That is a loaded question!
It will be impossble to keep this short and answer your whole question.
Fire suppression and extinguishment can be assited with a variety of tools. While I am sure taking this answer from a firefighter perspective would include a detailed list of tools like axes, kelly tools, shovels, ladders, etc., I am going to take a slightly different approach and catagorize fire extinguishing equipment into three catagories. Vehicular apparatus, portable equipment (including portable fire extinguishers), and fixed systems. Recognizing that the second can be, and often is carried on the first.
Vehicular apparatus -
This includes trucks, aircraft, or boats that have been equipped with the necessary tools for firefighting: Agent storage, pumps, distribution equipment, and any applicable tools needed. Obviously, depending on thier application these items will vary. Most aircraft use a chemical suppressant, but some do pick up and drop water.
http://www.photovault.com/Link/Technology/Aviation/eFirefightingAircraft/TAEVolume01.html
Most trucks use water as thier primary suppressant, but some are equipped to distribute chemical. Ansul's Magnum is a fine example of a chemical truck.
https://www.ansul.com/Products/lrg_handline/lrg_hline_magnum.asp
Most boats are equipped to simply pump the water they are floating on.
http://www.lafire.com/fire_boats/Boat2.htm
Portable Equipment-
This includes non-motorized or hand-portable firefighting equipment. The simplest example of which, I suppose would be a bucket of water or sand! Most portable fire extinguishers are either carried by hand or on a wheeled cart. These units can be charged with a variety of extinguihing media including water. Other common types are AFFF or other foam based, dry chemical, dry powder, liquid potassium mixture, or halogenated agent. The most common type of hand portable fire is the "ABC" dry chemical or monoamonium phospahte. Not all dry chemicals are effective on "A" class fires, so be careful. More about classes of fire at the end.
https://www.ansul.com/Products/hand_portable/images/redlinewheeled_app_02_z.jpg
Fixed Systems-
Fire suppression is often aided or accomplished by the use of fixed suppression equipment. Fire Sprinkler systems are the most common type. Most "wet" sprinkler systems have water in the pipes up to each sprinkler head. The sprinkler head usually has a glycerin filled glass bulp or metallic fusible link keeping the head closed. If the temperature gets hot enough to melt the link or bust the bulb, bingo, you get water. Dirty, nasty, stagnant water which is initially black from the pipe corrosion. Contrary to popular belief, only the head that fused releases water unless it is a very distinct kind of sprinkler system, referred to a deluge.
Other systems include Dry Chemical for paint spray areas, flamable storage, or fueling areas, Carbon Dioxide Gas systems for industrial processes and sometimes storage rooms, Halongenated or Inert Gas systems for labs, archive storage, switchgear, and computer rooms and wet-chemical for most commercial kitchen cooking hoods. There are also foam systems and water mist systems for special applications.
https://www.ansul.com/Products/co2_systems/images/co2_app_z.jpg
Which agent is right for the job?
This depends on the class of fire you are encountering. The classes and best agents are as follows:
CLASS A -
Fires involving wood, paper, trash, rubber, most plastics. With the exception of metal, almost anything "solid" falls into this catagory. The best agents to use is typically water or foam. ABC Mutipurpose Dry Chemical, and some larger halogenated agents can also work, but probably not as effectively. Carbon Dioxide, Class D powders, and Class K chemicals will not be very effective of this type of fire.
CLASS B -
Fires involving flammable gases and liquids. Gasoline, kerosene, industrial liquid chemicals, propane, and natural gas are all examples of class B flammable fuels. Water is not a great choice for class B fires, as most flammable fuels will float on the surface of the water and contiue to burn. Water could actually spread a Class B fire. Foam is your best choice, followed again by dry chemical and halogenated agents. CO2 can be effective, but may require you to get so close that it may be dangerous to use as a portable unit. CO2 also dissipates quickly.
CLASS C-
Class C fires are fire involving energized electrical equipment. Cutting the power to class C fires can assist with firefighting, but never assume that there isn't stored energy. Using water and water based media to fight class C fires can present a risk of electrical shock. Stick with the Dry Chemical, Halogenated Agents, or CO2 to fight electrical fires.
CLASS D-
Class D fires involve flammable metals, such as magnesium or lithium. These fires are burn extremely hot and are very difficult to extinguish. Class D Powders are typcially used to fight flammable metals fires. This powder is typically applied with a bucket and a scoop or with special hard portable extinguishers.
CLASS K-
Class K fires involve cooking oil fires, typically in a commercial setting. Class K extinguishers use a potassium and water based "wet-chemical" to exinguish the fire and are to be used in conjunction with the wet-chemical fire extinguishing systems in the cooking hoods. If you encounter a cooking oil fire at home, baking soda, or a class B fire extinguisher can work fine. Be careful not to "splash" the burning oil when figting the fire.
Phew! I told you that was alot. Check out this website for more information on classes of fire, firefighting, and hand portable fire extinguishers...
http://www.fireextinguisher.com
Feel free to contact me direct if you have more specific questions.
(I apologize for the spelling errors. Spell checker doesn't work when the document gets long like this.)
2006-06-26 06:43:16
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answer #1
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answered by todvango 6
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