J valve

[mfalco]

A formor diver I know was cleaning out his basement and gave me th 4 tanks he found.

2 of them have J valves. When I get the tanks inspected, should I have the valves replaced with K valves, or is there no point?

 

[pescador775]

The valves (all) should be taken apart for inspection and O rings (older valves probably have one or more) replaced. There is nothing intrinsically wrong with a J valve. Typically, today's diver uses a gauge so the valve would not be placed in the reserve position. When filling, the reserve arm must be down. J-valves should be inspected and checked for leakage around the gland underneath the lever arm. Like the control knob, this is done by removing the knob and bonnet. It would be a good time to clean everything with special attention to removing old lube and replacing with Christolube. The cost may amount to nearly as much as the price of new, discounted valves unless you do the work yourself.

 

[oly5050user]

really no point in it..just dive with the reserve in the down position..new valves can run $40-$60..after hydros/vip you may spend a total as high of $110.At that price it may be better to buy a new one..I sell new (vip inc. at no charge of course) alum 80 at $225.. but that includes 20 air fills(at $8. a fill thats $160.) not counting the fill the tank came with,so thats 21 fills. So new tank cost actually $65..Think of it as pre paying some fills..

 

[Tom Winters]

There are lots of great used Sherwood 5000 K-valves floating around in the $10- to $15- range since so many people have converted to DIN/K or pure DIN valves. I had 4 that were not even worth the trouble of eBaying so I tossed them.
Don't spend any time or money on J-valves unless it's as an historical artifact. I just got one that's 51 years old - the tank it's on was manufactured in May, 1955, and it's the tank I taught myself to dive with in 1961.
That one I keep for a while until it goes to the frogman museum in PCB.

 

[dhampton82]

Are the tanks AL or steel that have the J-valves on them?
If they are Aluminum, then the valves will probably be the least of your worries

 

[Nemrod]

By the time aluminum tanks came along the era of the J valve had mostly passed, very few aluminum tanks would have J valves and while I am sure there were some made--no J valves that I have seen have been intended for 3,000 psi service, though many do well at that pressure. N

 

[Luis H]

Hi Nemrod

You forget US Divers started pushing aluminum tanks around 1971. First with was the 72cuft that was stamped with a working pressure of 2475 psi (what a floating buoy that thing was). Then (still in the early 70’s) they introduced the 80cuft 3000 psi aluminum “professional” tank.

All through the 70’s and the 80’s (I don’t know about the 90’s) USD was selling aluminum tanks with J valves. One of my LDS has a bunch of rental aluminums with USD J valves.


My understanding is that USD (Aqua Lung) has never actually totally discontinued their J valve. A new J valve is probably hard to obtain and probably expensive, but I think they are still available for commercial divers. My understanding is that OSHA (and maybe the NAVY) requires them for zero visibility dives.


Personally, I hope the OP got some good steel 72 tanks. The J valve is no issue. Just don’t use it.

 

[james croft]

Luis,
You are correct on the Navy and commercial applications for the j-valve. They are currently available and are currently in service. They are required in o viz. I have a bunch of these tanks, some of the tanks were recently made in the past couple of years. They are for 3000 psi tanks. The j valves may be brought from any company catering to commercial operators. Mar-vel is an example.

 

[pescador775]

All in all, the correct answer for you is probably to discard the J valve and maybe the others. Get some Ebay specials. Figure about $30 ea for new valves. The USD J valve, the shiny, chrome low boy, uses a teflon washer inside the bonnet. Those little rings may need replacement and could be difficult to find. There are other parts which might need attention as well.

 

[Nemrod]

Your right Luis, I just don't remember seeing them much on new tanks after about 1970. I know the shops I worked in did not stock them on aluminumt tanks but I believe you that there were some and may still be for commercial use.

Take Dacor for example, I have some of their metal wheel valves, some are LP and some are HP and the only difference I see is that the ones that were set up for LP use have the old style fat O rings and the ones that have the HP service decal have the little skinny O ring. I have used both at well over 3,000 psi with the correct burst discs for that pressure and they do fine.

If the tanks the fellow found are relatively unused those valves may be just fine for years of use AND, good steel 72s are so desireable they are worth investing in new valves if need be or servicing of older valves--assuming that is what he was given.

N