"Pete C." wrote in message
ster.com...

Grumpy wrote:

"bart" wrote in message
...
Hi all,

I hope I'm not too way off base here in asking for advice, but you
guys seem to know everything!! :-)


Boss at work bought a $99.00 environmental chamber and told me to
"make it work".
( this one's sibling:
http://cgi.ebay.com/AES-ENVIRONMENTA...8 6.m20.l1116)

When we recieved it, it didn't "do" anything.
I kept flipping the switch back & forth and eventually some sticky
relays started "working", that is, the heater /fan started working and
the gas solenoid clicked in - depending on the temperature dial.

A label on the back says it is to be cooled with liquid CO2.
Somebody retrofitted it with a 300PSI solenoid - We have since then
gotten a 1000PSI liquid CO2 solenoid.
The wiring in it is OLD and BRITTLE, BTW.

A few hours ago my boss is on my ass to get the cooling working by
next week.
Now I have a basic oxy/acetylene rig at home, but have never played
with liquid CO2.

I'm not exactly sure of what fittings/tubing to use ( copper,
stainless, double flare??).

Also, the boss says that CO2 isn't toxic, so therefore we aren't going
to vent it.
(it's setup in the back of a kitchen, where I work {our "lab"}- with
zero ventilation)

I don't mind doing potentially dangerous stuff in my own garage ( with
the door open), but this is an office full of people.

Am I way off base telling him to hire a professional to do the gas
fitting ( and leave the premises when he runs it without ventilation?)


Just wanted another opinion.

(And yes, I am looking for another job)



Thanks in Advance!
B

CO2 can be dangerous.

I spent a lot of time as an engineer in the brewing industry,and we
worked
with it all the time. The 1000psi solenoid is pretty low as co2 can
reach
1200 psi on a hot day. We used conventional steel pipe and flaged
fittings,
but as you are only using small sizes flared stainless steel would
probably
be appropriate.

I would suggest SS tubing and the Swage-lock fittings to avoid the
tooling hassle of flared fittings.


Vent the room or you may kill someone


Yes you're right. We also used those to good effect and they were easier to
use.
As some of our lines were 2" those were always welded and flanged. We kept
the liquid at about minus 30 Deg Fahrenheit so the pressure ran about 300
PSI if I remember correctly. It was handy to have a few tons of liquid CO2
around if you wanted a shrink fit on anything. We'd expand it through a rag
stuffed into a reducing bush. Instant dry ice.
It would cool things down to about minus 50.