Carbon Dioxide | Fire extinguishing systems

Carbon Dioxide ( CO2) is a Standard Commercial Product with many other uses and it is readily available throughout the World. At normal temperatures and pressure Carbon Dioxide is an odourless and colourless inert Gas with a density of approximately 50 per cent greater than the density of Air. It is an Inert Gas, Non-Corrosive with no harmful effect on most materials. It will not contaminate foodstuff. It disperses leaving no material trace. It has great Dielectric strength and can be applied safely to live electrical equipment. It is discharged as Gas and it will penetrate into otherwise inaccessible positions. It provides its own pressure for discharging through Valves, Pipework and Nozzles. CO2 extinguishes fire by reducing the Oxygen content in the atmosphere to a point where it will not support combustion. Reducing the Oxygen content from the normal 21% on Air to 15% will extinguish most Surface Fires. For some materials, however, it must be reduced even lower. The dilution of the Oxygen in the Air, by the CO2 Concentration that will extinguish fire, may create atmospheres that will not sustain life. Such atmospheres will be produced in spaces protected by CO2 Total Flooding and may be produced by any large volume discharges drifting into adjacent low places. Persons rendered unconscious in these atmospheres can usually be revived without any permanent ill effects when promptly removed from such atmospheres. Large volume discharges of CO2 may seriously interfere with visibility during and immediately after the discharge period.It is therefore essential that all precautions are taken and the correct locking off procedures are followed as well as the system being well maintained. The pressure within the C02 Cylinder varies with changes in ambient temperature, the pressure increases with rising temperature. At 21° C ( 70° F) the pressure would be 850lb/ in2. Each Cylinder Valve incorporates a Safety Disc designed to rupture and discharge the CO2 contents at a pressure safely below the cylinders test pressure.Care must be taken, therefore, to ensure that the CO2 cylinders are not installed in a position where the temperature is likely to exceed 60° C ( 140° F) .
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