Mailing List Archive Mailing List Archive
At 01:05 AM 14/07/1998 -0400, Hidetaka Mizohata wrote: >Dear All: > >I recently heard that ANDI advocates the mandatory use of an O2 clean reg if >the tank contains 23.5% of O2 or more. I also heard that they go so far as >to install only the DIN valves on O2 clean tanks; this way a diver wouldn't >be able to use a non-O2-clean reg (yoke in this case) even when the gas >contains less than 40% O2. Who told you this stuff? >Does anybody know if and why ANDI advocates these >"rules" even if NOAA, NASA, OSHA, etc. say it is not necessary to use clean >regs as long as there's 40% or less of O2 in the mix? Is this "DIN-only for >nitrox tanks" rule enforced by all ANDI branches, or is it limited to some >parts of the world (i.e., Australia and Japan)? Are there other agencies >besides ANDI that do the same? Has there been any incident of cylinder >explosion because a non-O2 clean reg was used on EAN40 or less? Exactly how >did they (NOAA, OSHA, etc.) come up with this 40% rule? I know all of this >sound absurd at best, but one guy in Australia insists it is a legitimate >way to do nitrox and told me that I didn't know what I was talking about >when I said it's unnecessary to limit nitrox to a particular type of valve. I think ANDI Australia's policy says "follow manufacturer's recommendations when it comes to 02 cleaning". Although there are no 'rules' about the DIN valve and nitrox, consider this: The DIN valve, in Australia, is a convenient way to identify and segregate the rental nitrox tanks and regulators from the standard air rental equipment (which have yoke valves) in a busy dive shop. The DIN valve cylinders are 02 cleaned so they can be partial pressure filled -i.e. pumped with pure 02 then topped with air. The rental DIN regs are kept O2 clean so they can be used on any nitrox cylinder over or under 40% O2. Isn't this a simple system? Especially for a busy training facility. Your use of the word 'mandatory' is totally off. Customers with their own gear aren't made to follow the DIN/Yoke system. They just have to a) keep their nitrox cylinders and regs clean and b) not use their air cylinders and regs with nitrox. Sensible, yes? That 40% 'rule' seems problematic. Do you have to have one set of regs for up to 40% and one set for over? How inconvenient for deco regs. Why not keep 'em all 02 clean so you can use 'em with any deco mix? Then you don't have to worry about any of this under and over 40% stuff. All my cylinders and my manifold are 02 clean. My DIN deco regs are 02 clean - crystolubed and viton o-ringed. My DIN mix regs are not 02 clean (though they are clean and viton o-ringed). Nobody at the ANDI dive shop gives me a hard time. Common sense seems to take precedence to 'rules'. bless you all with a fervour that brings tears to my eyes & rgrds billyw -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
Navigate by Author:
[Previous]
[Next]
[Author Search Index]
Navigate by Subject:
[Previous]
[Next]
[Subject Search Index]
[Send Reply] [Send Message with New Topic]
[Search Selection] [Mailing List Home] [Home]