shop-talk
[Top] [All Lists]

RE: I'm not, but Why can't I

To: <shop-talk@autox.team.net>, <keithka@microsoft.com>
Subject: RE: I'm not, but Why can't I
From: "Tim Mullen" <Tim.Mullen@trw.com>
Date: Tue, 29 Jan 2002 12:15:03 -0500
>>> "Keith Kaplan" <keithka@microsoft.com> 1/28/2002 11:45:32 PM >>>

> Seems like the low pressure would be perfect for breathing, too.  By 
> being a few psi above atmospheric, a leaky mask wouldn't be dangerous.  
> (I'm not a diver, so I don't know what pressure you want the air at to 
>breathe, 
> but I bet it's close to HVLP pressure.)

It's been a few years, but...

SCUBA tanks are pressurized to high pressure (I remember around 2,000 psi).  
The regulator on the tank lowers the pressure to a relative pressure of around 
100 psi, which feeds to the hose and the "face" regulator that goes into your 
mouth.  This second regulator reduces the 100 psi to atmospheric pressure 
(relative to the depth that you are swimming).  Basically, the air into you 
mouth 
is at zero relative pressure.  You breath in, and the slight vacuum on a 
diaphragm 
in the low pressure regulator releases the air into the mouth piece via a valve 
actuated by the diaphragm.  You breath out, and the air flow pushes the 
diaphragm, 
closes the valve, and the air is exhausted via one way flapper valves.   Long 
way of saying, no air pressure difference at all for divers.

But...   I can tell you that a half a PSI is a bit of air for breathing...  I'm 
one of those 
people that stops breathing when I sleep (sleep apnea), apparently I have a 
severe case.  That's why I have a very annoying "breathing machine" (CPAP -
Continuous Positive Air Pressure) that feeds air into a "nose" mask while I 
sleep.
I did the math once, and the machine creates about 0.2 psi which is still quite 
a 
bit of air flow that leaks out of my mask.

That is one solution for everyone.  If you snore a lot, and stop breathing 
while you
sleep, then maybe you could get your health insurance to buy you a CPAP 
machine...   8-)

Tim Mullen

Chantilly, VA
72 Lotus Elan Sprint
94 Miata R Package

///  unsubscribe/change address requests to majordomo@autox.team.net  or try
///  http://www.team.net/mailman/listinfo
///  Archives at http://www.team.net/archive/shop-talk


<Prev in Thread] Current Thread [Next in Thread>