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Water as an Extinguishing Agent

The great majority of fires are extinguished

using water.

Water is usually available at or near the fire

scene and has special physical properties well

suited for fire fighting.

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Extinguishing Properties of Water

Coolingdepends on how quickly water is applied,

how much is applied and what form.

Water absorbs the most heat when it is converted tosteam and that is more easily performed from droplets.

Smotheringfoaming agent is usually added to the

water.

EmulsificationCools surface of flammable liquids

and prevents release of flammable vapors.

Dilutionfor fires in water-soluble flammable

materials.

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Electrical Conductivity of Water

Water in its natural state contains impurities

that make it conductive.

If water is applied to fires involving electricity,

continuous circuit may be formed and shock

applier.

Water-based foam agents are very conductive.

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Using Water on Special Hazards

Chemicals

Combustible Metals

Radioactive Materials

Gases

Combustible & Flammable Liquids

Cooling agent

Mechanical tool

Displacing medium

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Increased Friction Loss

Sediment and Debris Incrustation from Mineral Deposits

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Hydrant Inspection & Maintenance

Obstructions preventing

pumper-to-hydrant

connections

Outlets facing properdirection for pumper-to-

hydrant connections

Sufficient clearance

between the outlets andground for hose

connections

Damage

Rust or corrosion

Hydrant caps stuck in place

with paint

Operable operating stem

(easily turned)

Obstructions (bottles, cans,

rocks) inside hydrant

restricting water flow

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Sprinkler System Design & Operation

Series of sprinklers arranged to automaticallydistribute enough water to extinguish or check fire.

Water is supplied to sprinklers through a pipingsystem.

Systems sprinkler heads discharge water after a capor plug is released by a heat-responsive element.

NFPA 13 Standard for the Installation of SprinklerSystems, but other NFPA standards also have adirect bearing on certain phases of sprinklerprotection.

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Sprinkler System Advantages

Most reliable

Most effective

(control 96% of fires in sprinkler-protectedbuildings)

Less business interruption

Less water damage

Enhance life safety

Reduce insurance costs

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Parts of a Sprinkler Head

Frame

Arms

Lever

Arms

Valve

Cap

Deflector

Release

Mechanism

(Fusible Link)

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Releasing Mechanisms

Fusible Link

(Standard)

Chemical

Pellet

Frangible

Bulb

Fusible Link

(QuickResponse)

Sprinkler Head Activation

http://www.youtube.com/watch?v=g7DPETydztQ&feature=relatedhttp://www.youtube.com/watch?v=g7DPETydztQ&feature=related

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How the Bulb Works

1. Heat from fire

heats liquid in

bulb & breaks.

2. Releases cap.

3. Water is released

onto diffuser.4. Water puts out

fire.

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Sprinkler Head Temp Ratings

Sprinkler heads are designed with

temperature ratings ranging from 135oF to as

high as 500oF.

Ratings of 165oF are common for use in

buildings maintained at normal, constant

temperatures.

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Sprinkler Bulb Colors

Temperature Rating

(oF)

Temperature

Classification

Glass Bulb Color

135-170 Ordinary Orange or red

175-225 Intermediate Yellow or green

250-300 High Blue

325-375 Extra High Purple

400-475 Very Extra High Black

500-575+ Ultra High Black

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Sprinkler Head Designs

Pendant

Sidewall

Upright

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Wet Pipe Sprinkler System

Uses a piping system containing water underpressure at all times.

When a fire occurs, individual sprinklers areactivated by heat, and water flows throughthose sprinklers immediately.

Generally used wherever there is no dangerof the water in the pipes freezing and nospecial conditions requiring one of the othersystems.

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Wet Pipe Sprinkler System

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Dry Pipe Sprinkler System

Sprinklers attached to piping which contains airor nitrogen under pressure.

When a sprinkler is opened by heat, thepressure is reduced to the point where waterpressure on the supply side can force open the

valve. Then water flows into the system and out any

opened sprinklers.

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Preaction System

Contain air in the piping that may or may notbe under pressure.

When a fire occur, a supplementary firedetecting device in the area is activated.

This opens a water control valve which permitswater to flow into the piping system before a

sprinkler is activated. When sprinklers are opened by heat of the fire,

water flows through the sprinklers immediately

same as a wet pipe system.

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Situations In Which

Sprinklers Are Effective

Preventing fire spread upwards in multiple-

story buildings.

Protecting the lives of occupants in other

parts of the building.

Sprinkler Demonstration Video

Start at 3:00

http://www.youtube.com/watch?v=wwfEawAXqnMhttp://www.youtube.com/watch?v=wwfEawAXqnM

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Situations In Which Sprinklers May Not

Be Effective

Fires too small to activate sprinkler system.

Smoke reaches occupants before sprinklersystem activates.

Sleeping, intoxicated, or handicapped

persons occupy fire building.

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