Seems too me that the Oring was either the wrong type or got damaged on 
install. I take pains to make sure that the neck area is free of 
corrosion and I spit on the Oring to give it a little bit of lube right 
before screwing down the valve. I then use a rubber mallet to snug it 
down.

This is also why I prefer to screw in the valves and then install the 
isolator rather than spinning one tank onto an assembled manifold, you 
can feel if the Oring is binding as you screw down the valve. George, out 
of curiosity were you using a viton or "O2 clean" Oring? What procedure 
did you use to install your valve?

 Jim

Sender: Art Greenberg  Date: 1/15/99 3:49 PM

>On 15 Jan 99 at 20:24, you wrote:
>
>> If you are doing required stop dives with a single it would be a
>> real good idea to bring a pony. Not a little one either. The pony
>> should be large enough to permit the return trip to the line and any
>> required deco. If you try to get by with less you are risking your
>> neck bigtime.
>
>I think we've excluded planned deco dives from this discussion.
>
>>  The other day I filled my HP 100 cu.ft. tank with 3500 psi.. I
>> put the tank on the boat in the shade. In about half an hour it
>> started to leak from the tank O-ring (the O-ring between the tank
>> and the valve). After leaking for about 2 min. half the O-ring blew
>> out. I have never seen one of these O-rings blow before. It was
>> visualed and the O-ring was replaced by myself 4 mo. ago.
>
>This is interesting, and the first case of anything like this I have
>heard about (I'm certain there are others, but equally certain its
>quite rare). How do you figure the O-ring came flying out? There's
>normally no gap between the valve and cylinder where that could
>readily happen unless the valve wasn't turned all the way in. Could
>the O-ring have been defective, damaged or just not installed
>correctly? How carefully did you inspect the O-ring before
>installing it?
>
>> If this occurred at depth the air would have drained out but quick
>> and if this was your sole air supply with a Y valve, you better find
>> a buddy with lots of air to save your butt.
>
>Yup, no argument, this is one of those failures that is covered by 
>another team member.
>
>How long did it take for the cylinder to drain?
>
>While I'm thinking about this ... would the cylinder empty faster at 
>depth than on the boat? If so, why?
>
>Art Greenberg
>artg@ec*.ne*
>--
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>


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