Valves "full open" or not?

[Rainer]

I remember reading somewhere that fully open was correct. Almost everyone I dive with including instructors like to go full and then do the half turn back. Is this still the standard for PADI? I am going through the IDC in a few months, so I am sure it will be covered there.

Half a turn is WAY too much in my opinion. When I say I back them off, I mean maybe 1/8 turn, probably less. I want near instant feedback about a mistake, without jamming a valve if wrong.

 

[perdidochas]

Half a turn is WAY too much in my opinion. When I say I back them off, I mean maybe 1/8 turn, probably less. I want near instant feedback about a mistake, without jamming a valve if wrong.

I was taught to do that. Back it off just a bit.

 

[do it easy]

My valves are fully open or fully closed. I don't back them off when open, but I don't apply a lot of force when it hits the stop (the motion is turn until fully open, then back off, then turn gently till fully open). Underwater, it's not so subtle.

Regarding jammed valves- does this tend to happen with older valves? Any details???

 

[Rainer]

Regarding jammed valves- does this tend to happen with older valves? Any details???

As I said, I've only done it once, and it was quite obviously user error. I really wanted the drill to be over (we'd spent the day doing them and I was "done"). Just took one hard crank and it wasn't coming loose easily. Buddy, however, had little trouble getting it unstuck.

 

[SparticleBrane]

Fully open or fully closed. If you don't want to jam the valve open, then don't -- just open it or close it until it stops. No need to crank on it.

Just like everyone else says, the last thing you need to do is get confused about which way to close it if you suddenly need to.

 

[limeyx]

Just like everyone else says, the last thing you need to do is get confused about which way to close it if you suddenly need to.

true, but we were hammered on in cave 1 "Never go back there looking for an answer. Always know what valve you are manipulating, why you are manipulating it and what direction you need to turn it."

Now I admit things can go to crap pretty easily under stress (which is why its hammered on) and it could be possible to think a jammed valve was either closed or open when it was not (but you should be able to tell by breathing/purging the attached reg for right/left posts)

 

[DeepSeaExplorer]

Fully open or fully closed. You do NOT want to get confused (and it can happen to anyone if stress is high enough).

My first job out of high school was as an apprentice pipefitter and the first thing I learned was to open the valve and then close it slightly, because you don't want someone putting a wrench on a jammed open valve and trying to open it further.

I have to believe that pipefitters know more about valves than scuba instructors, so I still follow that advice to this day, 20+ years later. In a panic situation, you may waste time trying to force open a valve that's already open. On the other hand, if you try to open it and it turns slightly and stops, you know it's open all the way and you can immediately begin looking for other solutions. At 200+ fsw, I've had no problems with reduced regulator performance, that's a red herring argument.

AFAIK, there was one incident years ago where someone claimed the student couldn't breathe due to the valve not being fully open. I've seen this once myself, but it turned out the student had the valve 1/4 turn open, not 1/4 closed, which is a whole 'nother animal.

 

[texdiveguy]

I remember reading somewhere that fully open was correct. Almost everyone I dive with including instructors like to go full and then do the half turn back. Is this still the standard for PADI? I am going through the IDC in a few months, so I am sure it will be covered there.

This is a mistake to 'set' your valve(s) in that manner.....regardless of what PADI teaches you....it is prudent to gently turn your valve(s) on to 'full open' and leave it put till you close it off...very simple and effective!

 

[Ann Marie]

As a PADI Instructor, I teach all my students "fully on or fully off".

 

[Rainer]

My first job out of high school was as an apprentice pipefitter and the first thing I learned was to open the valve and then close it slightly, because you don't want someone putting a wrench on a jammed open valve and trying to open it further.

I have to believe that pipefitters know more about valves than scuba instructors, so I still follow that advice to this day, 20+ years later. In a panic situation, you may waste time trying to force open a valve that's already open. On the other hand, if you try to open it and it turns slightly and stops, you know it's open all the way and you can immediately begin looking for other solutions. At 200+ fsw, I've had no problems with reduced regulator performance, that's a red herring argument.

AFAIK, there was one incident years ago where someone claimed the student couldn't breathe due to the valve not being fully open. I've seen this once myself, but it turned out the student had the valve 1/4 turn open, not 1/4 closed, which is a whole 'nother animal.

So we're in agreement then.