Tank valve knob lock?

[WetSEAL]

As a beginner diver, it makes me a little nervous thinking about my tank valve knob, being out of sight, which could either be bumped (perhaps repeatedly, eventually causing it to become closed), or potentially ensnared in some line/netting/etc such that my movement closes the valve...cutting off or restricting airflow, and/or causing the yoke to lose pressure which could then also lead to the regulator becoming disconnected from the tank.

I watched a movie (don't remember which) in which something like this happened to a scuba diver as they were entering a wreck when they bumped their tank valve knob on the wreck, creating an emergency situation.

It would seem to me that it would be pretty simple to design a valve that could be locked open, to prevent it from being accidentally closed. Even if this is a low probability scenario, it just seems like it would be a good additional safety feature, so I was a little surprised when my search results didn't turn up anything. Does something like this exist? If it doesn't, why doesn't it?

 

[tbone1004]

@WetSEAL equipment solution to a skills problem. Put your tank up higher so you can reach it.

We could put SCBA style locks on there, but there isn't much of a point and you'd have to redesign the valves anyway since there would have to be a metal lock tab for the valve to lock onto.

 

[soggybadger]

Upside down tank?

 

[tridacna]

Solution to a problem that is non-existent.

 

[Doc]

A)
No redesign necessary.

Drill a hole through the rubber portion that you turn the valve with. Cable tie it across the stem.

Or did you want to use a locker combination type or maybe a Titanium Master Lock? Design something, rent a booth at DEMA, win the annual prize that I award for the funniest piece of dive gear.

As above, skills: be able to reach the valve right from where you happen to be SCUBA diving.

And B)
Believe nothing you see in the media, including Sea Hunt. If you did, you'd surely be breathing from Oxygen tanks.

Go diving, keep learning, it will all work out.

 

[WetSEAL]

Solution to a problem that is non-existent.

I explained a scenario that seems plausible to me and would lead to a pretty serious emergency. What leads you to say that this potential failure point is not worth considering?

A)
No redesign necessary.

Drill a hole through the rubber portion that you turn the valve with. Cable tie it across the stem.

Interesting idea, although that would be a hassle to remove probably requiring a knife. I was imagining more of like a twist open followed by folding down a separate tab or something to lock in place.

@WetSEAL equipment solution to a skills problem. Put your tank up higher so you can reach it.We could put SCBA style locks on there, but there isn't much of a point and you'd have to redesign the valves anyway since there would have to be a metal lock tab for the valve to lock onto.

While being able to reach an accidentally closed valve in order to re-open it is better than not being able to reach it, I'd rather not have to worry about the possibility of the valve being accidentally closed while underwater at all...

 

[The Chairman]

I explained a scenario that seems plausible to me and would lead to a pretty serious emergency. What leads you to say that this potential failure point is not worth considering?

I've been diving since 1969 and this has never happened to me. However, if I'm in a cave and hear/feel my tank bump the ceiling, I reach back on both sides (double tanks) and make sure that they are open. In case of a free flow on one of my regs, I want to be able to isolate that reg off. No, you can't do this with only one tank, but you could feather the tank open/close with the offending reg in your mouth. You can't even do that if it's locked open.

 

[tbone1004]

@WetSEAL it's not worth considering because reaching back and turning it back on is super easy and the odds of it going in a wreck if it were all the way open are essentially 0. In a cave it happens in doubles relatively frequently but how often are you in an overhead environment rubbing your tank against the ceiling?

Do me a favor. Go turn a tank valve all the way on and count the revolutions that it has to make to actually roll all the way off *hint, it's a lot*. If you open your tank valve all the way, which you should because a quarter turn back is retarded and unnecessary, then the only time that you should have to worry about a roll off is in a cave or serious wreck penetration when you have doubles. If you have doubles it's a nonissue because you can reach the valve knobs and turn them back on, as well as have an independent regulator that is easy to get to.

 

[divad]

Solution to a problem that is non-existent.

But you obversely digress. Or is it digress obversely?

 

[divad]

Yes, but I agree.