I think I would be afraid to dive with no scrubber or oxygen. What
would happen if I get tangled on something and can't get back up?
By the time anyone realizes I am in trouble I could suffocate.
Rick,
As of yet, I don't have a scrubber or O2 supply
in my sub. For now, I never stay down with two people in the sub over
twenty minutes. That's my rule. I set a timer and return to the
surface when it times out. So in actually, it's about thirty minutes
from closing the hatch to opening it again. There is a pretty good
cushion as I do it. Besides, my wife is more comfortable with me
touching base on a schedule like that. (she muttered something about
the! life insurance not being paid up or something) I had considered
an O2 tank when building my sub. It would be nice to extend my bottom
time.
Kittredge used to carry a 02 tank inside his
sub, and then after the space capsule disaster, he moved it outside and
piped the O2 in through a hull penetration to a valve in the sub.
I was debating when building my hull whether to put the through hull in or
not. My thoughts were and still are; a tank inside the hull is not
leaking or it would be empty. A tank outside of the hull would have to
be turned on before putting the sub in the water. The valve inside the
hull may be leaking a bit and I may not know.
Unless the tank or valve ruptures, I don't see
the danger of it being inside the sub. I know it's not leaki! ng O2 at
the time I'm in the sub if it has sat in there for a month or so
already. If I want to extend my bottom time with supplemental O2 and
discover my tank is empty I have to surface and go back to my twenty minute
schedule. I could carry two smaller medical tanks.
Any thoughts?
Dan H.
----- Original Message -----
Sent: Wednesday, January 11, 2006
9:41 PM
Subject: Re: [PSUBS-MAILIST] Life
Support
harry
The normal human consumes
about one cubic foot of oxygen per hour and will feel no effects of oxygen
deprivation at an o2 level above 18% the osha level is 19.5% minimum. air
contains 21 % o2. So dependent upon the size of your cabin you need to run
the numbers to see how much o2 you will have.
A co2 scrubbber can be
made from a piece of plastic pipe with screens at the end to hold the
absorbent. mount a fan at the top and for under 100$ you have! a co2
scrubber.
one caution when using
o2 addition it does make things burn rapidly. and abs says that o2
tank most be mounted outside.
fire and o2
the biggest problem using
pure o2 is the risk of fire in the system piping. high velocity o2 can
ignite lots of things . needle valves are used here. Trust me on this i
turned a rebreather in to a flame thrower the hard way.
most valves can be ordered o2 clean and
should be, the packing and grease needs to be o2 compatible. yes o2 needs
a special grease. piping will need to be cleaned prior to use. I have h!
ad success with hot soapy water wash, repeat until clean then hot water
rinse and cap lines until installed.
hope this helps
rick m
----- Original Message -----
Sent: Wednesday, Janu! ary 11, 2006
2:51 PM
Subject: [PSUBS-MAILIST] Life
Support
Hello
folks,
It has been a long time
since my last post but I still have questions!
Is it correct to think that
in an enclosed space, like your pressure hull you will suffer from the
negative effects of excess CO2 before you suffer from a lack of O2? What
I am get! ting at is, could you upgrade a simple sub with no life
support by adding just a scrubber to extend your usable bottom time or
would you only gain a little bit of extra time before the O2 would need
replenishing as well.
What sort of equipment is
used by those of you who do replenish the O2? It is sufficient to have
an O2 tank, conten gauge, regulator (and gauge?), and a flow meter (with
a separate O2 sensor and meter). Or does the equipment need to be more
sophisticated than this.
What do you do about ?o!
xygen cleaning? Do you have to just concentrate on the O2 supply kit or
all of the equipment within the sub?
How many of you provide
yourselves with CO2, O2, and internal pressure gauges to monitor the
environment but do not fit additional life support.
Thanks in advanced
guys,
Harry