Liquid CO 2

[McMark]

Does anyone here know what the gas pressure in a commercial liquid CO 2 system is?

[Zrexxer]

Depends on temperature. At about 55° F, vapor pressure is about 650 psi. As temperature goes up, so does vapor pressure. At 70° F it's about 830 psi.

[Roger]

http://www.reefscapes.net/articles/b...co2_tanks.html
http://www.teamonslaught.fsnet.co.uk/co2_info.htm

[usmcpop]

Aah, but what is it at elevated temperatures? Inquiring minds want to know... we had a discussion here a couple years back. I never could find reliable data on CO2 pressure when it becomes supercritical.

EDIT: I should have checked the links above before I replied. One says "...It is unclear to science what state of matter the CO2 would be said to be in at and above this point - gas or liquid. At or above these temps, all bets are off as far as guessing the fluid behavior and/or the gas pressure of the CO2 inside the cylinder..." Good. I may be confused, but I am am in good company.

[Roger]

Don't know about critical pressure and temperature of CO2. I know full weight of cylinder should leave 10% by volume gas space at top of bottle so expanding liquid can't damage cylinder as temperature increases.

Readings on the red line shows the pressure change with temperature for a correctly filled bottle.
@ 100 degrees F the pressure in full bottle will have risen to 1400 psi ... @ 120 degrees F it's approaching 2000 psi

All CO2 cylinders I remember seeing were rated at 1800psi and hydro pressure is normally 1.5 times max pressure which is also what blow out plugs relieve pressure. All these pressures should be selected so it is safe to use. Blowing a blow out plug sounds like loud gun followed by roar of gas flow. I can tell you very scary if your 1 foot away.

[calweld]

Does anyone here know what the gas pressure in a commercial liquid CO 2 system is?

Is there a reason for this question????? If you'd elaborate a little more, you'd probably get a few more pertinent answers, plus many more UNpertinent answers .....

[Roger]

Are you asking about pressure of liquid CO2 in aCryogenic Liquid Cylinder at very low temprature? That pressure is governed by relief valve setting. Even if your not using CO2 a little is bolling off keeping CO2 cold in Dewar.

This link has some good tails.
http://www.thekrib.com/Plants/CO2/co2-rocket.html