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CLASSES OF FIRE

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CLASSES OF FIRE Class A combustible materials Characteristics deep seated, leave ash and embers. Extinguishing method cooling Class B ... – PowerPoint PPT presentation

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Title: CLASSES OF FIRE


1
CLASSES OF FIRE
  • Class A combustible materials
  • Characteristics deep seated, leave ash and
    embers.
  • Extinguishing method cooling
  • Class B flammable liquid, gases, greases and
    similar products.
  • Characteristic surface burning.
  • Extinguishing method cut off oxygen supply or
    prevent flammable vapor from being given off.
  • Class C electrical fires
  • Characteristic electrical shock
  • Extinguishing method use non-conducting
    extinguishing agent.
  • Class D combustible metal fires

2
Types of Portable Fire Extinguishers
Different types of fire extinguishers are
designed to fight different types of fires. The
three most common types of fire extinguishers
are
  • Air pressurized water extinguishers
  • Carbon Dioxide extinguishers
  • Dry Chemical Extinguishers

3
Air-pressurized water extinguishers
4
Air-pressurized water extinguishers
  • Water is one of the most commonly used
    extinguishing agents for type A fires. They are
    filled about two-thirds of the way with ordinary
    water, then pressurized with air. In some cases,
    detergents are added to the water to produce a
    foam. They stand about two to three feet tall and
    weigh approximately 25 pounds when full.
  • APWs extinguish fire by cooling the surface of
    the fuel to remove the "heat" element of the fire
    triangle.
  • APWs are designed for Class A (wood, paper,
    cloth, rubber, and certain plastics) fires only.

5
Air-pressurized water extinguishers
  • Never use water to extinguish flammable liquid
    fires. Water is extremely ineffective at
    extinguishing this type of fire and may make
    matters worse by the spreading fire.
  • Never use water to extinguish an electrical fire.
    Water is a good conductor and may lead to
    electrocution if used to extinguish an electrical
    fire. Electrical equipment must be unplugged
    and/or de-energized before using a water
    extinguisher on an electrical fire.

6
Carbon Dioxide extinguishers
7
Carbon Dioxide extinguishers
  • This type of extinguisher is filled with Carbon
    Dioxide (CO2), a non-flammable gas under extreme
    pressure. These extinguishers put out fires by
    displacing oxygen, or taking away the oxygen
    element of the fire triangle. Because of its high
    pressure, when you use this extinguisher pieces
    of dry ice shoot from the horn, which also has a
    cooling effect on the fire. You can recognize
    this type of extinguisher by its hard horn and
    absent pressure gauge.
  • CO2 cylinders are red and range in size from five
    to 100 pounds or larger.
  • CO2 extinguishers are designed for Class B and C
    (flammable liquid and electrical) fires only.

8
Carbon Dioxide extinguishers
  • CO2 is not recommended for Class A fires because
    they may continue to smolder and re-ignite after
    the CO2 dissipates.
  • Never use CO2 extinguishers in a confined space
    while people are present without proper
    respiratory protection.

9
Dry Chemical extinguishers
10
Dry Chemical extinguishers
  • Dry chemical extinguishers put out fires by
    coating the fuel with a thin layer of fire
    retardant powder, separating the fuel from the
    oxygen. The powder also works to interrupt the
    chemical reaction, which makes these
    extinguishers extremely effective.
  • Dry chemical extinguishers are usually rated for
    class B and C fires and may be marked multiple
    purpose for use in A, B, and C fires. They
    contain an extinguishing agent and use a
    compressed, non-flammable gas as a propellant.
  • Dry Chemical extinguishers will have a label
    indicating they may be used on class A, B, and/or
    C fires.

11
HCFC extinguishers
  • Ideal for all classes of fire (A,B,C)
  •              
  • Non-expirable. No need for yearly refill.
  • Non-corrosive.
  • Non-residual. Not messy to use.
  • Multi-shot. Can be used for several times.
  • Stop combustion chemically and directly without
    powder, foam or water.

12
How Fire Extinguishers Work?
Portable fire extinguishers apply an
extinguishing agent that will either cool burning
fuel, displace or remove oxygen, or stop the
chemical reaction so a fire cannot continue to
burn. When the handle of an extinguisher is
compressed, it opens an inner canister of
high-pressure gas that forces the extinguishing
agent from the main cylinder through a siphon
tube and out the nozzle.
13
Care and Maintenance of Your
Extinguisher At least once a month you should
inspect your extinguisher. Ensure that
  • The extinguisher is not blocked by objects that
    could interfere with access in an emergency.
  • The labels are readable.
  • The pressure is at the recommended level.
  • The nozzle or other parts are not obstructed.
  • The pin and tamper seal (if it has one) are
    intact.
  • There are no dents, leaks, rust, chemical
    deposits and other signs of abuse/wear.
  • Some manufacturers recommend shaking your dry
    chemical extinguishers to prevent the powder from
    settling/packing.
  • Fire extinguishers should be pressure tested (a
    process called hydrostatic testing) after a
    number of years to ensure that the cylinder is
    safe to use.

If the extinguisher is damaged or needs
recharging, get it replaced immediately! Recharge
all extinguishers immediately after use
regardless of how much they were used.
14
Following the P.A.S.S Technique
  • Pull
  • Aim
  • Squeeze
  • Sweep

15
Following the P.A.S.S Technique
Pull Pull the pin. This will also break the
tamper seal.
If you have the slightest doubt about your
ability to fight a fireEVACUATE IMMEDIATELY!
16
Following the P.A.S.S Technique
Aim Aim low, pointing the extinguisher nozzle
(or its horn or hoses) at the base of the fire.
If you have the slightest doubt about your
ability to fight a fireEVACUATE IMMEDIATELY!
17
Following the P.A.S.S Technique
Squeeze Squeeze the handle so that it will
release the extinguishing agent.
If you have the slightest doubt about your
ability to fight a fireEVACUATE IMMEDIATELY!
18
Following the P.A.S.S Technique
Sweep Sweep from side to side at the base of
the fire until the extinguisher is completely
empty assuring that the fire is out.
If you have the slightest doubt about your
ability to fight a fireEVACUATE IMMEDIATELY!
19
Fire extinguishers can represent an important
segment of any overall fire protection program.
However, their successful functioning depends
upon the following conditions having been met
  • (a) The fire extinguisher is properly located and
    in working order.
  • (b) The fire extinguisher is of the proper type
    for a fire that can occur.
  • (c) The fire is discovered while still small
    enough for the fire extinguisher to be effective.
  • (d) The fire is discovered by a person ready,
    willing, and able to use the fire extinguisher.

20
In The Event of Fire
F
ind
I
nform
R
eact
E
xtinguish
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