my chapter 7 portable fire extinguishers

Aqueous Film Forming Foam (AFFF)

A water-based extinguishing agent used on Class B fires that forms a foam layer over the liquid and stops the production of flammable vapors.

5 classifications of fire extinguisher

A,B,C,D,K

extinguishing agent

Any substance used for the purpose of controlling or extinguishing a fire.

Dry Powder Extinguishers

Are used on Class D combustible metals fires. They form a solid crust over the burning metal. Most common powder used is sodium chloride.

carbon dioxide extinguishers

Both handheld and wheeled. Most effective in extinguishing Class B and C fires. Because their discharge is in the form of a gas, they have a limited reach and the gas can be dispersed by wind. They do not require freeze protection. Stored under its own pressure, discharge is usually accompanied by dry ice crystals or 'snow'. The CO2 displaces the oxygen and smothers the fire. No cooling effect or vapor suppressing film. CAUTION: When CO2 is discharged, a static electrical charge builds up on the discharge horn. Touching the horn before the charge has dissipated can result in shock.

Halogenated Agents

Chemical compounds (halogenated hydrocarbons) that contain carbon plus one or more elements from the halogen series. Halon 1301 and Halon 1211 are most commonly used as extinguishing agents for Class B and Class C fires. Also called Halogenated Hydrocarbons.

Class D fires

Combustible metals, magnesium, potassium, titanium and zirconium.

stored pressure

Compressed air or inert gas within the container forces the agent out a nozzle at the end of a hose when the operator presses the handle.

Class C fires

Electrical equipment, all fires involving energized electrical equipment.

stored pressure water extinguisherswat

Extinguishers that have stored Air and Water combined to put out Class A fires

Class B fires

Flammable liquids, hydrocarbon, alcohol based liquids and gases that support combustion.

saponification=-0

Forming an oxygen-excluding soapy foam surface, a phenomenonthat occurs when mixtures of alkaline basd chemicals and certain cooking oils come into contact resulting in the formation of a soapy film.

Class C rated extinguisher

Has no specified fire extinguishing capability test, because class C electircal fires are generally class A and B fires involving electricity.The extinguishing agent is tested for electrical nonconductivity.

water mist

In the fire service, water mist is associated with a fire extinguisher capable of atomizing water through a special applicator. Water-mist fire extinguishers use distilled water, while back-pump type water-mist extinguishers use ordinary water.

pump type water extinguishers

Intended for use on small Class A fires only. Equipped with either a single or double acting pump.

P.A.S.S

Pull, Aim, Squeeze, Sweep (proper procedure for using an extinguisher). Approach the fire from the windward side, wind at your back.

Water-Mist Stored-Pressure Extinguishers

Similar in appearance to standard stored-pressure water extinguishers, water-mist extinguishers use deionized water as the agent and nozzles that produce a fine spray instead of a solid stream. Because it is the impurities in water that make it electrically conductive, the deionized water also makes these Class A extinguishers safe to use on energized electrical equipment fires (Class C). The fine spray also enhances the cooling characteristics of water.

portable fire extinguishers

Some of the most common fire protection appliance, found in residence, retail stores, and businesses. intended to be used o b small fires in the incipient or early growth phase.

Class D Rating

Test rating varies with type of combustible metal being tested.

manual pump

The operator physically applies pressure to a pump that increases pressure within the container, forcing the agent out a nozzle at the end of a hose.

Deionized water

Water from which ionic salts, minerals, and impurities have been removed by ion-exchange.

extinguishing agents

agents that work by smothering are ineffective on materials that contain their own oxidizing agent. i.e a fire in magnesium or other combustible metals will flare and intensify of water is applied.

corrosiv

capable of causing corrosion by gradually eroding rusting or destroying a material.

Class A rating fire extinguisher

class of portable fire extinguishers that are rated from 1-A to 40-A. this class is primarily based on the amount of extinguishing agent and the duration and range of the discharge used in extinguishing test fires.1-A rating requires 1.25 gallons or 5 litres.

Pressure Cartridge

compressed inert gas is contained in a seperate cartridge on the side of the container. when the operator punctures the cartridge the expelland enters the container forcing the agent out a nozzle.

Clean Agent Extinguishers

developed to replace halogenated extinguishing agents.

smothering

excluding oxygen from the burning process

dry powder

extinguishing agent suitable for use on combustible metal fires.

NFPA 10

fire extinguishers be inspected at least once each year to ensure they are accessible and operable.

Class A

fires involving ordinary combustibles such as textiles, papers, plastics, rubber,and wood. fuels can be easily extinguished with water, water based agents such as Class A foam, or dry chemicals.

water chemical stored pressure extinguishers

intended for use on class k fires involving cooking fats, greases and vegetable and animal oils in commercial kitchens.

chain breaking

interrupting the chemical chain reaction in the burning process

class K

involve combustible cooking oils such as vegetable or animal fats and oils that burn at extremely high temperatures.while most of these fuels are found in commercial and institutional kitchens and industrial cooking facilities, they can also be found in private homes

Class C

involve energized electrical equipment. because water and water based agents will conduct electrical current, they cannot be used in class C fires until the electrical energy has been removed. class C extinguishing agents will not conduct electricity making them suitable for electrical fires. Once the power supply has been turned off or disconnected the fire can be treated as a Class or B fire.

Class B

involve flammable and combustible liquids and games such as alcohol, gasoline, lubricating oils, and liquefied petroleum gas (lpg). Agents used to extinguish special hazard class B fires are carbon dioxide, dry chemical, and class b foam

Class D

involving combustible metals and alloys such as lithium,magnesium, potassium, and sodium. Some common uses of magnesium are in wheels and transmission components for automobiles and even some metal box springs in beds. These types of fires can be identified by the bright white emissions during the combustion process.

Class K fires

kitchen fires, unsaturated cooking oils in well insulated cooking appliances located in commercial kitchens.

all portable fire extinguishers expel their contents using one of the following mechanisms

manual pump, stored pressure, pressure cartridge

Class K Rated extinguisher

must be capable of saponifying (converting the fatty acids or fats to a soap or foam) vegetable oil, peanut oil canola oil and other oils with little or no fatty acids.

Fire extinguisher care

never drop or throw, carry it diagonally across the body, do not remove the safety pin until ready to use, store securely , lay empty extinguisher on it's side, do not store or stack items in front of, shake dry chemical extinguishers monthly. use warm water and soap to clean monthly.

Class A Fire

ordinary combustibles, wood, paper, plastic, rubber and cloth

cooling

reducing the burning material below its ignition temperature

water type extinguishers

should be protected against freezing if they are going to be exposed to temperatures below 40'F, freeze protection may be provided by adding antifreeze or by storing in warm areas.

Class B Rated extinguisher

suitable for use on class B fires, classified with 1-B to 640-B. rated based on the approx square footage a non expert operator can extinguish using a full extinguisher.

wet chemical systems

system that uses a wet chemical solution as the primary extinguishing agent usually installed in range hoods and associated ducting where grease may accumulate.

Dry chemical extinguishers

used on class A, B, C fires and clas B-C fires, among the most common portable fire extinguishers in use today. there are two basic types. 1. regular b:c rated 2.multi purpose and A:B:C rated.