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

[Kat88]

I've read some stuff from dive rite about the "Difference between DIN 200 Bar and 300 Bar" and it says at one point:

Is a 300 BAR SCUBA valve outlet stronger than 200 BAR?
No, they are the same. Only the first few threads in both the 200 BAR and 300 BAR outlet designs are doing the work, the remaining threads on the 300 BAR outlet are there simply to create a deliberate incompatibility with a 200 BAR connector. In fact, in practice, the 300 BAR valve outlet has proven itself to be more fragile than the 200 BAR valve outlet. The 300 BAR valve outlet is so long that the smallest 'ding' on the edge of the opening can slightly warp the cylindrical opening, causing the regulator to become difficult or impossible to completely seat. This problem does not seem nearly as pronounced with the 200 BAR valve outlets; although it remains an issue and all DIN outlets should be protected from dings.


But I'm still not sure, and want to double check.

I've just obtained two 300 Bar 7 L steel tanks, but one of my regs is yoke and the other is DIN. The tanks have got a 300 bar DIN valve each, and I've got a spare 232 bar valve, DIN with the yoke insert.

Will the 232 bar valve survive on my 300 bar tank? (until I convert that pesky first stage to DIN)

 

[knowone]

Mine do, if the valve to tank threads are the same.



SCUBA Valves: Regulator Fittings, 200 vs 300 Bar FAQ and Cylinder Neck Threads - Dive Gear Express

 

[naick]

This is a VERY dangerous idea. It is dangerous to you and the people arround you.
A yoke regulator can absolutely not be used for 300 Bar, yokes are only rated to 200bar. This connection is not appropriate. Just chuck out 50 dollars and convert your reg to DIN 300 bar.

 

[thanksforallthefish]

This is a VERY dangerous idea. It is dangerous to you and the people arround you.
A yoke regulator can absolutely not be used for 300 Bar, yokes are only rated to 200bar. This connection is not appropriate. Just chuck out 50 dollars and convert your reg to DIN 300 bar.

If you have a 300bar tank and a 200 bar valve i would imagine that you would only get a 200bar fill, you would in Australia, so i cant see a problem as long as the fill pressure is only to the lowest WP of tank or valve

 

[Texfrazer]

This is a VERY dangerous idea. It is dangerous to you and the people arround you.
A yoke regulator can absolutely not be used for 300 Bar, yokes are only rated to 200bar. This connection is not appropriate. Just chuck out 50 dollars and convert your reg to DIN 300 bar.

Since I'm from the states, I'm going to convert to psi, so.....

A 300 bar valve is thusly rated to 4351 psi, while a 200 bar valve (which is actually a 232 bar) is rated to 3364.9 psi.

To my knowledge, the highest pressure scuba cylinders (at least in the US) are only rated at 3500 psi (241.3 bar), with the majority of high pressure cylinders rated at 3442 psi (237 bar).

In fact, the 3442 cylinders have neck sizes that will accept the 200 bar valves (and most come with them from the factory).

Some of the first yoke regulators to be rated to 3000 psi (207 bar) were the scubapro Mk5's with the weird barn shaped yoke. I would not use these on routinely on even standard 300 psi Al 80's. The later, more beefy yokes, are another story. These are certainly capable of being used on much higher pressures, and if you're ever in "cave country" you'll see these in use on tanks with 3400 - 3600 psi (234 - 248 bar) routinely.

Therefore, I would not hesitate to use a modern yoke regulator on a 232 bar valve in a 3442 psi (237 bar) tank. But that's just my opinion.

 

[Scared Silly]

A 300 bar valve is thusly rated to 4351 psi, while a 200 bar valve (which is actually a 232 bar) is rated to 3364.9 psi.

The above is hog wash. The bar rating on a valve has nothing to do with with the rated pressure that the valve can be used at. The only difference is two threads.

My question to the OP is what is the service pressure of the cylinder? That is what is going to dictate everything. If the cylinders are truly 300bar then as said most yoke fittings are not made for 300 bar - there made be some though. The other question is can your get them filled to their rated pressure? If not, then putting the 200 bar valve on for now would be okay if the fills are in line with your reg, i.e. 232bar.

At this point I would just convert the reg to DIN and have no worries. The conversion will not cost that much in the big scheme of thing. Then save your yoke fitting for when traveling to warmer waters. Conversely, you can take some of the parts from the yoke and make a DIN-to-Yoke adapter.

 

[Diver0001]

That idea has bad mojo.

A scuba tank with 200 bar in it (let alone 300) is a bomb waiting to go off. That's what I tell my OW students and I think most people would agree.

If you start mix-and-matching different threads it's a bad idea and even *IF* you manage to get the valve onto the tank then you're creating a loaded gun that's going to be in your car, laying on the floor in your house where your kids are playing and pointed straight at the back of your head when you're diving.

If the threads don't match then the question isn't really *IF* it will fail. The question is how bad will it be. A few years ago a diver here dropped a twin-10 on the ground by accident (it rolled out of his car) and something broke. It blew 100m away from where it fell and the shrapnel shattered one of his arms. And that was on a tank where the valves *fit*.

Your second question is really, "can I put a 200bar INT regulator on a 300bar tank if I can somehow make it fit". The answer to this is categorically, "NO". The regulator can take the pressure, there is no difference between the regulators for 200 and 300 bar use besides the DIN coupling. The problem is that the extra pressure will almost certainly lead to the O-ring extruding from the coupling on a regular basis. Although I've never tried it I will predict right now that you'll have nothing but trouble with blown O-rings and free-flows happening at random intervals after turning on the tank. You don't need this, and you don't want this.

The alternative is to do what should be done. Put a proper valve on it and get your reg converted to DIN (which can normally be done for about $50). Sometimes a small investment can avoid big problems.

R..

 

[Jimmer]

I think you're mis-understanding. Its not the tank neck threads that are the concern, its the valve to regulator threads. The valve will fit the tank just fine and hold 300 bar no problem, its the use on a yoke reg that is the concern.

That idea has bad mojo.

A scuba tank with 200 bar in it (let alone 300) is a bomb waiting to go off. That's what I tell my OW students and I think most people would agree.

If you start mix-and-matching different threads it's a bad idea and even *IF* you manage to get the valve onto the tank then you're creating a loaded gun that's going to be in your car, laying on the floor in your house where your kids are playing and pointed straight at the back of your head when you're diving.

If the threads don't match then the question isn't really *IF* it will fail. The question is how bad will it be. A few years ago a diver here dropped a twin-10 on the ground by accident (it rolled out of his car) and something broke. It blew 100m away from where it fell and the shrapnel shattered one of his arms. And that was on a tank where the valves *fit*.

Your second question is really, "can I put a 200bar INT regulator on a 300bar tank if I can somehow make it fit". The answer to this is categorically, "NO". The regulator can take the pressure, there is no difference between the regulators for 200 and 300 bar use besides the DIN coupling. The problem is that the extra pressure will almost certainly lead to the O-ring extruding from the coupling on a regular basis. Although I've never tried it I will predict right now that you'll have nothing but trouble with blown O-rings and free-flows happening at random intervals after turning on the tank. You don't need this, and you don't want this.

The alternative is to do what should be done. Put a proper valve on it and get your reg converted to DIN (which can normally be done for about $50). Sometimes a small investment can avoid big problems.

R..

 

[Diver0001]

I think you're mis-understanding. Its not the tank neck threads that are the concern, its the valve to regulator threads.

I see....

In Europe the tank-neck-threads are different too if I'm not mistaken, which lead to this assumption.

The valve will fit the tank just fine and hold 300 bar no problem, its the use on a yoke reg that is the concern.

It still won't work. I give it an 75% chance of the o-ring being forced to extrude every time you turn it on. It might work once but it won't work every time.... I would put money on that.

R..

 

[Jimmer]

I see....

In Europe the tank-neck-threads are different too if I'm not mistaken, which lead to this assumption.



It still won't work. I give it an 75% chance of the o-ring being forced to extrude every time you turn it on. It might work once but it won't work every time.... I would put money on that.

R..

I absolutely and 100% stand by my statement that it will fit, and hold 300 bar. But yes I agree that using a yoke with 300 bar is not a good idea, and not just because of the o-ring extrusion, but because most yokes aren't built for that pressure.

O.P. go ahead and use it, but keep the fill pressure to whatever the yoke is rated for, probably 232 bar.