OOA at 90 FFW...well kinda!!!

[DeepB]

actually when i started diving i was also told to turn it 1/4 back. but now it is always all the way turned, also for another reason. When you have to turn it off under water (me diving in cold water), then it only goes into one direction. actually i also do not know why some turn it 1/4 back.

glad it worked out for you.

greetings
Daniel

 

[captndale]

It has always been common practice with water and steam valves to open them and turn them back 1/4 turn so that when they start to corrode they are less ligely to freeze in place. This has never been a problem with scuba valves, nevertheless, early instructors taught this procedure and the practice continues to this day. I believe that turning valves back 1/4 turn is a dangerous practice. It is a practice that has no value whatsoever. It is a practice that has resulted in many emergencies and some accidents.

 

[Divin'Papaw]

It has always been common practice with water and steam valves to open them and turn them back 1/4 turn so that when they start to corrode they are less ligely to freeze in place. This has never been a problem with scuba valves, nevertheless, early instructors taught this procedure and the practice continues to this day. I believe that turning valves back 1/4 turn is a dangerous practice. It is a practice that has no value whatsoever. It is a practice that has resulted in many emergencies and some accidents.

I completely agree with Dale. When I turn mine on, I turn it all the way on. I see no reason to do otherwise. If it's off, you know it. If it's on, you know it's on all the way.

I'm also puzzled that so many people turn their air off when it's already on. You're turning it in the OPPOSITE direction, right? And you don't notice that?

Left is loose or open, right is tight or closed. How many times do people turn their tanks on and off but yet end up confused about which way is on vs. off? What about wrist muscle memory? I just don't get it. While facing the valve, all the way to the right or clockwise is CLOSED, all the way to the left or counterclockwise is OPEN. The muscle memory in my wrist just "knows" what to do after doing it so many times. I just don't get why this messes up so many people.

 

[JEScholz]

Sounds like you handled it well. no panic, stop and think, handle one problem at a time... I don't know if this practice would have made a difference but I always take a couple of breaths and put a shot into the BC before I do the giant stride.

I wonder why scuba manufacturers don't incorporate a ratcheting handle into tanks similar to what is mandated on fire fighting air tanks. You can't turn them off unless you push in and turn at the same time. This would also prevent the "roll off" problem I hear from cave divers on doubles.

 

[wreckchick]

I'm probably overstepping on the roll-off issue, but there is also the problem of having a freeflow and needing to shut down the offending valve. Time is air in this situation so it makes sense to be able to manipulate the valve easily.

If I take my eyes off my tank on a boat, I check the valve before I get in. I also ask everyone to leave it alone. I tell the DM to please not check my air before I go in. The last thing I do is take a couple deep breaths off my primary while looking at my SPG. I can also reach my valve to turn it on (or off) while I'm in the water.

I make it a point to do this demo on the deck of the boat with students so they know what to look for with a valve that's cracked open and one that's all the way off. It's a pretty nice demo for them. I ask them to check to see if their air is on. They check the gauge, it's reading full, they nod. I reach back turn their air OFF and ask again. Now the tank still looks full and they're confused. I ask them to take a couple breaths while continuing to look at the SPG and they watch the needle drop. I then crack the valve and go through the same routine. Now I turn the tank all the way back on, all the while they're looking at their gauges. They know exactly what it all looks like and how to check it on the deck of the boat hopefully preventing any issues in the future.

Rachel

 

[Web Monkey]

I'm not sure what to do about people turning off my air other than to just not allow anyone else to touch it.

The very last thing I do before taking a step off the boat is to dump a bunch of air into my BC while taking several big breaths and watching my computer. If the pressure drops, something is wrong.

Also I wait to feel my BC actually inflating and don't just listen for the noise. A number of times, I've see divers hit their inflator, do a giant-stride and hit the water with an empty BC because the pull dump was stuck open.

Terry

 

[Web Monkey]

Can anyone shed some light on the 1/4 back thing?
Thanks

Some valves stick open. The 1/4 turn thing keeps this from happening. However, sticking is really an indication that the valve needs service, not special handling.

Terry

 

[ClayJar]

Some valves stick open. The 1/4 turn thing keeps this from happening. However, sticking is really an indication that the valve needs service, not special handling.

They wouldn't need a quarter turn, anyway, eh? You only need to back it just off the limit. Turning it maybe 5-10°, not 90°, should be plenty to keep it from sticking. (At least, that seems to work for all the sticking valves I've met on rental tanks.)

 

[MikeFerrara]

I guess it's good that so many people breath off the reg at the surface while watching the guage but it doesn't tell you everything. Since a "breath" is much less air at the surface than it is at depth, everything may function just fine at the surface but NOT at depth.

The best way to check the position of a valve is to reach back and check it. I don't worry much about someone messing with my valves because I'm going to reach back and check it anyway...be able to reach your valves. Check before you jump in, check again before you descend, check whenever you feel like it's a good idea to be checking or just to practice.

 

[wreckchick]

Mike, I've found that a cracked valve on the surface will show a needle fluctuation on the SPG so it is possible to see it before I splash.

R