Hi Bill,

> ----------
> From: 	Bill Wolk[SMTP:BillWolk@ea*.ne*]
> 
> On 8/30/01 Porter, Greg, Gregory.Porter@AR*.Bo*.co* wrote
> 
> >Given the possibility of having an undetected Oxygen flash while PP
> filling,
> >and given that the resultant Carbon Monoxide in the cylinder would be
> >tasteless, odorless, and lethal, is anyone testing fills with a CO
> detector
> 
> [snip]
> 
> Greg -
> 
> Before we get to the carbon monoxide detector, where did you come up with 
> the idea that there's such a thing as an "undetected Oxygen flash" in the 
> first place? 
> 
Heard it from a few different different divers and at least one dive shop
technician.  Didn't dream it up myself. If you know different give me your
experience.

> It sounds like another gas handling "monster in the closet story" foisted 
> on the diving public ... <snip>
> 
I assume from this statment that you don't know either....

> Would everyone out there who has experienced a "detected Oxygen flash" 
> please write Greg so he understands the magnitude of the problem he's 
> trying to "fix."  
> 
That was the original intent of the post.... not sure you're adding anything
constructive here nor that anyone needs your permission to provide input.
Again give your experience if you have any.

> Let's start at the beginning: oxygen is an oxidizer. It is not itself 
> combustible. For there to be an "oxygen flash," your tank already has to 
> be contaminated with something combustible  and that fuel has to ignite. 
> Have you ever found oil in your tanks when they've been VIP'ed? 
> 
No. I'm talking about O2 cleaned cylinders PP filled and topped off with
appropriately filtered air.

>  If so, I have a few tips for you that are more important than the CO
> detector:
> 
As the answer was no, the tips on dirty air are irrelevant.

> The key to safe technical diving -- call it DIR or not -- is to identify 
> *real* problems and to solve them as simply as possible. 
> 
Agreed

> Exaggerating problems that rarely exist in the real world and then coming
> up with 
> convoluted solutions to solve these non-existent problems makes diving 
> more dangerous, not less.
> 
Purely based on your post I'm still not sure that an undetected O2 flash is
an 'Exaggerated problem rarely existing in the real world"  because you've
provided no input to the contrary other than your assumptions.  Any real
experience you have in this regard would be meaningful input. 

It appears that all you're essentially saying is that CO contamination will
not occur if you have clean tanks and air fills. That's not the real world..
and that's not the attitude that PP filling is based on.

I'm certainly no expert (hence the post to the Lists) but my understanding
is that PP filling practices are based on the assumption that in this real
world the cleaning of tanks and air may not remove all the combustible
hydrocarbons.  Therefore we should PP fill the O2 very slowly just in case
there are HC's present.  Now let's say that we mess up and PP fill our O2
too fast and lets assume that we actually did have some HC's find their way
into our 'clean' environment... we have combustion which produces CO...
ordorless, tasteless, and toxic. 

Hopefully now we're on the same page.  So here are the pertinent questions:

- Is this so rare that we needn't worry about it ?

- Do we hear the combustion ?

- Is there an inexpensive, quick, and easy method to check for CO in the
final fill ?  

As intended in the original post and hopefully clarified here.... inputs
from those with experience are appreciated.

Best regards,
Greg

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