Quiz - Equipment - J-Valve

[Altamira]

Understood.
Also agree that I may have gone to 100' back then with a J valve if it was set to a higher break value.
Thanks, now I know exactly where the " keep 100' PSI for every 10' you have to ascend" (ie. 1000 for 100') comes from.
So, if you are another who would plan to use the air the J Valve releases as part of your ascent plan (though not if it releases only 300 PSI), this leans me more toward not calling that gas "extra".
The Cousteau writing and the 1968 article explain what the valve is and does and how it works (we all know that). They don't explain if it was intended to be used on every dive or not.

Dove a U.S. Divers steel 72 with J-valve and a single hose Voit Avalon regulator from 1965 to 1974 in both OW and overhead environments. When in an OW environment, we would routinely use the J-valve on ascent from medium depth (40-50ft) or while playing around in the shallows. We were always out of the water before any OOA situations. However, when in an overhead environment, which was most of our diving, we never planned or used the J-valve for anything other than an emergency. In overhead environments, if we had to pull the rod, we would have seriously screwed up our dive plan. We were ultra conservative divers, so that never happened. It is also important to remember that back in the day, if you had to share air, it was buddy breathing, not sucking on an octo, so we would not be down at 90-100ft anywhere close to having to use the J-valve for ascent.

Edited to add: Also, our fill guy was a man who filled the fire department's tanks, and he would routinely fill our tanks to 2600 psi without us even asking for a 10% overfill.

 

[TMHeimer]

Dove a U.S. Divers steel 72 with J-valve and a single hose Voit Avalon regulator from 1965 to 1974 in both OW and overhead environments. When in an OW environment, we would routinely use the J-valve on ascent from medium depth (40-50ft) or while playing around in the shallows. We were always out of the water before any OOA situations. However, when in an overhead environment, which was most of our diving, we never planned or used the J-valve for anything other than an emergency. In overhead environments, if we had to pull the rod, we would have seriously screwed up our dive plan. We were ultra conservative divers, so that never happened. It is also important to remember that back in the day, if you had to share air, it was buddy breathing, not sucking on an octo, so we would not be down at 90-100ft anywhere close to having to use the J-valve for ascent.

Edited to add: Also, our fill guy was a man who filled the fire department's tanks, and he would routinely fill our tanks to 2600 psi without us even asking for a 10% overfill.

Another vote for "emergency" use only (at least on deep dives). Another case of "extra" IMHO.

 

[GrumpyOldGuy]

My first tanks had J valves, I think I only had to pull it a couple of times. Was actually a good reminder I was being young and stupid, losing track of my air. It was however a low profile error compared to the honking ScubaPro regulators that some other divers were using. Those were screaming to everyone in earshot that a diver was being stupid.

 

[TMHeimer]

I just noticed 68.3% got the "wrong" answer voting "d". Tells you something.

 

[tursiops]

I just noticed 68.3% got the "wrong" answer voting "d". Tells you something.

And the chances are that more than 68.3% have never dived with a J-valve.
You are getting a bit tiresome with your relentless attempts to not be wrong with your answer.

 

[ToneNQ]

And the chances are that more than 68.3% have never dived with a J-valve...........

I have filled J valve tanks, never dived with them. Even my Dad has never dived J valves, he had the regulator that rattled with declining pressure.

The Scubaboard demographics would tell a story. What if 5% actually knew the answer from experience? The other 18% thought back to their OW course, or thought through the principles well, or guessed right.

 

[TMHeimer]

And the chances are that more than 68.3% have never dived with a J-valve.
You are getting a bit tiresome with your relentless attempts to not be wrong with your answer.

I know my answer and that of all those others is wrong--according to the answer key.
I acknowledge I'm getting tiresome with my attempts to point out the unclearness of this question,
and apologize for that irritating you.
I think most of the 68.3% that voted "d" are well aware of how a J Valve works without having dived one, since it would seem to be explainable in one sentence. You pull the pin, it releases the air. Not rocket science.

YOU have been relentless with your point of view that it is not "extra" air. I have maintained it is not what you call that air that matters-- that is semantics, and doesn't matter to the average diver who takes this test, thus all the wrong answers.

I may be off base, but I't seemed you were referring to me as being a PADI basher way back at the beginning of the thread (if I'm wrong, please accept my apology). I am simply pointing out that this is the only question where a large majority got it WRONG. And that maybe, just maybe, those responsible at PADI could have worded it clearer.

Your point of view about the word "extra" means you feel the question is clear.
I feel it is unclear.
We simply disagree. As do maybe 68.3%?

 

[scubadada]

OK, I could not stand it anymore. When a test question is written, it is validated with the population being tested. It is expected that a reasonable majority of educated test takers will get the question correct. That is certainly not the case with this question, where only 24% got the question "correct". I was initially trained on the J-valve and dived it for 2 years before I purchased a SPG. I also got the question "wrong" by choosing d as the correct answer. Apparently, you cannot breathe the tank down without pulling the J-valve, it gives you additional gas, not available otherwise. For me, the correct answer will always be d. Perhaps this is just a poorly written, unvalidated question, that would not be surprising to me. You can argue it any way you want...

 

[Altamira]

In the grand scheme of diving knowledge, the test question and the PADI answer are really unimportant. What is important, is that divers that have used, or use, a J-valve understand how the valve functions. The "word smithing" of the answer depends on a diver's interpretation of the question rather than understanding how the valve works. Furthermore, I'll bet few people on this board have ever seen, much less used a J-valve, and if you look at the general diving population, the percentage of people that use, or have used, a J-valve would drop into the low single digits. BTW, I also got the answer wrong despite diving the valve for nine years, and I have not lost a moment of sleep over my "failure."

 

[James79]

In the grand scheme of diving knowledge, the test question and the PADI answer are really unimportant. What is important, is that divers that have used, or use, a J-valve understand how the valve functions. The "word smithing" of the answer depends on a diver's interpretation of the question rather than understanding how the valve works. Furthermore, I'll bet few people on this board have ever seen, much less used a J-valve, and if you look at the general diving population, the percentage of people that use, or have used, a J-valve would drop into the low single digits. BTW, I also got the answer wrong despite diving the valve for nine years, and I have not lost a moment of sleep over my "failure."

I agree, and more-over, pedro-burrito posts these to help keep us engaged.... Technically right or not, the question caused people to learn how a j-valve works and how it is used. I call that a success!