HP 02 handling

[Akyla]

Greetings,

The very recent event discussed in the accidents forum involving the compromise and rupture of a deco bottle with 100% 02 got me thinking. This event occured in the divers garage and all of the details are not yet out, but apparently the bottle was knocked over and this caused the 02 to ignite. The amount of destruction was signficant and the injuries very severe.

This event caught my attention as I have been seeing a great increase in this exact type of bottle on board, usually ponys of 40cuft filled with 100%. Most of the advanced deco schedules call for a clean up with the 100% and the CCR units also have HP02 bottles as well so it is something that is not going to go away in the advanced and deep diving community.

I have been ensuring these small bottles were stored in what I thought was a safe place where they would not be subject to being knocked around but they are not "strapped down" there. I am now thinking that this may not be enough and something more secure might be in order as I do not wish to see this happen on my boat at sea.

• How are other dive boats handling this issue, if at all?
• Do you have anything like a rack for the small bottles to be secured in or just rack them in with the standard cylinders?
• Am I being too concerned about this or is it a real danger that may preclude having anything over 40% onboard except for the 02 kit?

Any thoughts?

 

[Wookie]

I have a confinement fill station for filling HP O2 bottles (we pump 40's and 80's and hp rebreather cylinders to the max rated pressure of the cylinder onboard, and have the capacity to fill O2 to 4500 PSI) We do not provide a rack, but if it is rough, we either attach the cylinders to the rebreather, or lay them under the dive bench. The whole thread and incident seemed a little hokey to me....

 

[Tortuga James]

Because of this incident, I will certainly be more diligent about knowing the content of the pony cylinders that come aboard and how they are stowed. I know I have in the past allowed pure 02 stage bottles on the boat and stowed them in the same manner as rec mixed gas ponies.

I have 4 18cf medical 02 bottles in my kit and they are very secure in a custom rack in the cuddy.

 

[Capt.Ed]

I was talking with the guy that does our Hydros yesterday and he heard about it too...he believes that 4000psi for 100% O2 is very dangerous and that the bottle was probably over pressurized (most medical grade bottles never exceed 2000psi) and when the bottle tipped over the stem (inside the bottle) sparked causing the explosion. He also stated, and I think it's true, that as you increase pressure the O2 becomes more unstable. I don't know enough about it to talk about it with any authority but it made sense when he explained it.