Water extinguishers

Impact damage occurred to one of 48 10 kg polypropylene tubs of calcium hypochlorite, each closed with a polythene lid, all supported on a wooden pallet and stretch-wrapped round the base with polyethylene film. The spilled material was swept up and discarded, and the pallet was moved to another part of the warehouse, and some 30 mins, later flames were seen at the base of the pallet [1]. Ignition was attributed to contact between residual solid hypochlorite on the pallet and lubricant drips on the concrete floor from fork lift traffic. Application of a dry powder extinguisher had little effect on the fire, but use of a 40 1 water extinguisher led to rapid escalation of the fire as contact between hypochlorite... 

Class A fire extinguishers are usually water based. Water provides a heat-absorbing (cooling) effect on the burning material to extinguish the fire. Pressurized water extinguishers use air under pressure to expel the water. 

Water exchange kinetics experiments, 13 433 Water, extinguishing capability of,... 

Pressurized water extinguishers should be hydrostatically tested to at least 200 psig (1,379 kPa). The design should provide automatic pressure release for safety upon disassembly. A listed fire extinguisher containing antifreeze agent suitable for the minimum expected temperature should be supplied when necessary. 

Steam-generating plants, air compressor plants, and similar plants should be provided with potassium bicarbonate dry chemical extinguishers (120-B C) for Class B or Class C fires in the areas containing hydrocarbons or other flammable liquids. For fires in electrical equipment, at least one extinguisher (10-B C) should be provided. If Class Afire hazards exist, multipurpose dry chemical extinguishers (20-A 80-B C) or water extinguishers should be provided. 

Water extinguishes a flame by wetting but also by absorbing much of the heat that the fire needs to sustain itself... 

One of the products of combustion is water. Why doesn t this water extinguish the combustion ... 

Fire protection systems-sprinklers, adequate water, extinguishers (halocarbons, CO ... 

Water is by far the most commonly used fire suppression material and one of the most effective. However, it is important that water not be used on fires involving electricity or flammable liquids. Most flammable liquids are less dense than water and will continue to burn while floating on top of the water. In these situations, the water serves only to spread the fire and will never effectively remove the heat as intended. Since water will also conduct electricity, there is the potential of electrocution should a water extinguisher be used on an electrical fire. Water extinguishers are intended to extinguish fires in which wood, plastic, or paper are the primary fuels and should not be used on electrical or flammable liquid fires. 

Allow fire to bum out shut of the flow of gas and cool adjacent exposures with water. Extinguish (only if wearing a SCBA) with dry chemicals or carbon dioxide... 

The five elements are mutual conquest , which means Wood feeds Fire, Fire creates Earth, Earth bears Metal, Metal enriches Water, and Water nourishes Wood . Thus it is also true that safety feeds benefits, benefits create specters, specters bear accidents, accidents enrich institution, and institution nourishes safety in the context of coalmine production. The five elements are mutual overcoming , which means Wood parts Earth, Earth dams Water, Water extinguishes Eire, Fire melts Metal, Metal chops Wood . Thus it is also true that safety parts specters, specters dam institution, institution extinguishes benefits, benefits melt accidents, and accidents chop safety in the context of coal mine production. 

These are suitable for class A types of fire. They contain special additives and are particularly effective for cooling and penetrating the lire and can be up to 300% more effective than the ordinary jet water extinguisher. 

Water extinguishers are effective against burning papa- and trash (class A fires). These should not be used for extinguishing electrical, liquid, or metal fires. 

Class A For fires involving ordinary combustible materials, such as wood, paper, or clothing, where the quenching and cooling effects of water prove most effective, use a pressurized water extinguisher or ABC-type... 

Most laboratories do not use water (extinguishers) because fires with chemicals and electrical equipment should be extinguished with other agents. 

Water extinguishes a Class A fire primarily by cooling the burning fuel. Type A extinguishers are not likely to be found in laboratories. This removes the heat from the fire tetrahedron and the fire stops burning. (See Chemical Connection 2.1.2.1 Why Firefighters Love Water.)... 

Why are pressurized water extinguishers not found in chemistry laboratories ... 

Figure 25.14 Section through a water extinguisher. (Courtesy Thorn Security Ltd)...

Figure 25.15 Section through a stored pressure type of water extinguisher. (Manual of Firemanship. Courtesy Home Office)...

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