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Fire Streams

Fire Streams. Geronimo Vol. Fire Dept. Extinguishing Properties of Water. Water extinguishes fires by Cooling Remove heat from the fire Smothering Absorb large quantities of heat Dilute oxygen. Heat Absorption.

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Fire Streams

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  1. Fire Streams Geronimo Vol. Fire Dept.

  2. Extinguishing Properties of Water • Water extinguishes fires by • Cooling • Remove heat from the fire • Smothering • Absorb large quantities of heat • Dilute oxygen

  3. Heat Absorption • Small particles absorb heat and converts into steam more rapidly than a compact form • Example - same cubes of ice melt faster then large cube of ice • Fog stream verse straight stream

  4. Water’s Expansion Capability • At 212 F water expands approximately 1,700 times its original volume when converted to stream • Example - If a nozzle discharges 150 gallons a minute, 20 cubic feet of water will be created. At 500 F that will convert into 48,000 cubic feet of steam. This will fill a room 50 feet wide by 96 feet long

  5. Water’s Expansion Capability • Steam will displace smoke and gases and mess up the thermal balance. • Insure that adequate ventilation is available • If ventilation is adequate • Fire will be extinguished or reduced in size • Visibility may be maintained • Room temperature is reduced

  6. Important Characteristics of Water • Readily available and inexpensive • Water has a greater heat-absorbing capacity than other common extinguishing agents • Water changing into steam requires a relatively large amount of heat • The greater the surface area of the water exposed, the more rapidly heat is absorbed

  7. Pressure Loss/Gain • Pressure Loss and Gain are effected by • Friction loss • Elevation • Friction loss is caused by • Hoses (length and diameter) • Nozzles • Adapters • Elevation • If nozzle is above the pump pressure is lost • If nozzle is below the pump pressure is gained

  8. Water Hammer • Water hammer is the sudden stoppage of water through fire hose or pipe • This can damage water mains, plumbing, fire hose, hydrants, valves, and hose clamps • Close valves and nozzles slowly to prevent water hammers

  9. Water Fire Stream Patterns and Nozzles • Low-volume streams • Less then 40 gpm (booster hoselines) • Handline streams • 40 to 350 gpm (1 1/2 to 3 in hose) • Master streams • 350 gpm + (multiple 2 1/2 or 3 in hoses)

  10. Water Fire Stream Patterns and Nozzles • Solid Stream • Produced from a fixed orifice, smoothbore nozzle • Long reach • Penetration • 50 psi at the nozzle for handlines • 80 psi at the nozzle for master streams • No foam

  11. Water Fire Stream Patterns and Nozzles • Fog Stream • Composed of very fine water droplets • Settings • Straight streams • Narrow-angle fog (15 to 45) • Wide-angle fog (45 to 80) • Operate at the set nozzle pressure • Used mainly for interior attacks

  12. Factors That Affect Reach • Gravity • Water velocity • Fire stream pattern selection • Water droplet friction with air • Wind

  13. Fog Nozzles • Manually adjustable nozzles • You set the gpm on the nozzle • Automatic nozzles • Pressure from the pump determines the gpm

  14. Fog Nozzle Advantages • Dissipate more heat then solid stream nozzles due to greater water surface area • Aids in ventilation • Adjustable pattern

  15. Maintenance of Nozzles • Check the swivel gasket for damage or wear • Look for external damage • Look for internal damage and debris • Check for ease of operation by physically operating the nozzle parts • Check to make sure that the pistol grip is secure

  16. Foam • Foam extinguishes and/or prevents fire by • Separating • Creates a barrier between the fuel and the fire • Cooling • Lowers the temp. of the fuel and adjacent surfaces • Suppressing • Prevents the release of flammable vapors and therefore reduces the possibility of ignition or reignition

  17. Class A Foam • Used on ordinary combustibles • Wildland and structure fires • May be proportioned as needed • From a dry (thick) foam to a wet (thin) foam

  18. Class B Foam • Used to help extinguish hydrocarbon fuel fires • Oil, fuel oil, gasoline, benzene, naphtha, jet fuel, and kerosene • Floats on top of the fuel • Traps vapors in • Keeps oxygen out • Proportion is per manufacturer’s recommendations • Normally 3 to 6 percent

  19. Proportioning • Four methods • Induction • Injection • Batch-mixing • Premixing

  20. Foam Application Techniques • Roll-On Method • Stray foam at the front edge of the burning fuel • Bank-Down Method • Stray foam on an elevated object in the fuel • Rain-Down Method • Stray foam in the air above the fuel and let it rain down

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