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Essentials Of Fire Fighting Seventh Edition. Chapter 6 Portable Fire Extinguishers. Learning Objective 1. Distinguish among the five classifications of portable fire extinguishers. Portable Fire Extinguishers. Classified according to type of fire they are designed to extinguish
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Essentials Of Fire Fighting • Seventh Edition Chapter 6 Portable Fire Extinguishers
Learning Objective 1 • Distinguish among the five classifications of portable fire extinguishers.
Portable Fire Extinguishers • Classified according to type of fire they are designed to extinguish • Some are suitable for more than one class of fire; some only designed for a particular class • Should only be used for intended fire type(s) • Certain extinguishing agents are only effective on certain classes of fuels
Class A — Ordinary Combustibles (Cont.)
CAUTION • The use of water or water-based agents on Class D fires will cause the fire to react violently, emit bits of molten metal, and could injure nearby firefighters.
CAUTION • Use only Class D rated fire extinguishers to extinguish metal fires.
Class K — Combustible Cooking Oils Courtesy of Steven A. Stokely, Sr. and Midwest Kosher Deli, South Bend, IN (Cont.)
REVIEW QUESTIONS • List and describe the five classifications of fire. • How are portable fire extinguishers rated?
DISCUSSION QUESTION • Create a mnemonic device (memory device) such as an acronym or phrase to help you remember the five classifications of fire.
Learning Objective 2 • Distinguish among the various types of portable fire extinguishers.
Operational Characteristics Of Portable Fire Extinguishers (Cont.)
NOTE • Water-type extinguishers must be protected against freezing if exposed to temperatures lower than 40°F (4°C). Protection options include adding antifreeze to the water or storing them in warm areas.
NOTE • Some manufacturers market AFFF foam concentrates that can be used on Class A fires.
Clean Agent Extinguishers Courtesy of Ansul Corp.
CAUTION • When the extinguishers discharge carbon dioxide, a static electrical charge builds up on the discharge horn. Touching the horn before the charge has dissipated can result in a shock.
Dry Chemical Extinguishers (Cont.)
Dry Chemical Extinguishers (Cont.)
Dry Chemical Extinguishers — Handheld Units • Similar design to air-pressurized water extinguishers • Agent storage tank maintains constant pressure of about 200 psi (1 400 kPa) • Uses nitrogen or carbon dioxide pressurizing gas • Pressure cartridge connected to agent tank • Operator pushes plunger to release gas from cartridge and pressurize the tank • Uses nitrogen or carbon dioxide as the pressurizing gas
CAUTION • When pressurizing a cartridge-type extinguisher, do not place your head or any other part of your body above the top of the extinguisher. If the fill cap was not properly screwed back on, the cap and/or a cloud of agent can be forcibly discharged.
CAUTION • The top of the extinguisher should be pointed away from the operator and any other nearby personnel when pressurizing the unit.
Dry Powder Extinguishers (Cont.)
CAUTION • Water applied to a combustible metal fire results in a violent reaction that intensifies the combustion and causes bits of molten material to spatter in every direction.