Re: [PSUBS-MAILIST] Ambient Pressure (No Subject)

[Brent Shaw <drydivenz@yahoo.com>]

Pierre

After reading this I believe you could be heading for
danger and not being able to enjoy the scenery because
you'll be working to hard.

What I see as being dangerous is if any water comes
into the hull, displacement changes and the sub will
go down. Watching a clear hose I think would not be
the right way the control of inside hull pressure
although it would work and is very simple.

Driving along in your sub you'll be constantly turning
ball valves on and off as well as steering. I see that
as a lot of work and any little slip up and you could
crash.

Just my two cents worth and I'm no expert

On the hose going out of the hull run a one way check
valve.

For air into the cabin run a 1/4 push air switch.
These 1/4 air switches run 900 liters per minute
@100psi
Or you could go for a polit operated regulator to make
the system automated.

Run two 60psi gauges. one for outside hull pressure
and the other for inside hull pressure.

I would also go for a flow meter. Comments about
surfacing to refresh the air don't gel right with me
at all.


Brent







--- David Buchner <buchner@wcta.net> wrote:
> 
> On Monday, Mar 24, 2003, at 19:40 US/Central, Pierre
> Poulin wrote:
> 
> > I only have a hole at the bottom of the sub with a
> ball valve and a 
> > piece of clear tubing that goes to the top and
> down to the bottom of 
> > the sub. The end of the hose is open-. I also have
> another ball valve 
> > that provide compressed air from a cylinder into
> the hull. So the 
> > principle is very simple. If there is not enough
> air comming in the 
> > sub to equalize the pressure, water will want to
> go into the sub by 
> > the clear hose. I will see it gooing up and I will
> open the compressed 
> > air valve to augment pressure inside the hull. If
> there is to much 
> > compressed air comming in the hull, I don't care
> because the excess 
> > will go out by the hose. The end of the hose is at
> the bottom of the 
> > sub to expulse water that might comme into the sub
> and to expulse co2 
> > which is heavyer that o2.
> 
> That's the sort of simple way I might have come up
> with. But (and, 
> apologies if you've described this more in the past
> and I forgot) -- 
> does this arrangement respond fast enough during
> descent and ascent? I 
> guess: how big is that clear hose? What if you're
> rummaging in the 
> cooler behind you for another beer, and your shirt
> sleeve catches on 
> the dive plane stick, and you start ascending
> rapidly -- is there a 
> danger of higher pressure building up inside because
> you're rising 
> faster than the air gets out through your tube?
> 
> - - -
> 
> David
> buchner@wcta.net
> Osage, MN, USA
> http://customer.wcta.net/buchner
> 


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