Los Angeles Water Fire Extinguishers
Water fire extinguishers are made for specific use, generally discharging a foamy liquid generally created to extinguish Class A fires such as organic solid material such as wood, Class B fires that involve liquid such as gas and oil, and Class C fires that involve electricity.
Wikipedia states, “Water cools burning material.”
“APW (Air pressurized water) cools burning material by absorbing heat from burning material. Effective on Class A fires, it has the advantage of being inexpensive, harmless, and relatively easy to clean up. In the United States, APW units contain 2.5 gallons (9 liters) of water in a tall, stainless steel cylinder. In Europe, they are typically mild steel lined with polyethylene, painted red, containing 6–9 liters (1.75–2.5 gallons) of water.
Water Mist uses a fine misting nozzle to break up a stream of deionized water to the point of not conducting electricity back to the operator. Class A and C rated. It is used widely in hospitals for the reason that, unlike other clean-agent suppressants, it is harmless and non-contaminant. These extinguishers come in 1.75 and 2.5 gallon units, painted white in the United States and red in Europe.
[edit] Wet chemical and water additivesWet Chemical (potassium acetate, carbonate, or citrate) extinguishes the fire by forming a soapy foam blanket over the burning oil and by cooling the oil below its ignition temperature. Generally class A and K (F in Europe) only, although newer models are outfitted with misting nozzles as those used on water mist units to give these extinguishers class B and C firefighting capability.
Wetting Agents Detergent based additives used to break the surface tension of water and improve penetration of Class A fires.
Antifreeze Chemicals added to water to lower its freezing point to about −40 °F. Has no appreciable effect on extinguishing performance.”
