The Dangerous 1/4 Turn

[nikeajax]

Here's Dave's link...

[surflung]

- What a neat video. I met Alec Pierce at the recent Sea Hunt Forever show in Silver Springs. He had a booth set up with all kinds of Sea Hunt TV Show memorabilia. He also judged the Mike Nelson look alike contest and obviously had a lot of fun doing it. I was so proud that I had a Sportsways depth guage like Mike Nelson. Then in judging, Alec says, "I see you have the Sportsways gauge but I'll have to take off some points because you have the 150 ft model and Mike Nelson wore the 75 ft model."

- The video has a neat bit of history in showing where the "K", "J" valve distinctions came from.

[nikeajax]

So Eb, wha'd they give ya fer winnin' he contest, somethin' swell I hope

JB

[diverdon]

Thanks for that link JB! I too got meet Alec at Legends in '14, great guy. I'm going to have to see if he has more videos out there.

DD

[red]

Well, I did something horribly unprofessional and very practical this week. I traded in my farmer johns for a proper neoprene kilt and sporran.

No, really. Almost as bad, I bought a "Vindicator" (VIsual iNDICATOR) valve handle and forced my classic J valve to wear it. Online for for a whole $15 and change so I said "WTF".

And you really do have to read the fine print to install it really properly, but when you have the red and green collars aligned properly, it gives a very clear RED BAND showing when the valve is closed, and a GREEN BAND totally covers that when the valve is open.

I could have Maggie Simpson playing divemaster and even SHE would have a hard time screwing that up. And when I'm hot, tired, dizzy, and just plain out of it (what, everyone doesn't dive that way?(G) I can see my tank from ten feet away and clearly tell if the valve is open or closed.

No so professional, not so elegant, and not as compact, but as I said, "WTF?" it makes a simple and robust safety check that tells me the valve is FULLY open or closed.

[george]

This past Friday I did a Maggie as well I sure wish I had had one of those valves. I had a leak when I turned on my tank with my DA on line, I turned it off found the problem and turned it on ever so slightly to make sure it did not leak anymore. Well I got to doing something else and forgot to turn it all the way on, needless to say at 75 feet I said to my self this DA sure is breathing hard , came back up to 30 feet for the rest of the dive ( 45min) and got out gear off and low and behold the valve was just barley on , so there you go!

[red]

George, the hardest part of putting it on is to realize you need a tank valve knob tool, or a notched straight screwdriver, or a needlenose plier, or something similar to unscrew the nut that holds the knob on.

After the meltdown at Three Mile Island, the nuclear plant industry went to using BEER TAPS as an off-the-shelf way to make sure people didn't pull the wrong lever. You know, if they are all black...much easier to tell them apart when one says "MILLER" and the other says "BUD" and they are both different colors, heights, and shapes. Sometimes, it really is that easy to avoid a bad day.

[SeaRat]

Red, what you are doing is highly recommended by safety professionals and industrial hygienists. I worked for many years in these fields, and the discipline is called "ergonomics." Displays and controls are a part of this, and these visual indicators and one of the best controls for our problems of slightly open valves. Here is where, on Amazon, these "Vindicators" can be purchased.

www.amazon.com/Vindicator-Visual-Indicator-Scuba-Cylinder/dp/B00COC4C6A

You can probably get a slotted screwdriver from Herman too, making the changeout very easy.

John

[red]

Hi John. I always thought ergonomics was the field of making things work well with the human body, i.e. the proper height for a desk, for your chair, for your keyboard and the appropriate slant of it, all that physical stuff. There's a different term, which I'm having a senior moment with, to deal with "human interface" making things work better in other ways than the physical ones. "Good human engineering" is one name for it.

If you set up two valves, or switches, such that physically they block each other form both being engaged at the same time (when only one should be engaged at any time) that's not ergonomics, that's just good engineering.

Putting the valve on the front of the BC, that would be good ergonomics. And a bit frail, or expensive, from the engineering point of view. (G)

Now, if the scuba industry would speak to the SAR industry, and get it through their thick skulls that SMD's are simply not as effective as bright colored BC's....little things like SOLAS standards exist as a result of, literally, post-mortems after accidents on the water.

[SeaRat]

Hi Red,

Actually, ergonomics is all-encompassing, and includes human factors engineering. I have a classical ergonomics book, Ergonomic Design for People at Work, printed by the Human Factors Section of Eastman Kodak Company. Mine was published in 1983, and it has since been revised. But it has a whole section on visual displays and controls. The field of ergonomics has to do with all the ways that humans interface with their work environment. It includes workstation ergonomics, as you stated, but that is a very small part of it. This was recognized in the very early days of WWII when we lost pilots due to the layout of their plane's controls. It has progressed into the space age, where vibrations have to be contended with during liftoff and inadvertent spins while is space (Gemini VIII). And, it includes diving, where tech divers sometimes exhibit horrible ergonomic configurations, with pure oxygen and redundant systems being mistaken, one for the other. This, in a slightly different context, resulted in the death of diver Peter Small during Hannes Keller's record 1000 foot dive, where he inadvertently opened the wrong valve and got the wrong gas mixture at depth. The field of ergonomics includes human factors engineering, but also includes things like how protective clothing affects the worker/diver/astronaut/pilot physiologically. For this thread, ergonomics would include how to recognize that a scuba tank is only slightly on, verses all the way on, and this new valve handle, the Vindicator, does this well.

John

[vance]

When I was a Machinist's Mate in the USN, we were taught to open valves all the way and crack it back. Not necessarily a 1/4 turn, but back it off from fully open. No explanation other than it shouldn't be jammed open and leaving a bit of slack is good. We were told that's the right way to treat ANY valve. It's the way I still treat any valve. Subsequent stints as a car mechanic and machinist put me in the company of many others who insisted on the same procedure. Since I'm using an old 1/2 inch K valve, that's still what I'll do.

[red]

Sitka-
This is why some folks say "I know better than to do that" while others, including professional "human interface" engineers, DESIGN systems that simply are more idiot proof. In the knowledge that, historically, the gods have always had more time to design a better and larger grade of idiots. (Or simply tired and confused people.)
Which is why I replaced my tanks valves, which I originally heat-engraved "OPEN-->>" and "CLOSED-->>" on the appropriate sides of the face) with the new and terribly named "Vindicator" (Visual INDICATOR, get it?) valve handles. When the tank valve is open, there's a big green ring exposed that can be clearly seen from across the boat. When the valve is closed, there's just a RED ring instead. Under $20 and simple DIY installation, in a variety of knob colors to help clarify gas mixes as well.
Have I ever made that mistake? No. I did have to rescue a buddy who made it though. Partly my bad, my peers never did the "cross check your buddy's gear" thing, because that would mean touching their gear, which could mean tampering and screwing it up as well. I don't mind EYES on my gear, but I don't want PAWS on it, for any reason.

Or we could have the regulator first stages redesigned, to be like the CNG or hydrogen car filling hoses. Snap on, snap off. No pesky manual valves involved at all. Which would be a great reason to have a new PADI Advanced Safety Valve Operator's Card Course, too. (sigh)

[vance]

But, even with the vindicator, you don't have to stress the valve by cranking it hard open! Backing off from the tight end of the travel a bit to a tiny stress relief can't hurt, and may just save someone under some extreme condition. You guys know what it feels like to open a valve to its limit. It's stuck! Then, just back off a bit. Common sense....

[nikeajax]

Oct 26, 2016 16:52:25 GMT -8 vance said:

But, even with the vindicator, you don't have to stress the valve by cranking it hard open! Backing off from the tight end of the travel a bit to a tiny stress relief can't hurt, and may just save someone under some extreme condition. You guys know what it feels like to open a valve to its limit. It's stuck! Then, just back off a bit. Common sense....

This, in my opinion, is good practice with 60+ year old K-valves. I've worked on enough antique faucets to see what years and years of opening and closing does to the brass: again this is just my opinion and don't expect ANYONE to agree...

JB

[red]

Agreed, and agreed. And even more so, if you've learned to always back off a valve handle slightly, to prevent it from freezing it or being jammed, that becomes "muscle memory". You don't think about it, your hand just does it that way ALL the time. And that consistency means you WILL do it with the valves that really need it, like old valves, or gate valves.

The Vindicator? (And I hate that name for this product!) I call it cheap insurance against Homer Simpson Moments. D'oh!