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Hi world

I have a question that I am sure someone out there can answer for me.

We have all been told to use special "O" rings when using O2 in mixes greater
than 22% or 40% depending on which training body you adhere to ... true/false?

My question is why?    I havenot been able to find any concrete reason for such
a edict, The Australian Navy use normal "O" rings in there breathing gear, this
includes dive equipment according to the civilan contractor that they use to
service thier stuff. What is wrong with normal "O" rings? I have been told that
such things as PTF tape (plumbers tape) which is used in an O2 environment is
simply the same tape that they normal use except that no oil is used in the
cutting process when it is shaved from the main roll. The use of O2 in a
hydrocarbon environment is common, just look at your local garage and watch the
way they use the oxy cutting gear in the worst oil bound conditions one could
find, they have no problems. I am not talking about O2 moving at speed and
under pressure, I understand the fire triangle what I want to know is why can't
I use normal "o"rings if they are O2 clean. What is it that makes them non O2
compatible? I have heard that NASA did a lot of work in this area in the
sixties but I can't find any printed results. Is the special "O" ring thing a
story put about by the Vitron manufactures?                                 all
a story pu about by the Vitron ring manufactores?
                                                                       hing all
a

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