Question - 200 vs 300 Bar isolators etc

[texdiveguy]

I use DR and Thermo 200 bar units, work great.

 

[Goindrinkn]

Thank you for all the helpful information... and for the the gentleman who felt it necessary for the somewhat condescending remark, thanks for your input as well. If I am misreading the condesending nature, I apologize, it's the monday after a holiday and I'm back at work... however as far as doing me research:

I am doing my research. That's why I asked the question in the first place... I have looked, and see plenty of information that caused me to think that there's a difference in pressures, such as:


*****

232 bar DIN (5-thread, G5/8) - the regulator screws into the pillar valve trapping the O-ring securely. These are more reliable than A-clamps because the o-ring is well protected, but many countries do not use DIN fittings widely on compressors, or cylinders which have DIN fittings, so a European diver with a DIN system abroad in many places will need to take an adaptor.

A yoke (A-clamp) to DIN adaptor300 bar DIN : (7-thread, G5/8) - these are similar to 5-thread DIN fitting but are rated to 300 bar working pressures. The 300 bar pressures are common in European diving and in US cave diving, but their acceptance in U.S. sport diving has been hampered by the fact that United States Department of Transportation rules presently prohibit the transport of metal scuba cylinders on public roads with pressures above about 230 bar, even if the cylinders and air delivery systems have been rated for these pressures by the American agencies which oversee cylinder testing and equipment compatibility for SCUBA (OSHA and CGA). Note that reference to M25 threads refers to the tank neck thread not the valve size.

******


And the fact that many of the manifolds for purchase on different sites, use a spec of 3000 lbs for a working pressure for the 200 bar / but mention a max pressure of 4500 on the ads for similar 300 bar product. Why don't they mention a max pressure for the 200 bar? wouldn't one assume it's something other than 4500 psi?


Now I'm not arguing the validity of the statements above, I am merely pointing out that there is information that could lead one to believe otherwise... And again, that is why the question was asked ... to find out ... and specifically in the tech diving forum as my guess was that these would be the people with highest level of practical use, to give a simple and concise answer that I could understand.

So again to them I say thanks.

 

[Bismark]

Thank you for all the helpful information... and for the the gentleman who felt it necessary for the somewhat condescending remark, thanks for your input as well. If I am misreading the condesending nature, I apologize, it's the monday after a holiday and I'm back at work... however as far as doing me research:

I am doing my research. That's why I asked the question in the first place... I have looked, and see plenty of information that caused me to think that there's a difference in pressures, such as:


*****

232 bar DIN (5-thread, G5/8) - the regulator screws into the pillar valve trapping the O-ring securely. These are more reliable than A-clamps because the o-ring is well protected, but many countries do not use DIN fittings widely on compressors, or cylinders which have DIN fittings, so a European diver with a DIN system abroad in many places will need to take an adaptor.

A yoke (A-clamp) to DIN adaptor300 bar DIN : (7-thread, G5/8) - these are similar to 5-thread DIN fitting but are rated to 300 bar working pressures. The 300 bar pressures are common in European diving and in US cave diving, but their acceptance in U.S. sport diving has been hampered by the fact that United States Department of Transportation rules presently prohibit the transport of metal scuba cylinders on public roads with pressures above about 230 bar, even if the cylinders and air delivery systems have been rated for these pressures by the American agencies which oversee cylinder testing and equipment compatibility for SCUBA (OSHA and CGA). Note that reference to M25 threads refers to the tank neck thread not the valve size.

******


And the fact that many of the manifolds for purchase on different sites, use a spec of 3000 lbs for a working pressure for the 200 bar / but mention a max pressure of 4500 on the ads for similar 300 bar product. Why don't they mention a max pressure for the 200 bar? wouldn't one assume it's something other than 4500 psi?


Now I'm not arguing the validity of the statements above, I am merely pointing out that there is information that could lead one to believe otherwise... And again, that is why the question was asked ... to find out ... and specifically in the tech diving forum as my guess was that these would be the people with highest level of practical use, to give a simple and concise answer that I could understand.

So again to them I say thanks.

As you may have noticed, this forum is not the warm and fuzzy place that other forums are......must have something to do with the personality types that tend to pursue this kind of diving, right Jeff?

 

[JeffG]

must have something to do with the personality types that tend to pursue this kind of diving, right Jeff?

and just what are you implying? Huh!

 

[divestoclimb]

There's a lot of misinformation out there, but the Dive Rite Express article linked above has it right.

The problem stems from a practice in the compressed gas industry to use different fittings for every type of gas (air, EAN, O2, CO2, He, ...) so incompatible cylinders and regulators cannot possibly be interchanged. This kind of setup works well in a commercial setting where your work force might make a mistake and where there's enough money (and usually a business need anyway) to buy one of everything, but in recreational SCUBA it's unnecessary. All it does is make people believe there's some reason why fitting A is better than fitting B, but in fact the two are different for no reason other than to stop some wage laborer from blowing something up.

The best bet for a diver is to use the fittings that guarantee maximum interchangeability between all the various fittings out there which currently means 300 bar DIN regulators and 200 bar DIN tank valves. Both of these can be mated with yoke, 200 bar DIN and 300 bar DIN with the right insert or adapter. If you do go with 200 bar valves on high pressure cylinders, that's fine as long as you never hook up a 200 bar regulator while the cylinder is pressurized above the pressure rating on the regulator, and never use a normal yoke regulator or adapter when the cylinder is pressurized above 230 bar (about 3400 psi). There's nothing wrong with using an underfilled cylinder in those cases.