K valve vs J valve

[TwoBitTxn]

Help please...

A J valve is the single knob job that is most commonly seen on aluminum tanks right?

A K valve has two knobs right?

What do the two knobs do?

Why the difference?

Tom

 

[large_diver]

Close -- K valve is the common "one knob" valve you see on most tanks today.

I've never actually seen a J, but have read about them before. See link below for a pic and description.
http://www.diverlink.com/gear/earlygear.htm

 

[Rick Murchison]

The "K" valve is the standard on/off valve commonly seen on most tanks.
The "J" valve has a lever that when raised cuts off airflow at about 300 psi - by lowering the lever you gain access to the last 300 psi. This valve was used before the advent of the SPG as an emergency indicator it was time to end the dive.
The "H" valve has two independently controlled orifices and will accept two first stage regulators. Many will accept both DIN and Yoke regs (via a yoke insert). HP variety are DIN only.
The "Y" valve is like the "H" valve but older, and less common today as the "H" valve can be adapted to a manifold for doubling tanks where the "Y" valve can't.
Rick

 

[The Chairman]

The "Dump Valve" used in the Warhammer Manouver... Unlike the others it HAS to be O2 cleaned for all environments... I almost forgot the Bivalve... which exist on many an ocean floor. And the Valve-salva manouver... Then there's the stuff to lube all of these valves, aka valve-oline. Does anyone still drive a Valvo??? Sorry, just got a bit over in-valved in the process...

 

[Ontario Diver]

Good answer Rick, just let me add a little bit.....

Originally posted by Rick Murchison
The "K" valve is the standard on/off valve commonly seen on most tanks.
The "J" valve has a lever that when raised cuts off airflow at about 300 psi - by lowering the lever you gain access to the last 300 psi. This valve was used before the advent of the SPG as an emergency indicator it was time to end the dive.
The "H" valve has two independently controlled orifices and will accept two first stage regulators. Many will accept both DIN and Yoke regs (via a yoke insert). HP variety are DIN only.
The "Y" valve is like the "H" valve but older, and less common today as the "H" valve can be adapted to a manifold for doubling tanks where the "Y" valve can't.
Rick

Most rental "J"'s have been modified to remove the lever action and function just like a "K".

The names come from the item numbers that were used to identify the valve in the early catalogs. (A "L" valve was item L; the "K" valve was item K, etc.)

 

[TexasMike]

Pete....

And in one way(valve), I always keep the butterfly(valves) close to my heart(valves).


Sorry...couldn't resist the very obvious pun(valve).

 

[The Chairman]

I think I o-puned a can of worms... yeah, yeah, I know I am one to puntificate... remember I valve-u our friendship, so I will be quiet now... As Vince Lombardi once said... "When in doubt, Pun!"

 

[TwoBitTxn]

Ok I think I understand, but I'll try to describe what I have and get some one to explain what I got.

I picked up a tank that has a knob on one side that is obviously the on/off. It has another knob 180* from it with the port in the middle. What do I have and what does the other knob do?

The tank needs a hydro and is empty. So I can't fill it to find out.

Tom

 

[miked]

Tom,
This is a semi-wild, semi-educated guess, but you might have a "J-valve" ,with function as accurately described by Rick.
Does the knob opposite the "on /off" knob have anything that looks like an attachment point for a hook ended rod?(a small hole or "eyelet"?)If so, that would be a stronger indicator that you have a "J valve". I also remember being told that the "other" knob was there for ease of carrying- but that always sounded a little strange, as we were simultaneously being told to not carry the tank by the valve.

OD, I hadn't heard the "catalog" source for the names of the different type valves before this. I recall being told that the J valve got its name from the shape of the rod used to activate the reserve PSI in the tank, and that the "Y valve" and "H valve" were so named because of their shape. (I must confess, I've never seen an H valve, so I can't judge the accuracy of that part of the claim.)
In any event, its interesting how these different interpretations occur.
Take care,
Miked

 

[The Chairman]

A "J" valve. The knob (usually on top) opens the tank valve, the other lever (which only goes so far) is the "safety mechanism". That being said, if the tank hydros out, I would replace that valve with a newer "K" valve. BTW, the story about the catalogue is true for the H, K, and J valves... the Y get's it name from it's shape.