Question about cylinder markings!

[Wookie]

Thats funny!
I buy my O2 from Air Liquid in 50L cylinders at 300 Bar, run a 5 bottle O2 cascade and have been filling my diving cylinders (including 9x 3L 300Bar RB cylinders) to as close to 300Bar as I can get since 1994, without any problems. Hundreds, maybe thousands, of european RB divers have been doing the same for years without burning cities down too. What are we doing that is so different that you are sure that you will kill yourself if you try to do what we do all the time?

Michael

I'm actually stunned. I've filled to 300 bar quite by mistake before, but I've also had cylinder fires boosting over 200 bar more than once, and in the US, PSI recommends not boosting O2 over 200 bar. So I don't. This is something routinely done in Europe? And O2 cylinders from the gas house in the USA come rated for 160 bar or 150 bar. It is rare to see one rated for 180 bar.

I have happily learned something today. I'm still not filling O2 over 200 bar.

 

[michael-fisch]

The tanks in question cannot be rated to have a working pressure of 300Bar since the M26 O2 valve was only specified to 232Bar. That the tank itself works fine at 300 Bar with a minimum specified burst pressure of 1200Bar (when new) is immaterial since the specified working pressure of the valve degrades the Tank/Valve combination to 232Bar.
300Bar G5/8" DIN valves are not stronger than 232Bar G5/8" DIN valves, the different internal shape is to preclude being able to connect a 300Bar fill hose to a 200 (232Bar) tank. Of course, with adapters and modifications, anything is possible.
Michael

 

[michael-fisch]

Having high pressure O2 available, as a matter of course from the gas supplier, reduces our need for boosters.
Running a 5 bottle O2 cascade and returning O2 tanks with 50 Bar remaining in them even if I was using 100 bottles of O2 a year (which I'm not) would not make the purchase of a good booster economically worthwhile.
When I retire to the USA, I'll have to start boosting if I can't find a 4 stage dry and clean small compressor that is designed to pump O2 to ~350Bar.
Not looking foward to having to boost O2 through multiple stages (5>20, 10>40, 20>80, 40>160, 80>320) in order to get HP O2, and building an Ex prepped, fireproof, air conditioned booster room onto the house is also not going to cheap.

Michael

 

[inspirr]

@michael-fisch the research I've done about O2 and cylinder storage pressures was with medical grade cylinders and some welding related stuff and the max value either PSI or BAR was around 230BAR. Then again i bought a O2 clean valve with WP300 so...hmmm? I guess you won't burn down??
Look at the valve picture! The right amount of threads is there, the correct norm is there and at a WP of 300?
And while sitting here full of doubt i just wanted a 300BAR pony bottle))) This SCUBA related cr*p is confusing!

 

[inspirr]

and while at it this is the adapter i'm going to be using:

 

[dcg69]

@dcg69 - almost all tanks are m25x2 neck thread, it's kind of a standard.
the m26 is the thread on which you screw in your regulator! The valve i bought is suitable for the tank and also the o2 factory clean m26 regulator i'm going to use on this tank

You're right , sorry for the confusion

 

[michael-fisch]

Looks like you spent quite a bit of money ar deepstop.de on the adapters. Not cheap, but they work.
Several people I know have had the O2 compatible stainless steel braided hoses go up in smoke. Afterwards a few of them changed over to using the unspecified Bauer UNIMAM fillhoses either in 2 (N2818) or 3 meter (N2819) lengths and haven't had any hose problems since they switched to the Bauer UNIMAM hoses. I've been using the Bauer fill hoses to transfer Ar, He and O2 since 1994 and they work fine - everytime.
Of course if you are using a ball valve to regulate the O2 supply through the hose you deserve everything you're going to get
Got no idea if Bauer USA is using the same supplier for their fillhoses as Bauer Germany does. It would be a good idea to check on that with someone higher up at Bauer in Norfolk, Va before you spend a lot of money on fillhoses.

Michael

 

[inspirr]

@michael-fisch no, the tank, adapter and valve i bought are from a french dealer, not deepstop. No matter the price I won't play with high pressure containers no matter what!
The adapter i was planning on using had 5 threads on it and it seemed fishy to me, 305 kg/cm2 held by only 5 threads??? So i bought this one!
Back to topic:
Is it safe to use this combo for 300BAR nitrox 40 max?

 

[michael-fisch]

The american policy ist that anything up to 40% can be handled as if it is air and does not require special cleaning, the German policy is that anything over 23% has to be handled as if it is pure O2.
I'm pretty sure that nothing you do with 40% is going to cause a fire, although using 40% through a fillhose in order to start a charcoal barbecue did burn a hole in the bottom of my grill through the steel :-(

Michael

 

[happy-diver]

Well you should use a needle valve for boosting the ignition of barbecues