is a 300 bar tank with a 232 bar valve ok?

[naick]

Well... in Europe I"m pretty sure that a 200 valve won't even screw into the neck of a 300 bar tank. There are good reasons for this. They've even gone so far (thankfully it isn't a law yet) that nitrox regs won't fit on a valves for "air" tanks.

The standards in other places seem to be quite different so I apologise if I got my panties in a bunch for nothing. I assumed that the op wanted to essentially "cross thread" a 200 bar valve into a 300bar tank.

As for DIN, it would appear that that 200 and 300 bar standards are pretty universal.

Regarding Jimmer's assessment (which is better informed than mine, i'm sure), that the proposed stop gap measure would work, I"m sure he's right provided the valve will screw normally into a 300 bar tank and you don't pump it up to it's maximum operating pressure.

R..

All scuba tanks have the same thread in the tank here: M25. So you could use a 200bar valve on a 300 bar tank. But the 300 bar filling whips have this nipple thing on the end, so it doesn't seal on a 200 bar valve. You could put a 300 bar valve on a 200 bar tank. But I've never heard about this or any accidents happening because of it.

As for the nitrox regs, yes there is different fitting for this. But this is for use with >40% oxygen only. But I don't know anyone that has one of these. They aren't used arround here. It's a very silly thing. Dive shops just fill your deco bottles aswell even if it has the normal DIN fitting. I haven't heard of any country in Europe where they make a hassle about it. It's just a guideline the EU has made, so like you said, it's not a law. The reg manufacturers have jumped on the wagon though and only sell nitrox regs with the new M26 fitting. Most LDS's just switch it to a normal 300 bar fitting for free.

 

[Diver0001]

Thanks for the clarification!

R..

 

[Gilldiver]

Some background on Yokes in the US, the yokes made in the 50’s and the 60’s were designed for 2250 PSI (150 BAR) tanks and can/have been used for tanks at 3000 psi but the yokes may stretch and let the o-ring extrude, some have cracked.

When the 3000 PSI (200 BAR) aluminum tanks came out the yokes were beefed up and are stamped 3000 PSI. My Poseidon regs have DIN to Yoke converters stamped 200 BAR, so again 3000 PSI service.

I looked at my Conshelfs an early Conshelf XI (1972) has a Yoke clipped on with a C-clip and a later one (1974) has a screw on yoke, both are rated for 3000 PSI service. Now a Conshelf SE2 I have from the mid 80’s has the same screw on yoke stamped for 4000 PSI (266 BAR) service. As the highest tank in normal service in the US is 3500 PSI (233 BAR) this yoke can be used on all tanks.

So, after about 1970, it looks like the rating of Yokes is more a function of what tank pressures were available at the time and not the design of the yoke itself.

 

[knowone]

Even the skinny yokes all over the world from the 60s are rated 200 bar.
at least

All heavy yokes from all over the world after that are rated at 300 bar.
at least

All valves are made from the same lump of brass.
it must be big

Where do the Europeans keep their burst disc?
is it in the tank

Nothing extrudes from anywhere unless that anywhere is deformed.
a user issue.

Stamps on yokes and valves regarding pressure mean nothing.

The weakest link is the connection into the first stage.

Why doesn't the bourdon tube explode.

DIN is just more over engineered fallible malarkey.

Everything is a user issue to beware.

 

[coinking]

After this this discussion I'm not completely clear on the right answer to my question. My brand new Titan LX Supreme (yoke) is stamped "232 bar max - 3300 psi". I'm considering purchasing a high pressure steel cylinder (3442 psi working pressure). Would I
still be able to use my regulator on a HP steel cylinder filled to its 3442 psi
working pressure with the existing yoke? Would converting my reg to 300 DIN eliminate the issue?

 

[Leadking]

After this this discussion I'm not completely clear on the right answer to my question. My brand new Titan LX Supreme (yoke) is stamped "232 bar max - 3300 psi". I'm considering purchasing a high pressure steel cylinder (3442 psi working pressure). Would I
still be able to use my regulator on a HP steel cylinder filled to its 3442 psi
working pressure with the existing yoke? Would converting my reg to 300 DIN eliminate the issue?

The simple answer is "Yes" 3442psi is a U.S. temperature compensated equivalent to the European standard. I posted this on the Board years ago. Converting your regulator will also eliminate the issue.

 

[Leadking]

The simple answer is "yes" . While the manufactures can stamp various ratings on their yokes the CGA and ISO actually set the standards. DOT says to use the CGA standard or any other "RECOGNIZED STANDARDS" for outlet configurations. CGA does not recognize the Yoke configuration above 3000 psi, ISO recognizes it to 230 bar @15C/which has been temperature corrected to 3442 psi@70F for the US.

 

[oxyhacker]

The pressures marked on yokes seem to be chosen almost at random. Many manufacturers used to mark them 3000 psi probably because that's what the CGA rated the yoke interface as good for, and some 3300 because at one time 3300 was the highest yoke-valved tanks one could buy. Others put higher pressures on them either because that's what the yoke (if not the O-ring) could really handle, or because they figured the higher the number the better potential buyers would assume the reg must be - I've seen them marked 4000 psi, and there are rumors of 5000 psi ones.

This produced some odd results. At one point Scubapro was marking all their yokes 3000 psi, but selling yoke-valved 3300 psi tanks. Did they not expect buyers to use their regs with their tanks? And Aqualung not too long ago was selling yokes marked 3000 psi on one side and 230 bar on the other.

I think the latter came about because the CGA rated the yoke interface as good for 3000 psi, but European standards rated it for 230 (or 232, or 234 depending on what nation's or organisation's standards you were going by) so AL was trying to label them by what was permitted on both sides of the pond.

Eventually, as it was explained to me, someone noticed that the CGA also permitted going by other recognized standards, so US vendors started using the 230 bar european standard, which as leadking explains (and not for the first time, he is a patient man) can with a bit of finagling be made to come out as 3442.