Re: [PSUBS-MAILIST] Deep Flight Challengers Interior

[irox <irox@ix.netcom.com>]

A double O-ring only makes sense if you have a leak
detector between the inner and outer O-ring and are
using it to detect when you need to abort the dive.

Otherwise you are just increasing the number of parts
to replace and the complexity of machining require to
manufacture the parts.  If the outer seals fails
before it's replacement schedule it has:

 - been designed wrong - and probably the inner seal
has as well. [This should never happen.]

 - not been replaced at a schedule inspection and has
rotted/failed - the inner seal was also probably not
replaced either. [This should never happen.]

 - has been damaged and did not get noticed during
inspection - and the inner seal is probably also
damaged.  This may happen, but it would be noticed
with in the first 30feet of the dive.

After 30feet or so of depth, the external pressure is
so much that it's all metal on metal (as Jay also states)
so the O-rings are no longer in use.

Cheers,
  Ian.


-----Original Message-----
>From: Brent Hartwig <brenthartwig@hotmail.com>
>Sent: Sep 1, 2008 6:19 PM
>To: PSUBSorg <personal_submersibles@psubs.org>
>Subject: [PSUBS-MAILIST] Deep Flight Challengers Interior
>
>
>Greetings Subbers,
>
>I've been looking for a picture showing the interior of the full ocean depth, 37,000 fsw designed sub, called the Deep Flight Challenger.  I found a very interesting one.  The dome looks to be severely fractured and held together with duck tape. The dome even looks like it might be made of glass.  Perhaps they tested it in the US Navy's pressure chamber and it didn't go well.  
>
>Also note the double O-ring grands on the hatch land.... ;)' 
>
>  I've gotten a fair amount of flack for wanting to use double O-rings for sealing my hatch against the hatch land.
>http://bp3.blogger.com/_FlxDEKxj5U4/R8IeBNG7yII/AAAAAAAAACw/af_AI6qySU8/s1600-h/DSCN1308.JPG
>
>
>Your resident day or night dreamer   ;)'     It of course depends on which side of the planet your on..
>
>Regards,
>
>Szybowski




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