Scubapro DIN conversion kits: 200 vs 300

[Zef]

My 10x300s hold pretty exactly as much gas as the 12x232s I see all the time around here. 10*300=3000 and 12*232=2784, but rule of thumb is that a 300 bar tank holds about 10% less gas than nominal capacity.


Can't say I've ever seen a D8x300 set. D7x300 and D8.5x232, though, are rather popular around here.

Lets just say that Belgium is the land of the unique. I see stuff here all the time that I have not seen elsewhere.

The whole gas compressibility issue is why I wrote "roughly" in my earlier post.

-Z

 

[Mod63]

D8x300 has been the tank of choice when D8,5x300 has been hard to come by in Germany.

 

[Angelo Farina]

A 300 bar valve is deeper than a 200 bar valve and while the threaded insert will screw in it will go in too far and yolk 1st stage will not be able to make a proper seal..if the insert is not screwed in all the way the back of the insert will not seal to the back of the valve...this prevents one from attaching a 200/232 bar 1st stage on the HP tank/valve and causing damage to the 1st stage

Great!. This solves all my doubts.
As currently my SP MK15 is in its original configuration, which is rated at 3000 PSI, it is correct to fit it with a 200bar DIN adaptor, for avoiding the risk that it is mounted on a 300bar cylinder. The seat cannot withstand such an high pressure.
When I will manage to find and install the SP MK15 upgrade kit, which can make it withstand much higher pressure, then I can mount a 300bar DIN adaptor on it.
It would be unsafe to use a 300DIN adaptor on my reg, as it is currently not rated to operate at such high pressure.

 

[halocline]

It would be unsafe to use a 300DIN adaptor on my reg, as it is currently not rated to operate at such high pressure.

That's not true at all. Installing the 300bar DIN fitting places no more stress on your reg as the 200bar, they are identical from the reg's point of view. What might be considered unsafe iin terms of the "rating" is using your reg with a 3500 PSI tank, but that has nothing to do with the DIN, it has to do with the older seat and retainer. I honestly don't know. Since the pressure on the seat from the piston edge is determined by IP, the only way using HP tanks would increase that would be if the IP also went up.

The 300bar DIN fittings are like 20 times as common as the 200bar fittings. I've only seen one SP 200bar fitting in my life. You mentioned in a previous post that you thought using a 300 bar fitting might be less safe in a 200 bar valve because there are a few threads sticking out, but keep in mind that the same number of threads are engaging with the valve with either DIN fitting, it's just that the 300 bar fitting has 2 extra threads. In the U.S., practically everyone who uses DIN uses a 300bar fitting, and usually you only see 300 bar valves on older twin manifolds, at least that's where I see them.

My MK15s have the older metal ring DIN fittings, and they're 300bar. I'm sure that SP sold original MK15s with the 300 bar fittings before they converted the HP seat/retainer.

 

[Angelo Farina]

The 300bar DIN fittings are like 20 times as common as the 200bar fittings. I've only seen one SP 200bar fitting in my life.

This was my original question. On this side of the Atlantic, instead, ALL valves are DIN-convertible (with the insert), so they can also be used with yoke; including twin manifolds. I have never seen a true 300-bar DIN valve here, and for this I was asking if they are in use somewhere...
Now I see that in US they are actually in use! Thanks for clarifying this...

You mentioned in a previous post that you thought using a 300 bar fitting might be less safe in a 200 bar valve because there are a few threads sticking out, but keep in mind that the same number of threads are engaging with the valve with either DIN fitting, it's just that the 300 bar fitting has 2 extra threads.

That's not entirely correct. If you place the 200bar and 300bar adaptors side by side, you will see that in the 300 bar one the end part, carrying the O-ring, is approximately 2mm longer, so the threaded part starts at greater distance form the O-ring.

200bar left, 300bar right

When fitting a 200bar DIN valve, a 300bar adaptor will screw on for 2 complete turns, instead a 200bar one screws for 5 complete turns.
According to DIN standard this is accepted and is still fully safe. But it is not "equally safe", it simply means that, being the pressure just 200 bar, those 2 turns threads are enough. But of course 5 turns is better!

 

[Storker]

On this side of the Atlantic, instead, ALL valves are DIN-convertible (with the insert), so they can also be used with yoke;

I'm not clear on what you're trying to say here. ALL valves east of the Atlantic can take an insert and be yoke compatible? No. Only 200/232 bar valves can do that, 300 bar valves can't.

I have never seen a true 300-bar DIN valve here,

Well, as more than one poster has pointed out upthread, 300 bar tanks - and thus 300 bar valves - are not uncommon in Northern Europe. So I guess that the reason that you've never seen a 300 bar valve is because 300 bar tanks are uncommon in your neck of the woods. Not in Europe, but in your specific part of Europe.

Me, I've never seen a 200/232 bar DIN 1st stage; they've all been 300 bar. Come to think about it, the only yoke/A-clamp regs I've seen have been old, obsolete and long time out of service.

Those around here who use 232 bar tanks - probably a slight majority of rec divers and more or less every tech diver - have no issues with those two threads sticking out from their tank valve. In fact, you're the first person I've heard worrying about that being a potential problem.

EDIT: I've linked to this excellent article about DIN fittings a few times before. Perhaps it's time to mention it again.

 

[Storker]

200bar left, 300bar

Those are fill whip valves, designed to make it impossible to fit a 300 bar fill whip to a 200 or 232 bar tank.

This is an actual 300 bar 1st stage (Apeks, in case anyone were wondering):

 

[Angelo Farina]

I'm not clear on what you're trying to say here. ALL valves east of the Atlantic can take an insert and be yoke compatible? No. Only 200/232 bar valves can do that, 300 bar valves can't.

Exactly. This means that here (or at Maldives, or in Red Sea, etc.) I have only seen DIN200 valves.

Well, as more than one poster has pointed out upthread, 300 bar tanks - and thus 300 bar valves - are not uncommon in Northern Europe. So I guess that the reason that you've never seen a 300 bar valve is because 300 bar tanks are uncommon in your neck of the woods. Not in Europe, but in your specific part of Europe.

Possible. But who ever wants to go diving, say, in Norway ??? Diving Europe, for me, means Mediterranean sea: Spain, France, Italy, Croatia, Greece. Very nice places, in many cases better than any tropical site.
Then there are tropical sites such as Maldives, Red Sea, Thailand and Caribbean.
So the question is the same as at beginning: in places where it is worth diving (not oil platforms in the North Sea), Is there any chance that rented cylinders are only fitted with a DIN-only 300 bar valve, despite being filled at 232 bars?
If there is this possibility, then I will replace the 200-bar DIN adaptor with a 300-bar one. If this is substantially impossible, as it appears to me, I think that keeping my current 200-bar DIN adaptor will not limit the usage of the regulator, and is safer, as it will impede to mount it on a cylinder filled at 300 bar (for which it is not rated), and provides better mechanical coupling with a 200-bar valve.
I am not suggesting that using a 300-bar adaptor would be unsafe, simply that there is no reason for swap it with the 200-bar one, as there will be no advantage and small additional risks.

 

[Eksilbergenseren]

Possible. But who ever wants to go diving, say, in Norway ???

I do not know if you are ignorant or just trolling, but comparred to the medetereanian, diving the west coast of norway is fantastic. Unfortunately I have no dive equipment with me on christmas holliday, but looking out at crystal clear water with kelp forrest and lots of fish, I would not hesitate to jump in, even if the temperature is just above freezing. A 10 or 12 liter 300 bar would be perfect in combination eith a buoyant dry site.

 

[Angelo Farina]

I do not know if you are ignorant or just trolling, but comparred to the medetereanian, diving the west coast of norway is fantastic. Unfortunately I have no dive equipment with me on christmas holliday, but looking out at crystal clear water with kelp forrest and lots of fish, I would not hesitate to jump in, even if the temperature is just above freezing. A 10 or 12 liter 300 bar would be perfect in combination eith a buoyant dry site.

Sorry, I am just ignorant, and I do not like too much cold water...