200 Bar valve versus 300 Bar

[seafloor]

Hello,

I have converted my reg to DIN and was wondering is there any advantage to using the 200 bar valve (w/ yoke insert) versus the 300 bar valve. I have read about the 5 thread versus the 7 threads on each one. I'm just wondering how many folks actually use a 300 bar valve. My tanks came with the Pro Outlet -- 200-Bar DIN / Yoke (K), but I was debating if I should have purchased the 300 bar valves instead. I won't be using the yoke insert and if I need to dive while traveling I could purchase the DIN to yoke adapter


~Thanks for your thoughts

 

[thmoose51]

Go to Dive Rite Express and you can find information about the difference.

 

[ianr33]

The 300 bar valve will,in theory, be a little stronger. In practice both will be more than adequate.

Only downside to a 300 bar valve is that there is no way to ever use a Yoke reg on it.

 

[Greg Barlow]

The 300 bar valve will,in theory, be a little stronger. In practice both will be more than adequate.

Only downside to a 300 bar valve is that there is no way to ever use a Yoke reg on it.

This is actually incorrect. Only the first few threads of a threaded fitting take on the mechanical load of pressurization. Given the tolerances allowed in DIN threads, I doubt if more than the first 3 threads on either fitting have any significant load on them.

Me, I use 300 bar reg fittings, and 200 bar female fittings on cylinders with service pressures from 182-235 bar. Then again, if you are using true 300 bar cylinders, you should be using the 300 bar valves to prevent anyone from attaching a yoke fitting to the assembly. I dare say that a yoke rated for 200-235 bar would likely be structurally weakened by 300 bar pressures. I sure wouldn't want that regulator first stage pointing at the back of my head and/or neck.

The 300 bar fitting was engineered to prevent someone from accidently attaching a fitting that was not designed for such pressures. It is too deep to allow a yoked reg or 200 bar male fitting to make a sealed connection.

Greg Barlow

 

[ianr33]

I was thinking more along the lines of how strong a 300 bar valve is if you whack it on the ceiling of a cave. Presumably it is a bit more resistant to deforming? Any thoughts on that? (Other than you should not be hitting anything in the first place !!)

 

[texdiveguy]

You mean there are several different types....

 

[spectrum]

The only reason to use the 300 BAR valve is to satisfy the standard for a 3500+ PSI cylinder.

The 200 BAR pro valve will give you the most flexibility when going to a yoke only fill station. You are better off screwing your clean bushings in than letting them use their beat up brass block. It also lets me rig all of my cylinders for immediate, simultaneous fills when they com through the door. I would have no concerns about 5 threads being enough to hold it all together. If anything is the weak link it's the swivel stem of your DIN connector.

Speaking of the brass block DIN fill adapter. Many shops remove the pilot that is supposed to prevent it's use in a 200 BAR valve so that system is already broken.

Depending how much you plan to travel, how DIY you are and your specific regulator you may be better of getting the companion yoke assembly and swapping the DIN unit out for travel. The converting adapter can get gaumy in some configurations.

Pete

 

[Rick Inman]

Speaking of the brass block DIN fill adapter. Many shops remove the pilot that is supposed to prevent it's use in a 200 BAR valve so that system is already broken.

Depending how much you plan to travel, how DIY you are and your specific regulator you may be better of getting the companion yoke assembly and swapping the DIN unit out for travel. The converting adapter can get gaumy in some configurations.

Pete

Thanks, Pete. You just never know what you'll learn reading a SB thread.

I didn't know the thing on the brass din adapter was called a "pilot". And now I know a new word: Gaumy!

 

[Luis H]

I was thinking more along the lines of how strong a 300 bar valve is if you whack it on the ceiling of a cave. Presumably it is a bit more resistant to deforming? Any thoughts on that? (Other than you should not be hitting anything in the first place !!)

The deeper 300 BAR female valve is actually more susceptible to deformation and damaged. A short stubby cylinder is stronger that a long one.

Read this link from Dive Rite:
Valves, Regulator Fittings, Cylinder Neck Openings -- More than you wanted to know


Quote from Dive Rite:

"Is a 300 bar SCUBA valve outlet stronger than 200 bar? No, they are equally strong. 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."


I have been using DIN fittings for over 35 years and I can't recall when the 300 BAR fitting first came out. IMHO it is a bad idea. Just trying to make the system "idiot proof" is pointless. Idiots will always be very clever when they want to screw up something.



Oh, and for long term durability, the yoke fitting will outlast a DIN after many years of use. In the long run the threads do get a lot of wear.

 

[Scared Silly]

I have several 300 bar manifolds - all of them have SS plugs for the exact reason Luis states.

Also as Pete says having Yoke assembly is nice - we sold two of our 4 DIN-to-Yoke converters and got Yoke assemblies. Saves on the gaumy and noob factor - as many DM have not seen a DIN assembly so they are not sure what to do when the yoke is not attached.

Luis, the 200 vs 300 is dumb but the air vs Nitrox threads is even dumber.