CO2 systems

CARBON DIOXIDE FIRE SUPPRESSION
SYSTEMS EXTINGUISHING AGENT

APPLICATION

Carbon dioxide extinguishing agent used in the systems which DAIG-TZ Ltd. is offering are engineered systems
is particularly useful for hazards where an electrical, nonconductive
medium is essential or desirable; where clean-up of other agents
presents a problem; or where the hazard obstructions require the use
of a gaseous agent.

The following are typical hazards protected by carbon dioxide
systems:


■ Printing presses
■Vaults
■ Open pits
■ Dip tanks
■ Spray booths
■ Ovens
■ Engine rooms
■ Coating machines
■ Process equipment
■ Hoods and ducts
■ Flammable gas or liquid storage areas

DESCRIPTION

Carbon dioxide is a plentiful, non-corrosive gas that does not support
combustion nor react with most substances. It has a low toxicity
classification by Underwriters Laboratories (Group 5a). It is commonly
compressed to the liquid state for storage and transportation in DOT
cylinders. Upon release, it discharges under its own pressure giving
the appearance of steam as its low temperature crystalizes water in
the air. For fire suppression purposes the discharge is designed to
raise the carbon dioxide concentration in the hazard. This removes
the free oxygen which supports combustion*, and results in fire
extinguishment. The resultant lack of free oxygen dictates that total
flooding hazards be evacuated immediately, and carbon dioxide from
local application be avoided by personnel.

PERFORMANCE

Carbon dioxide is an effective fire extinguishing agent that can be
used on many types of fires. It is effective for surface fires, such as
flammable liquids and most solid combustible materials. It expands at
a ratio of 450 to 1 by volume. Other desirable attributes are its high
degree of effectiveness, its excellent thermal stability, and freedom
from deterioration. In addition, carbon dioxide has so many additional
commercial uses that refills are available in practically every large city
or seaport throughout the world. Criteria for quantity and concentration
of carbon dioxide is developed in NFPA-12 for both local and total
flooding applications.

*Certain materials do exist which contain their own oxygen supply (such as cellulose nitrate).
The exclusion of oxygen by carbon dioxide is not effective in the extinguishment of fires
involving these materials.

PROPERTIES OF CARBON DIOXIDE

The following are the properties of the agent:
Chemical formula CO2
Molecular weight 44.011
Normal sublimation temperature at

atmospheric pressure, (°F) –109.21
Triple point temperature

(at 75.35 psia) (°F) –69.88
Critical temperature, (°F) 87.87
Critical pressure, (psia) 1069.96
Critical density, (lb. per cu. ft.) 29.21
Density of liquid at 86 °F, (lb. per cu. ft.) 37.3
Specific volume of saturated vapor at 5 °F (cu. ft. per lb.) 0.266
Specific heat of liquid at 86°F, (btu per lb. °F) 2.5
Specific heat ratio (cp/cv) of vapor at 86 °F and one atmosphere pressure 1.3
Thermal conductivity, (btu ft. per sq. ft. hr. °F):
Saturated liquid, at 5 °F 0.067
Saturated liquid, at 86 °F 0.041
Vapor, at saturation pressure at 5 °F 0.0139
Vapor, at one atmosphere pressure at 86 °F 0.0169
Viscosity, (Centipoises):
Saturated liquid at 5 °F 0.13
Saturated liquid at 86 °F 0.065
Vapor at saturation pressure at 5 °F 0.013
Vapor at one atmosphere pressure at 86 °F 0.015
Relative dielectric strength of vapor at ambient temperature and one atmosphere pressure
(Nitrogen = 1) 0.88
Color Clear and water white
Flammability Non-flammable
Toxicity, Underwriters

Laboratories classification Group 5a

Quality criteria for initial and recharge are as follows:


The vapor phase shall not be less than 99.5% carbon dioxide with no
detectable odor.
The water content of the liquid phase shall not be more than 0.01% by weight (–30 °F dew point).
Oil content shall not be more than ten parts per million by weight.

ORDERING INFORMATION

Carbon dioxide cylinders for use in engineered systems may be
ordered in 50, 75, and 100 pound sizes.