OK this is a huge debate and has never been resolved to anyones satisfaction, its just that the reduced risk of DCS with high O2 deco outways the risk of an O2 fire in a reg. This IS possible and quite nasty when is happens, but is a rare event. (In these cases the regs where probably WAY OFF O2 clean!)
To be 02 service, something needs to be
O2 designed
O2 compatible
and
O2 clean.
OK the first one is interesting at the start of the popularity on Nitrox the industry made lots on money selling everyone funny coloursed 2nd stages for Nitrox up to 40%...
then came the 40% rule ie 0-40% O2 content is treated as air (and even whacked thru mineral oil compressors with no probs!) and the 41 to 100% as pure O2. Well there has to be a line somewhere.
Most manufactureres will not guarantee O2 designed regs for over 60% but we choose to take the risk.
Oxygen compatable material means that they burn at a higher temperature and generally last longer when exposed to high ppO2s - ultraviolet and seawater damaged actually overide this most of the time!
Oxygen clean is only a theoretical state. It means that all oparts have been tested for the absence of contaniments - fine but as soon as you touch it the things is not O2 clean anymore! It gradually becomes less clean the more use it has - industry standard is that you should have something O2 cleaned every 12 months - this may be too long in some circumstances!
I clean my deco regs everyfew weeks, also this solves any problems with o2 grease crystalizing.
get the popcorn out! shouldn't have started this!
Rod
