Re: [PSUBS-MAILIST] air pressure

[Thijs Struijs <thijs-struijs@planet.nl>]

Michael,

I thought that pressure compensation with air was common practice. Can it be
done savely to a depth of 100 mtr? There is plenty of compressed air in a
sub. Nitrogen or CO2 would mean another thing to monitor, replenish and
worry about.

Btw, welcome to the list Matt.

Thijs Struijs
----- Original Message -----
From: "Michael Wludarczyk" <divedawn13@hotmail.com>
To: <personal_submersibles@psubs.org>
Sent: Tuesday, April 15, 2003 5:32 PM
Subject: Re: [PSUBS-MAILIST] air pressure


> Hi Matt,
> your idia of filling the container with 300 PSI is good, as long as you
> don't use air: 300 PSI is about 20 bars, = estam. 200 meters in depth.
> Air has a partial pressure of oxygen 0,20 / PPO2=0.20 X 300 PSI = 2.0
> that is quiet high for batteries and sparks, and it is volantile.
> So fill the batterie pod with nitrogen or co2. Or use gel cell bateries
and
> fill the pods with a light oil.
> best regards:
> Michael Wludarczyk. Commercial Diver and Submersible Pilot.
>
>
>
>
>
>
>
> >From: "Dan H." <JMachine@adelphia.net>
> >Reply-To: personal_submersibles@psubs.org
> >To: <personal_submersibles@psubs.org>
> >Subject: Re: [PSUBS-MAILIST] air pressure
> >Date: Tue, 15 Apr 2003 08:29:36 -0400
> >
> >Matt,
> >
> >If you charge the container to 300 PSI and sink it to a depth that
> >corresponds to 300 PSI there is no problem.  All forces are equal.
> >But, you can't safely say that a container that will handle 300 PSI of
> >internal pressure will withstand 300 PSI of external pressure.
> >The plastic soda (pop) bottle example has been used here many times.  It
> >will withstand the pressure of the carbonated beverage internally but
will
> >begin collapsing in only a foot of water if empty.
> >
> >Filling the air space you described in your previously posting in tried
and
> >true.  What's usually used as a filler is a nonconductive oil.  Basically
> >replacing the compressible air with a virtually non compressive liquid.
> >
> >Dan H.
> >
> >----- Original Message -----
> >   From: JackThraven13@aol.com
> >   To: personal_submersibles@psubs.org
> >   Sent: Tuesday, April 15, 2003 12:17 AM
> >   Subject: Re: [PSUBS-MAILIST] air pressure
> >
> >
> >   Hey, and another thing, on a more appropriate thread, sorry to post
> >again so soon.
> >
> >   Is it reasonable to expect a container that can hold a certain PSI to
> >resist crushing were that same PSI to be exerted on it's outer surface?
For
> >example, an air tank that can hold 300 PSI, would it withstand being
> >submerged to a depth that exerts 300PSI on it's outer surface?
> >
> >   Just a thought,
> >
> >   ...Matt
>
>
> _________________________________________________________________
> STOP MORE SPAM with the new MSN 8 and get 2 months FREE*
> http://join.msn.com/?page=features/junkmail
>
> ================================================================
> Deze e-mail is door E-mail VirusScanner van Planet Internet gecontroleerd
op virussen.
> Op http://www.planet.nl/evs staat een verwijzing naar de actuele lijst
waar op wordt gecontroleerd.
>