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1
Chapter 11 Nozzles and Fire Streams
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IntroductionFires usually extinguished by water
Water delivered using nozzles and fire streams
Nozzle selection important
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Definition of Fire StreamFire streamFour elements affect stream:
PumpWaterHoseNozzle
Proper streamSufficient volumePressureDirection to reach its target
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NozzlesNozzles:
Solid stream and fogCombination nozzles:
Straight stream or adjustable spray Nozzle pressureNozzle flowNozzle reachStream shapeNozzle reaction
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Nozzles showing the stream shape for straight, solid, and wide pattern
streams.
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Solid Tip or StreamDeliver unbroken stream of waterSolid stream nozzle Flow a factor of tip size at a certain
nozzle pressureMinimal effect of room’s thermal
balanceDisadvantages:
Lack of volume controlLack of fog protectionHigher nozzle reaction
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Fog Nozzles
Deliver fixed or variable spray pattern
Fog provides better heat absorptionHydraulic ventilation
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Variable combination fog nozzle patterns. From top to bottom: straight stream, narrow
fog, and wide fog.
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Parts of a fog nozzle.
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Straight StreamCreates a hollow type streamMust pass around the baffle of the
nozzleCreates an opening in the patternMay allow air into the stream and reduce
its reachNewer designs have hollow effect
from the tip.
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Comparison of (A) straight and (B) solid streams at tip.
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Special PurposeNot often usedCellar nozzles and Bresnan
distributorsPiercing nozzles
Modified to pierce through building walls and floors
Water curtain nozzleSprays water to protect against heat
exposure
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(A) Cellar nozzle and (B) Bresnan distributor.
(A) (B)
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Piercing nozzle. Water curtain nozzle.
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Nozzle OperationsSolid tip nozzles easy to operate
Nozzle size and tip selectionFog nozzles with rotating valves
Gallonage and pattern adjustmentsFog nozzles have more applications
than smooth bore nozzles.Review Chapter 10.Most hoselines operated from
crouching or kneeling position
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Small-Diameter HandlinesTypically 38, 45, or 50 mm (1½, 1¾,
or 2 inches) in diameter Flow from 400 to over 1,000 L/min
(100 to over 250 gpm)When flowing at lower volumes,
operated by one personFog and solid tip nozzles can be used
for small lines.Ease of mobilityNumber of personnelExtinguishing ability
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Medium-Diameter Handlines
65 to 77 mm (2½-inch or 3-inch hose) Solid tip and fog nozzlesFlow from 625 to 1,200 L/min (165
to 325 gpm )65 mm (2½-inch) hose is standard
size hoselineLarge commercial structures
Require two or more personnel to operate
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Master Stream DevicesCapable of 1,400 L/min(350 gpm)Artillery of fire serviceLarge volumes of water Apparatus-mounted or secured
properlyOne person to operate
Lack of mobility
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Stream Application, Hydraulics, and Adverse Conditions
Applications of fire streams vary Method of fire attackConditions encountered Including environmental factorsWater supply
Proper pressure and flowHydraulics
Improper hydraulic calculations are the leading cause of poor fire streams
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Direct, Indirect, andCombination Attack
Direct fire attackIndirect fire attackCombination attack
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Firefighter directly attacking a fire.
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Firefighter using indirect attack by applying water into room and then closing the door.
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Basic Hydraulics, Friction Loss, and Pressure Losses in Hoselines
HydraulicsPressureFlowMoving water through hoselines,
nozzles and appliances requires forces that act positively and negatively to achieve flow.MassPressure
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Friction LossThe loss of energy from the
turbulence, or rubbing, of the moving water through the hose
Pump operator compensates for friction loss by increasing the pump pressure for the correct pressure to the nozzle.
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Friction Loss PrinciplesFriction loss is based on four principles:Friction loss varies directly with the length of
the hose if all other variables are held constant.Friction loss varies approximately with the
square of the flow.When the flow remains constant, friction loss
varies inversely with the hose diameter.For any given velocity, the friction loss will be
about the same regardless of the water pressure.
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Pump Discharge PressureDischarge pressure of a pump: PDP
= NP + FL ± E + APump Discharge PressureNozzle PressureFriction LossElevation Appliance loss
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Example for friction loss and pump discharge pressure calculations.
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Adverse ConditionsTwo types: natural and man-madeNatural
Wind and wind directionRain, snow, hail, tree branches, wires Gravity and air friction
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Lessons LearnedFire streams
Solid tip and fog nozzlesNozzle should match fire conditions and
department resourcesCorrect hydraulics calculationsEffective use of nozzles and fire
streams on the fireground