason, some potential failure point caused by turning on my air well in advance?

I'm not this person, so I can't speak for what they were actually thinking, but some folks like to have the same procedure every dive for ensuring important things like your air supply. If you turn the tank valve on at the same point every time you gear up, its easier to remember to do it, and easier to remember if you did it.

A problem I've seen a number of times is turning on your air when you set up your tanks, and then closing the valve. The system is still primed, and your SPG will still read tank pressure, so its harder to tell if your tank is shut off. Following your DM's advice above is one way of avoiding this situation.

I avoid it a different way by making sure to purge my system every time I close my valves. My rig is either on fully on or fully off and purged. I also make sure to pre-breathe my regs while watching my SPG for a jumping needle as the last thing before I step off the boat before every dive.

Tom

PS, I also back off the valve slightly whenever I turn it on. Otherwise, it wears out the little teflon washer around your valve stem, and the valve starts to stick open more.

 

[scubafanatic]

I do understand that, but most boats have a guy whose job it is to check valve. And on some boat, the operator will probably not let you dive if you refuse to let his highly qualified person verify that you valve is open before you jump.

It is so easy to check that it is OK that it's just not worth it for me to make an issue over touching my gear. I always turn my valve on just before I don my BCD and take a couple test breaths as I watch the SPG just before I jump.

yeah, some liveaboards do that as SOP...while you're standing at the jump gate, ready to splash, they check your tank valve anyway, no matter what...and I completely understand their position...if I were in their shoes, I'd do the same thing......they are responsible and each diver is an unknown quantity...they have no idea if any given diver is a newbie....a pro...an idiot....or just made a simple human error and 'forgot' just this one time......but as I always do the breathe on the reg while watching the SPG 'test' just before splashdown, as the ultimate safety check anyway...I'm Ok with their policies.

 

[Cave Diver]

A problem I've seen a number of times is turning on your air when you set up your tanks, and then closing the valve. The system is still primed, and your SPG will still read tank pressure, so its harder to tell if your tank is shut off. Following your DM's advice above is one way of avoiding this situation.

2-3 breaths from each reg just before entering the water. This assures me both regs are working and my air is on.

 

[DelrayDM]

always take a few breaths from my second stages prior to entering the water while watching my pressure gauge. If the needle leaps up and down, your valve isn't open all the way. Quick and easy to chec

Probably my 15th dive in my life, as I got in position on the platform to step off, some crewmember shut off my air. Sure glad I was watching the SPG WHILE he was fiddling with my tank.

"Excuse me, now that you have turned my air off, would you please turn it back on?"

hmmm... "righty-tighty / lefty loosey" maybe we should teach "righty-rigormortis / lefty lives" ???

I turn the air on BEFORE I put my gear on.

Don't want to take the (very small) chance that I fall off the boat, wearing my gear, with the air still off.

If the o-ring is "going to blow", I want it to happen before I have my head up close to the valve.

When I stand up to get in position to leave the boat, I am breathing from the reg. I am very happy to "waste" gas on the surface as a test that everything is on and working. (Before that I have test breathed through all three second-stage regulators, I have tested my 'air-horn', and BCD fill / deflate valves.)

If the crew / DM hears you breathing through your reg as you position yourself on the platform, he should deduce that your air is on, hopefully suppressing the urge to turn it off for me.