Quiz - Equipment - J-Valve

[Pedro Burrito]

From the PADI Dive Theory Exam:

When used as designed, a J-valve will:

I will post a daily question from my exams to help newer divers and to encourage more experienced divers to interact gracefully and helpfully with the newer divers.

Reminder - this is a post in the Basic Forum and it is a green zone. Please be nice and on topic.

Thank you for your patience while we try to give people something to discuss other than Covid-19 and/or Politics. I will post the answer covered by the spoiler tag later today.

 

[jadairiii]

My first tank had a j-valve!

 

[Doc]

And the follow-on question:

Why is it called the “J Valve” ?

 

[BlueTrin]

And the follow-on question:

Why is it called the “J Valve” ?

It was the letter for catalogs ?

 

[Scuba-74]

It was the letter for catalogs ?

Yep. Nice bit of trivia I learned from Mr. Peirce.

 

[scubadada]

And the follow-on question:

Why is it called the “J Valve” ?

US Divers catalog in the 1950s had the valve with the reserve labeled J and the valve without the reserve labeled K, still called the K valve.

Having dived a J valve for 10 years from 1970-80, this was an easy question for today's quiz

 

[Angelo Farina]

My 15 liters single tank (Cressi) is still equipped with the reserve and dual post.
However I usually keep the reserve valve open since the beginning of the dive.
The reserve is set at just 50 bars, which I always considered not safe enough...

 

[Jcp2]

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

 

[broncobowsher]

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

The boat gets 100 octane LL from the local airport, the motorcycle gets 110 octane Sunoco from the gas station across from the race track. Depends on which driving exam. The motorcycle has my riding ability's scored nearly every time I ride it.

 

[scubadada]

My 15 liters single tank (Cressi) is still equipped with the reserve and dual post.
However I usually keep the reserve valve open since the beginning of the dive.
The reserve is set at just 50 bars, which I always considered not safe enough...

When I got a SPG in 1972, I found that my J valve activated at around 400 psi, a little below 30 bar. After I had the SPG, I also dived with the reserve open