Re: [APD] Aquatic-Plants Digest, Vol 35, Issue 8

[Douglas Guynn <d_guynn at sbcglobal.net>]

I'm not sure why you experienced the effects you did when your tubing burst. I worked in a plant that extracted CO2 from a natural gas stream as part of a CO2 flood system in the Permian Basin oil fields in Texas. We shipped out over 600 gallons of liquid CO2 A MINUTE for re-injection into the Seminole-San Andreas formation. I was on shift one morning when a 3/8-inch fitting under 2000 psig of pressure (140 kg/cm2 for those on the metric system) broke loose and released a visible cloud of CO2 you could not see through. I experienced no ill effects of being directly in the cloud ( about 10' in diameter) and working to close some 24-inch (39 cm) valves to isloate the pump.
   
  I realize the cloud I saw was not the CO2, but the moisture in the air condensing to a visible state (like fog on a cool morning) due to the cooling effect of the expanding liquid.
   
  By the way, for those of you with OCD, the material in the bottom of your CO2 cylinder is TECHNICALLY not a liquid. It is a supercritical fluid (look that one up in your Funken-Wagnals). Just a little bit of information I learned a long time ago. Not really anything to get in a pissing contest about, just some little known trivia.

  
Madan Subramanian <madans at hathway_com> wrote:
  
I am not sure if CO2 has a characteristic smell, or some companies add 
something that gives out an odor to the gas, but I have had a CO2 tubing 
burst (at the connection to the solenoid valve, which is quiet hot), the 
pressure out of the regulator - 1.5 kg/cm2, it's almost impossible to 
get anywhere near the CO2 system and shut off the cylinder valve, I had 
to wrap a wet towel over my face to be able to do that, my nose was 
tingling for a while after I shut off the gas, this in my well 
ventilated open air balcony. It would be much more difficult to handle 
inside a room, worse inside a cabinet, the flexible tubing 
(silicone/airline) people use may not be able to handle the liquid-gas 
expansion.

A leak after the needle valve will be miniscule and can be easily worked on.

Anyway my system is piped to 5 tanks under 1.5kg/cm2 pressure, I use 
Polyurathane tubing ( max. pressure - 20kg/cm2) to pipe the gas, to the 
individual needle valves next to the aquariums. It will not be the case 
with many people.

Anybody know of CO2 regulators that limit the flow of gas through them? 
The welding regulators we use do not limit the gas flow. ;-)

Keep the cylinder upright, and you are safe. Have kids/pets around?, 
strap the cylinder to prevent it falling. The liquid-gas expansion and 
blah... blah.... well is just that. ;-)

Madan Subramanian
Bangalore, India.

> Again, one has to consider the effect of the flow rate. Fire 
> extinguishers typical are meant to dump lots of CO2 in a very short 
> time, pounds in just few miniutes art most. Gardeners' CO2 otoh, is a 
> miniscule flow rate.
> 
> It can be very safe to operate a fire extinguisher in an enclosed house. IN fact, it's the recommend corse of action in certain situations! ;-)
> 
> sh
> 
> 
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  Douglas Guynn
       PointForward, Inc.       5030 East University, Suite B-101
       Odessa, Texas 79762
       432.550.3331 (office)
       432.366.1879 (fax)
       432.559.4997 (cell)


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