Ok, Here's the deal- this time last year (two years ago now) I had purchased a new AL 40 and a valve for it to use as an O2 bottle. I was meeting sme friends in Central FL to dive on a weekend, and my then SO offered to fill for me, since he was going to the shop anyway. He asked if I wanted totake the new 40, and I said yes, and I specified that it WAS NOT O2 clean yet. He said he would handle it. As we were in the parking lot of a cave system, I pressurized the O2 reg to check the bottle pressure (as always), when I heard a loud POP. it sounded like an O ring blew, and I assumed that was what happened, until I looked down as I was thinking "shut the valve down". It was then that I realized myhand was no longer anywhere near the valve, and the valve no longer had a knob. When I looked at my hand, there was a huge gash extending from the base of my index finger to the base of my middle finger and between the two. It had already begun to swel grotesquely. My buddy figured out there was a problem, loaded me ( and the gear- we were NOT leaving without the gear) inthe truck and we went to the nearest hospital- in Live Oak, FL. It took the ER staff 3 hours to debride my hand, most of which was spent picking out brass, sliver by tiny sliver. I left the hospital lucky to have 14 stitches in my hand. Thankfully, i still had my hand, and amazingly, there was no tendon or ligament damage.
You see, my then SO did NOT O2 clean the valve. He ASSUMED that since it was brand new it was O2 clean (he had made this assumption several times before, with no ill effect). It was not. Nearest we can reconstruct was that there was lubricant ont he seat which was not O2 compatible. The seat flashed, there was carbon all over my hand and sleeve (and inside the bottle). The force of the explosion (and it was a contained explosion) blew a hole in the brass valve stem large enough to stick a Qtip through- hence all the brass in my hand). The hard plastic knob disintegrated and formed a serrated edge which shredded my hand.
I have the valve peices (all we could find)- I use them as a teaching aid. I am lucky to be alive, much less still have both hands and all my fingers - amazingly- functioning! I thinkI still have pics of my hand somehwere- if anyone wants to see them I'll post them (they are pretty gory).
DO NOT TAKE O2 CLEANING FOR GRANTED. DO NOT TRUST SOMEONE ELSE TO DO IT FOR YOU.