Name These Valves?
- Thread starter sarita75
- Start date
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Green_Manelishi
Contributor
sarita75:
Interesting is not a word I'd use to describe a J-valve. Did your lessons not ever mention such a beast?
Jimmer
Contributor
Did you never see J valves in your OW course?
Those are J-valves- I believe they were around before the SPG, so they have a built in reserve. When the tank was hard to breathe, the diver would pull a lever attached to the extra valve (on the left in your picture) and this would release the reserve so the diver could begin the ascent.
Some shops still have them and they should work just fine. Since you probably have an SPG, if you use the tanks, leave the reserve in the down position (and I believe they fill that way too)
Some shops still have them and they should work just fine. Since you probably have an SPG, if you use the tanks, leave the reserve in the down position (and I believe they fill that way too)
Yes, J-value. Haven't been in regular use for years.
Steve
Steve
That yellow tank might be as old as you are- I looks like the original hydro date is 3/75, although it's hard to see in the picture. The yellow one also has the 3AL overstamp- all the XXXXXX and 3AL which makes it older than Walter!
Jimmer
Contributor
Yeah, you need to keep them down to fill...so basically just keep it flipped down all the time. The only downside to them is some of the older ones can start to cause problems and they can be a bit of a PITA to have serviced. As long as they are still moving free and don't cause any problems, then you have nothing to worry about.
Jimmer
Contributor
divermatt:Hey everyone. They don't mention J valves anymore in training, at least not in my OW or AOW class. Can you just get new valves? I don't have J valve tanks, just too much curiousity.
Sure you can just replace them. Most (if not all of them) would be the standard 3/4" NPSM threads, so finding yoke K valves to replace them would be very easy and probably pretty cheap. I think I saw someone on here selling 2 for $25 recently. I'm still a little surprised that they don't at least mention J valves, if nothing more than "keep the left side flipped down".
Yeah, you can get new valves. Alot of people sell used yoke valves when they move to DIN. I believe most "modern" tanks use the same threading, the only odd ones are HP steel and they might use the same now too, but I think some use a different, smaller, tapered thread.
The only problem you will have is the 6351 alloy, SLC. Some shops might refuse to fill the tanks. Remember: Catalina never used 6351, so if they are Catalina, you are probably good to go. Still, alot of shops give you flack and for good reason (in some cases). If you want to know more about that,s earch on it, it's one of the most discussed topics on here.
And again, those are J valves. The modern valve is a K valve. There are H valves, and Y valves also, but the K are most common among rec divers, H is the newer thing to replace the Y valves. J and K come from the old US Divers' catalog, they were items K and J respectively. Y valves look like a Y, and H valves look like an H.
And the "reserve" isn't a special "tank in a tank" kind of thing, basically the valve has a spring and some stuff so around 500-700 psi it'll close off, making it hard to breathe. You turn the valve knob to re-open the airway, and ascend. It basically let you know when you go down to 500-700 psi. It is not very reliable, maybe it goes off at 200, or maye at 1500, who knows on old stuff if it's not been taken care of. To use these now, just leave it on the "off" position, so you have no "Reserve."
The only problem you will have is the 6351 alloy, SLC. Some shops might refuse to fill the tanks. Remember: Catalina never used 6351, so if they are Catalina, you are probably good to go. Still, alot of shops give you flack and for good reason (in some cases). If you want to know more about that,s earch on it, it's one of the most discussed topics on here.
And again, those are J valves. The modern valve is a K valve. There are H valves, and Y valves also, but the K are most common among rec divers, H is the newer thing to replace the Y valves. J and K come from the old US Divers' catalog, they were items K and J respectively. Y valves look like a Y, and H valves look like an H.
And the "reserve" isn't a special "tank in a tank" kind of thing, basically the valve has a spring and some stuff so around 500-700 psi it'll close off, making it hard to breathe. You turn the valve knob to re-open the airway, and ascend. It basically let you know when you go down to 500-700 psi. It is not very reliable, maybe it goes off at 200, or maye at 1500, who knows on old stuff if it's not been taken care of. To use these now, just leave it on the "off" position, so you have no "Reserve."
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