Quiz - Equipment - J-Valve

[rhwestfall]

This question is like asking what leaded gasoline is used for on a current driving exam.

Except that there are certain types of diving that regulations still require its use (no-vis).

 

[Manatee Diver]

E: Find out that somehow that level got pulled down and now you are truly out of air.

 

[Pedro Burrito]

E: Find out that somehow that level got pulled down and now you are truly out of air.

I started off with the J-valve and developed the J-valve twitch where I was regularly checking that it had not been pulled down by something. Most of my early dives were 30 minutes because I never knew how much gas I had and I did not like to wait until I needed to pull it down.

 

[AfterDark]

I started off with the J-valve and developed the J-valve twitch where I was regularly checking that it had not been pulled down by something. Most of my early dives were 30 minutes because I never knew how much gas I had and I did not like to wait until I needed to pull it down.

Me too and years later when I went back to a DBL hose for picture taking and used a J valve I found that I still had that J-valve twitch! Now I have a banjo fitting for the DBL hose.

 

[scubadada]

I started off with the J-valve and developed the J-valve twitch where I was regularly checking that it had not been pulled down by something. Most of my early dives were 30 minutes because I never knew how much gas I had and I did not like to wait until I needed to pull it down.

I also checked frequently, never got pulled down accidentally. I dived frequently in the California kelp and heard stories of accidental opening

 

[Ukmc]

I am a little young and inexperienced and never dove a j-valve, although learned about it enough to know how it works. I understand why it was used in 50-60-70’s but why would anybody use J-valve nowadays? Is this for situations when the visibility so low you can not read your depth gauge or a computer? Or is this a historical question?

 

[d^2b]

For some reason at first my brain refused to accept "having your air cut off" as a "warning mechanism". Shows how soft I am .

 

[James79]

I am a little young and inexperienced and never dove a j-valve, although learned about it enough to know how it works. I understand why it was used in 50-60-70’s but why would anybody use J-valve nowadays? Is this for situations when the visibility so low you can not read your depth gauge or a computer? Or is this a historical question?

Exactly, the zero vis type dives. I am starting to use them out of curiosity and to work my way towards true vintage. So there is a market/audience for them, albeit a small one.
Respectfully,
James

 

[scubadada]

For some reason at first my brain refused to accept "having your air cut off" as a "warning mechanism". Shows how soft I am .

Air was not cut off, breathing resistance increased and you knew to pull the lever and ascend . In those days, ascent was 60 ft/min and there was no safety stop. Using a steel 72, filled to 2450 psi, my ascent took less than 100 psi from as deep as 130 ft. I only dived a J valve for a couple years/around 50 dives, before I bought a SPG.

A contemporary ascent at 30 ft/min with a 3 min SS would take me a little under 250 psi, could still make it starting at 400 psi, but not with much leeway

 

[tursiops]

My J-valve usage was in New England. We'd descend, take off each other's pull-rods, use them for (illegal) tickle-sticks for lobsters, then put them back on before surfacing. Our OOA plan was to reach back and push the lever down. I can't believe now that (1) we were so stupid, and (2) I could actually reach that lever in the full 7mm farmer-john that was a bit small.