Transcript Chapter 11
Nozzles and Fire Streams
1
Introduction
Fires usually extinguished by water
Water delivered using nozzles and fire
streams
Nozzle selection important
2
Definition of Fire Stream
Fire stream
Four elements affect stream:
Pump
Water
Hose
Nozzle
Proper stream
Sufficient volume
Pressure
Direction to reach its target
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Nozzles
Nozzles:
Solid stream and fog
Combination nozzles:
Straight stream or adjustable spray
Nozzle pressure
Nozzle flow
Nozzle reach
Stream shape
Nozzle reaction
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Nozzles showing the stream shape for straight,
solid, and wide pattern streams.
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Solid Tip or Stream
Deliver unbroken stream of water
Solid stream nozzle
Flow a factor of tip size at a certain nozzle
pressure
Minimal effect of room’s thermal balance
Disadvantages:
Lack of volume control
Lack of fog protection
Higher nozzle reaction
6
Fog Nozzles
Deliver fixed or variable spray pattern
Fog provides better heat absorption
Hydraulic ventilation
7
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 Stream
Creates a hollow type stream
Must pass around the baffle of the nozzle
Creates an opening in the pattern
May allow air into the stream and reduce its reach
Newer 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 Purpose
Not often used
Cellar nozzles and Bresnan distributors
Piercing nozzles
Modified to pierce through building walls and
floors
Water curtain nozzle
Sprays water to protect against heat exposure
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(A)
(B)
(A) Cellar nozzle and (B) Bresnan distributor.
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Piercing nozzle.
Water curtain nozzle.
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Nozzle Operations
Solid tip nozzles easy to operate
Nozzle size and tip selection
Fog nozzles with rotating valves
Gallonage and pattern adjustments
Fog 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 Handlines
Typically 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 person
Fog and solid tip nozzles can be used for
small lines.
Ease of mobility
Number of personnel
Extinguishing ability
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Medium-Diameter
Handlines
65 to 77 mm (2½-inch or 3-inch hose)
Solid tip and fog nozzles
Flow from 625 to 1,200 L/min (165 to 325
gpm )
65 mm (2½-inch) hose is standard size
hoseline
Large commercial structures
Require two or more personnel to
operate
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Master Stream Devices
Capable of 1,400 L/min(350 gpm)
Artillery of fire service
Large volumes of water
Apparatus-mounted or secured properly
One person to operate
Lack of mobility
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Stream Application, Hydraulics, and
Adverse Conditions
Applications of fire streams vary
Method of fire attack
Conditions encountered
Including environmental factors
Water supply
Proper pressure and flow
Hydraulics
Improper hydraulic calculations are the leading
cause of poor fire streams
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Direct, Indirect, and
Combination Attack
Direct fire attack
Indirect fire attack
Combination attack
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Firefighter directly attacking a fire.
21
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
Hydraulics
Pressure
Flow
Moving water through hoselines,
nozzles and appliances requires forces
that act positively and negatively to
achieve flow.
Mass
Pressure
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Friction Loss
The 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
Principles
Friction 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 Pressure
Discharge pressure of a pump: PDP = NP +
FL ± E + A
Pump Discharge Pressure
Nozzle Pressure
Friction Loss
Elevation
Appliance loss
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Example for friction loss and pump discharge pressure calculations.
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Adverse Conditions
Two types: natural and man-made
Natural
Wind and wind direction
Rain, snow, hail, tree branches, wires
Gravity and air friction
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Lessons Learned
Fire streams
Solid tip and fog nozzles
Nozzle should match fire conditions and department
resources
Correct hydraulics calculations
Effective use of nozzles and fire streams on the
fireground
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