Tank Valve IDs and Max Fill Pressures

[Aquanaut2000]

I was wondering why our LDSs weren't filling our tanks as much as we wanted and found out that there are many odd tank and valve combos that cross the shop's path. I've got two tank valves that I'm not sure of on my tanks. Can anyone ID them and I'll search up what max pressure (bar) they are rated to?
Many tanks

 

[rjack321]

Will depend on the burst disks installed, which I'm guessing are ancient since CIG was acquired by Luxfer in 1996.

Otherwise yoke valves are 206 bar / 3000psi. Getting short fills has nothing to do with the valve. They look like old sherwood valves but that isnt your issue

 

[Aquanaut2000]

The burst disk on the 'sherwood' valve says 36mpa. Funny thing is the burst disk on my high pressure sea hornet 230 bar valve on 232 bar tank says 34mp. The CIG valve's burst disk doesn't have a stamp.

 

[captain]

There is no pressure rating on the valve itself, use is determined by the burst disc rating.

 

[Aquanaut2000]

Oh my other two tanks have pressures marked on the valves. What's the burst disk to use rating formula?

10.8L CIG with no mark on disk valve
8.0L CIG with 36mp

My other tanks are:
Sea Hornet 12L Steel 232 on tank and 230 on marked on valve.
12.2L Alum 232 on tank and 225 on marked on valve.

 

[rjack321]

Oh my other two tanks have pressures marked on the valves. What's the burst disk to use rating formula?

10.8L CIG with no mark on disk valve
8.0L CIG with 36mp

My other tanks are:
Sea Hornet 12L Steel 232 on tank and 230 on marked on valve.
12.2L Alum 232 on tank and 225 on marked on valve.

burst disks are same as the hydrostatic test pressure. For Al80s that's 5000 psi

The chunk of brass can withstand that just fine but the yoke on the reg and the oring will be very unhappy. Yoke valves are not used >3000psi

 

[Bob DBF]

Yoke valves are not used >3000psi

Scuba yoke valves are not used on 3500#, and over, service tanks because DOT mandates DIN valves.

I use my yoke valve on my Faber MP tank, with a + hydro, that is filled to 3498# on a regular basis, sometimes over 3500#, without issue.

I have an old Sherwood yoke reg from around 1980 made for 4000# service, it was too far ahead of its time and was rendered obsolete since the yoke was cast as part of the first stage and therefore not convertible.

The method of attachment and placement of the o-ring between them is the difference. To seal, both use metal to metat face seal with an o-ring. There are good reasons to choose one over the other, but either one will do quite well, up to 3500# where there is no longer a choice. Of course in the US there are no longer any new 3500#, or greater, steel tanks available.

 

[Boston Breakwater]

I was wondering why our LDSs weren't filling our tanks as much as we wanted and found out that there are many odd tank and valve combos that cross the shop's path. I've got two tank valves that I'm not sure of on my tanks. Can anyone ID them and I'll search up what max pressure (bar) they are rated to?
Many tanks

Hello. What tanks are these fitted on? Also, are the crown markings legible?
There hasn't been a tank made in Australia in about 20 years. Even then, the standards and practices were questionable.

Luxfer did not manufacture scuba cylinder that ruptured in Australia in August 2009

ALERT! Old Aluminum Scuba Cylinders at Risk of Explosion.
Most common cylinders that are made from Aluminum Alloy 6351 are:

1. Luxfer aluminum alloy cylinders manufactured between 1972 and 1988
2. Luxfer aluminum alloy cylinder specification DOT SP6498
3. Luxfer aluminum alloy cylinder specification DOT E6498, E7042, E8107, E8364 and E8422
4. CIG (Australia) aluminum alloy manufactured in or before 1990

https://www.scubaengineer.com/documents/luxfer_qa_south asia technical seminars 2-02.pdf
Personally, I wouldn't use them, or the valves.
Cheers.

 

[halocline]

Yoke valves are not used >3000psi

That's not true, they are used on the SE 3442 PSI tanks frequently. And those are often the convertible valves, which have two o-rings, a yoke and a DIN, on the insert. So theoretically they are more vulnerable than just plain yoke valves that have no machined cavity or threads. Yoke valves are very sturdy with a lot more brass around the air path. It's the yoke fitting on the regulator that would be under stress at high pressures, and some older yokes are not designed for that.

Edit, I see that you also wrote that it's the yoke on the regulator that is the issue, not the valve itself.

 

[rjack321]

That's not true, they are used on the SE 3442 PSI tanks frequently. And those are often the convertible valves, which have two o-rings, a yoke and a DIN, on the insert. So theoretically they are more vulnerable than just plain yoke valves that have no machined cavity or threads. Yoke valves are very sturdy with a lot more brass around the air path. It's the yoke fitting on the regulator that would be under stress at high pressures, and some older yokes are not designed for that.

Edit, I see that you also wrote that it's the yoke on the regulator that is the issue, not the valve itself.

Yeah I meant the yoke part of the regulator. Some can work with higher pressure tanks ok. But these are old yoke valves in AL80s so that's not why the shop is short filling them.

The actual mass of brass in the cylinder neck (aka the valve) doesn't have a pressure rating per se like the OP is asking.