Scubapro DIN conversion kits: 200 vs 300

[jale]

Just to add to the redondant info that the thermo valve has a small hole and sometimes some reg with 200b fitting have problems to get a proper seal resulting of a small leak at this hole.
Never a problem with a 300b fitting as you can "force" a bit more the screw (yes i know that the leak means improper seal and that a change of o-ring is needed but ...reality practical check )

 

[marcin.a]

I was diving 300 bar cylinders in Norway for many years. And yes, I was pumping those cylinders up to 300 bars. Among fellow divers it was roughly 50/50 split between 200 and 300 bar. Twinsets were usually 200, singles 300. But all rental cylinders I have seen in Norway and a few other European locations were always DIN 200 bar. I have never seen a 300 bar DIN valve on 200 bar cylinder. I think it was actually illegal. But e.g. in Australia you can put 300 bar valve on 200 bar cylinder. I have not seen a 300 bar cylinder in Australia. Rental standard here is 200 bar yoke.

 

[koen4162]

I have just purchased the DIN conversion kit for my "almost vintage" Scubapro MK15 1st stage, originally equipped with a 3000 PSI Yoke.
This is the Ebay auction I won, for SP part no. 10.045.020:
KIT DIN SCUBAPRO 200BAR 10.045.020 | eBay
View attachment 555506

Now, I see that SP also manufactured a very similar kit, part no. 10.045.030, featuring the "300 bar" version of the DIN connection, which is identical but has a longer threaded part.
SCUBAPRO conversion kit, Univ., INT/DIN 300 Bar - 10.045.030 | eBay

My 15-liters Cressi tank, almost 30 years old, is equipped with an H-valve featuring two DIN 200 bar valves, so the kit I bought will definitely work with it.
But I am wondering if, when travelling and getting tanks from local dive centres, there is the risk that the available tanks are equipped with 300-bars DIN valves...
What I see around are usually valves which can accept both yoke and DIN regs, and with a screw-in plug which must be removed, using an hex key, for mounting a DIN reg.
Something similar to this one:
View attachment 555507
I am supposing that all these dual-purpose valves are 200 bar.
Is this true?
Are you aware of places where 300-bar DIN valves are in use, and hence I need a 300-bar DIN regulator for using them?

A DIN 1st stage has a O ring at the end which buts to the valve on the cylinder to seal.
The longer DIN 300 bar 1st stage may seal both DIN 200 bar valves (on a 200 or 230 bar rated cylinder) and DIN 300 bar valves (on a 300 bar rated cylinder)
The shorter DIN 200 bar 1st stage may only seal a DIN 200 bar valve, because it does not but to the DIN 300 bar valve. That is an engineered safety feature.

A lot of divers in W Europe use their own 300 bar composite 12 l tanks (12 l * 300 bar= 3 600 bar l of air) which have slightly more air and weigh 3 to 4 kg less than a steel 15 l 200 bar tank (15 l * 200 bar = 3 000 bar l of air).
Dive shops prefer the cheaper and less fragile aluminium 12 l 200 / 230 bar tanks, which limit compression dives because of the smaller amount of air .

 

[Storker]

I was diving 300 bar cylinders in Norway for many years. And yes, I was pumping those cylinders up to 300 bars.

Of course. Why shouldn't you?

Among fellow divers it was roughly 50/50 split between 200 and 300 bar.

Very few 200 bar tanks seen today. 232 is perhaps the most common, but there's a significant number of 300 bar tanks as well.

 

[Storker]

A lot of divers in W Europe use their own 300 bar composite 12 l tanks

Huh. I've never seen one.

What's the point? Every kg you save on the tank has to be added to your belt, weight pockets or plate. As long as the total weight of the rig allows for some ditchable weight, there's really no point in shaving weight from the tank.

 

[kelemvor]

???
3500 PSI is 240 bars, not 300. Which valve is mounted on that cylinder?
The Scubapro DIN conversion kits are inexpensive. So if it gives advantages I can easily swap my one with a 300 bar one. But I still do not see the point, as it appears that these 300-bars valves are very rare...
And a 300-bar converter is longer, meaning that the regulator will protrude more towards my head, and it will fix to the 200-bar valve with only part of the threads, which appears slightly less safe to me.

OK I worded that poorly. It's a 3500psi tank that has a 300 bar valve as the 200 bar valve would be insufficient.

 

[Storker]

OK I worded that poorly. It's a 3500psi tank that has a 300 bar valve as the 200 bar valve would be insufficient.

3500 psi = 241 bar. A "200 bar" valve is in reality a 200/232 bar valve. According to regulations, a 200/232 bar valve may well insufficient for a 3500 psi tank, but the difference is so marginal that you'd probably do fine. 232 bar = 3365 psi. That's a 4% difference. At least I am quite fine with a 10% hot overfill.

 

[kelemvor]

3500 psi = 241 bar. A "200 bar" valve is in reality a 200/232 bar valve. According to regulations, a 200/232 bar valve may well insufficient for a 3500 psi tank, but the difference is so marginal that you'd probably do fine. 232 bar = 3365 psi. That's a 4% difference. At least I am quite fine with a 10% hot overfill.

I didn't install the 300 bar valve. The tank came with it. I have kind of kicked around the idea of replacing it. After all I pump my lp steels up over 3500 and they have 200 bar convertible valves.

 

[Bob DBF]

OK I worded that poorly. It's a 3500psi tank that has a 300 bar valve as the 200 bar valve would be insufficient.

The difference between using a 200 bar and 300 bar fitting is a matter of DOT regulation, not the ability of the valve to withstand pressure. It is more a function of the burst disc, what pressure a valve will withstand. The convention of 200 bar was started because the high pressure tank of the day was 3000#. When the tank pressure went up the same valve, with a higher pressure burst disk was sometimes called 232 bar, and now could be called a 241 bar, but 200 bar stuck as a differentiation from other than 300 bar.

The main point is that valves, even old valves, are designed to withstand well over the service pressure so the burst disc relieves before the tank, or valve, fails.

I have a Sherwood yoke reg from the early '80's that was made for 4000# service using the yoke valves of the time. I guess they were looking foward to higher tank pressures, but didn't foresee the change to DIN for the higher pressure tanks. It also points out that the yoke configuration is not as pressure limited as some would say.


Bob

 

[Storker]

The difference between using a 200 bar and 300 bar fitting [...]

I may perhaps have mentioned this once (or twice, or thrice) before, but it isn't 200 bar. Its 200/232 bar. That's a >30% difference.