Will an older 72 cu. steel tank take a modern K regular valve?

[rob.mwpropane]

I have several Norris tanks - which those seem to be. They are either the teflon 1/2 tapered or normal K valves (3/4) valves. Is that valve smaller than a normal valve? As 2TH DIVR mentioned - it does look like a Healthways 1/2 straight valve like I have for a old WK, but didn't know Norris used those.

They did not have teflon when I took them apart, but that doesn't mean much. They're 1/2" of some sort, a good bit smaller than 3/4". They do not look tapered to me, but I don't own any tapered ones to compare to.

Attached is 3/4", then 7/8", then whatever these are.

 

[NW Dive Dawg]

On the burst disc, you're not going to find the "right" burst disc for them, so use a 2400psi service burst disc for it which is what is on modern low pressure steel tanks

Just curious. For all you guys and gals that use what is commonly know as "cave fills"...... do you also intentionally install a burst disc that has a higher rated "burst" pressure ?

 

[tmassey]

Just curious. For all you guys and gals that use what is commonly know as "cave fills"...... do you also intentionally install a burst disc that has a higher rated "burst" pressure ?

You do if you want the gas to stay in the tank!

There’s a couple ways people handle that. They either install a burst disk larger than the pressure that they want to use in the tank, or they intentionally disable the burst disk. Back when most burst discs were separate assemblies where you had to handle the thin copper piece yourself, people would intentionally double them up. The nice thing about that is you get plausible deniability. “How did that happen? I have no idea!“

The fun part is when you forget about valve ratings and get a set of tanks that you use for cave fills and you don’t change out the burst disc…. If you’re lucky, it’s just a bit of a loud bang that quickly reminds you of your oversight.

 

[NW Dive Dawg]

I get it.... It's like putting a copper penny into a fuse box instead of using the fuse that was intended for safety... My dad would do this in the olden days if the power went out and the hardware store was closed. Glad we never burned the house down.

 

[Tracy]

Any idea what these are? I was planning on cleaning them up until I saw the threads. Now I'm not sure.

1/2"NPS
Those are cool. Not useful cool, just cool.
I actually don't have any of them. If you want to part with one, it would be nice to have around for teaching VIP courses.

 

[Jim Lapenta]

Just curious. For all you guys and gals that use what is commonly know as "cave fills"...... do you also intentionally install a burst disc that has a higher rated "burst" pressure ?

I had 4K discs in all of my steel LP cylinders. Most of those have been sold now. The last two 72s with 3/4 neck valves have 3200 discs in them.

 

[2airishuman]

They did not have teflon when I took them apart, but that doesn't mean much. They're 1/2" of some sort, a good bit smaller than 3/4". They do not look tapered to me, but I don't own any tapered ones to compare to.

Attached is 3/4", then 7/8", then whatever these are.

Quite possibly M18. I encountered an older tank with that thread form once.

Amazon has them. No idea what the quality is like. Be sure it truly does fit properly, natch, valve ejection accidents suck.

www.amazon.com/TUXING-4500Psi-Scuba-Diving-Valve/dp/B0BLZ2VTQ9

 

[rob.mwpropane]

1/2"NPS
Those are cool. Not useful cool, just cool.
I actually don't have any of them. If you want to part with one, it would be nice to have around for teaching VIP courses.

For you Sir anything. If I can't really do anything "useful cool" with them then they're yours.

My dream was at some point to build a set of 72's for shallow dives,but I guess these ain't it. Shame as they are pretty.

 

[James79]

For you Sir anything. If I can't really do anything "useful cool" with them then they're yours.

My dream was at some point to build a set of 72's for shallow dives,but I guess these ain't it. Shame as they are pretty.

I have a 1/2 NPS tank and dive it regularly....if the tanks pass hydro and vis, there's no reason not to put them in service. I even acquired a spare valve to rebuild as a standby in case the one in it ever gets beyond rebuilding.
Also, if the J valves mechanism is good then it is still a viable backup/emergency reserve (I seem to recall you mentioning diving in muck/terrible vis).

Respectfully,

James

 

[rob.mwpropane]

I have a 1/2 NPS tank and dive it regularly....if the tanks pass hydro and vis, there's no reason not to put them in service. I even acquired a spare valve to rebuild as a standby in case the one in it ever gets beyond rebuilding.
Also, if the J valves mechanism is good then it is still a viable backup/emergency reserve (I seem to recall you mentioning diving in muck/terrible vis).

Respectfully,

James

They do not have the j valve anymore (which I've never seen in person so I don't even know what that looks like). They look like great tanks, maybe if I didn't have so many already? The insides look exceptional.

I have one 3/4" LP72, I guess I need one more to double up for a set. It's just a pipe dream anyway, I should be content with what I have!