"Steve B" wrote in message
...

wrote in message
...
On Sat, 7 Apr 2012 19:52:52 -0700 (PDT),
rangerssuck
wrote:

On Apr 7, 10:41 pm, "Steve B"
wrote:
I'm interested in building a surface supplied
air compressor for two divers.
22 cfm@150 psi. I know that the big
difference is vegetable oil in the
crankcase vs. petroleum based oil, but just
wondering if anyone had any
experience with this. A new one especially
made for diving is going to run
about $7500, and one could be put together
from components for less,
provided the air generating part is
compatible with breathing air.

Anyone?

Steve

Just guessing here, but I imagine that a large
part of that $7500 is
going to lawyers and product liability
insurance companies. Are you
building this for someone who will NEVER sue
you? You may want to
think about consulting with a lawyer and an
insurance broker before
you get too involved with this project.

That said, have you looked at used and/or
surplus equipment? A quick
glance at Google turned up a bunch of stuff -
much oif it is SCUBA
(5000 psi), but there are definitely some
diving compressors out
there.
One of the big problems with compressors used
for breathing air is
carbon monoxide. Temperatures can be high
enough for CO to be formed
in tiny amounts. When CO is breathed it sticks
to hemoglobin better
than oxygen so it builds up in the blood.
Besides being a poison in
itself it also displaces oxygen in the blood.
So even tiny amounts can
eventually kill you. At depth the partial
pressure goes up so the CO
is absorbed even faster. The filters used with
breathing air
compressors remove CO along with other
contaminants. Having
experienced bad air once from a dive shop I
wouldn't risk a DIY
compressor.
Eric

Having been a HeO2 diver, rack operator, mixed
gas operator, being a federally certified
hyperbaric chamber operator, and having years of
training, I shall take your very slight bit of
information under advisement. I shall attempt to
delve through the layers of negativity, and if I
find any pertinent questions, answer them.
Okay, I'm off now ............. dive in
........... 'DIVER LEAVING
SURFACE".....................

Steve
steveb admits he is an operator, not a designer!