Intermediate
SFFMA Objectives: 24-02.01 – 24-02.11
8Hrs received
SFFMA Objectives
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24-02.01 Trainee shall identify the type, design, operation, nozzle pressure and flow in GPM of various types of
nozzles.
24-02.02 Trainee shall list the different types of fire streams.
24-02.03 Trainee, given a 2½ inch straight stream nozzle, shall demonstrate the proper opening and closing techniques
and line movement procedures.
24-02.04 Trainee shall calculate nozzle reaction for various nozzle pressures.
24-02.05 Trainee, given the proper information, shall list advantages and disadvantages of various nozzles:
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A. straight stream
B. fog
C. master stream
24-02.06 Trainee shall define water hammer and list ways of preventing water hammer.
24-02.07 Trainee shall calculate the water flow rate needed to control fire in a room that is 20'x20'x 8'.
24-02.08 Trainee, given a diagram of various nozzles, shall list major parts and trace flow routes through each.
24-02.09 Trainee shall list factors that influence fire steams.
24-02.10 Trainee shall list the proper procedures for inspection and maintenance of fire fighting nozzles.
24-02.11 Trainee shall demonstrate the operations of the pumper pressure relief system and/or pressure control valve as
follows:
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A. Trainee, given a pump panel, shall identify a pressure relief system.
B. Trainee shall list the reasons a pressure relief system is used.
C. Trainee shall list the different types of pressure relief systems used in the fire service.
D. Trainee shall list three (3) reasons of how excessive pressure develops in fire hose.
NOZZLE REACTION
 Counterforce directed against a person holding a
nozzle or a device holding a nozzle by the velocity of
water being discharged.
 Measured in pounds
 Nozzle reaction formulas NR= 1.57·d²·NP and NR=
0.0505·Q·NP
Fire Stream Classifications
 Low-volume stream
 Handline stream
 Master stream
Firefighter I
14–4
Fire Stream Considerations
 Volume discharged determined by design of nozzle,
pressure at nozzle
 To be effective, stream must deliver volume of water
sufficient to absorb heat faster than it is being
generated
(Continued)
Firefighter I
14–5
Fire Stream Considerations
 Type of fire stream indicates
specific pattern/shape of water
stream
 Requirements of effective
streams
 Requirements of all streams
Firefighter I
14–6
Solid Stream
 Produced from fixed
orifice, solid-bore
nozzle
 Has ability to reach
areas others might not; reach affected by several
factors
 Design capabilities
(Continued)
Firefighter I
14–7
Solid Stream
 Velocity of stream a result of nozzle pressure
 Nozzle pressure, size of discharge opening determine
flow
 Characteristics of effective fire streams
 Flow rate
Firefighter I
14–8
Advantages of Solid Streams
 May maintain better interior visibility than others
 May have greater reach than others
 Operate at reduced nozzle pressures per gallon (liter)
than others
 May be easier to maneuver
(Continued)
Firefighter I
14–9
Advantages of Solid Streams
 Have greater penetration power
 Less likely to disturb normal thermal layering of heat,
gases during interior structural attacks
 Less prone to clogging with debris
(Continued)
Firefighter I
14–10
Advantages of Solid Streams
 Produce less steam conversion than fog nozzles
 Can be used to apply compressed-air foam
Firefighter I
14–11
Disadvantages of Solid Streams
 Do not allow for different stream pattern selections
 Provide less heat absorption per gallon (liter) delivered
than others
 Hoselines more easily kinked at corners, obstructions
Firefighter I
14–12
DISCUSSION QUESTION
What type of fire situation would be ideal for a solidstream nozzle?
Firefighter I
14–13
Fog Stream
 Fine spray composed of tiny
water droplets
 Design of most fog nozzles
permits adjustment of tip to
produce different stream
patterns
(Continued)
Firefighter I
14–14
Fog Stream
 Water droplets formed to expose maximum water
surface for heat absorption
 Desired performance of fog stream nozzles judged by
amount of heat that fog stream absorbs and rate by
which the water is converted into steam/vapor
(Continued)
Firefighter I
14–15
Fog Stream
 Nozzles permit settings of straight stream, narrow-
angle fog, and wide-angle fog
 Nozzles should be operated at designed nozzle
pressure
(Continued)
Firefighter I
14–16
Fog Stream
 Several factors affect reach of fog stream
 Interaction of these factors on fog stream results in fire
stream with less reach than that of straight or solid
stream
(Continued)
Firefighter I
14–17
Fog Stream
 Shorter reach makes fog streams less useful for
outside, defensive fire fighting operations
 Well suited for fighting interior fires
Firefighter I
14–18
Fog Stream: Waterflow
Adjustment
 Two types of nozzles control rate of water flow
through fog nozzle
 Manually adjustable nozzles
 Automatic nozzles
Firefighter I
14–19
DISCUSSION QUESTION
How should adjustments to the rate of flow be made?
Firefighter I
14–20
Fog Stream: Nozzle Pressure
 Combination nozzles designed to operate at different
pressures
 Designated operating pressure for most combination
nozzles is 100 psi (700 kPa)
(Continued)
Firefighter I
14–21
Fog Stream: Nozzle Pressure
 Nozzles with other designated
operating pressures available
 Setbacks of nozzles with lower
operating pressures
Courtesy of Elkhart
Brass Manufacturing
Company.
Firefighter I
14–22
Advantages of Fog Streams
 Discharge pattern can be adjusted for situation
 Can aid ventilation
 Reduce heat by exposing maximum water surface for
heat absorption
 Wide fog pattern provides protection to firefighters
Firefighter I
14–23
DISCUSSION QUESTION
What type of fire situation would be ideal for a fogstream nozzle?
Firefighter I
14–24
Disadvantages of Fog Streams
 Do not have as much reach/penetrating power as solid
streams
 More affected by wind than solid streams
 May disturb thermal layering
 May push air into fire area, intensifying the fire
Firefighter I
14–25
Water Hammer
Water moving through a pipe or hose has both
weight and velocity. The weight of water increases
as the pipe or hose size increases. Suddenly
stopping water moving through a hose or pipe
results in an energy surge being transmitted in the
opposite direction, often at many times the original
pressure.
This surge is called Water Hammer
WATER HAMMER
 Force created by the rapid acceleration or deceleration
of water. It generally results from closing a valve or
nozzle too quickly.
 Can be up to seven (7) times the original pressure.
GAUGES
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Master Intake gauge (Compound)
Master Discharge gauge
Discharge gauge (individual gauges)
Oil Pressure
Voltmeter
Tachometer (engine RPM)
Pump overheat indicator
Engine coolant temperature gauge
Master Intake Gauge
 Measures positive or negative pressure
 Calibrated from 0 to 600 PSI (usually) for positive and
from 0 to 30 inches of vacuum for negative pressure
 Provides indication of residual pressure from a hydrant
or relay operation
 Provides indication of maximum capacity of pump
when at draft
Master Discharge Gauge
 Measures positive pressure
 Calibrated from 0 to 600 PSI
 Up to 1000 PSI on special pumpers
 Measures pressure as it leaves the pump and before it
gets to the individual gauges
 Always reads the highest pressure the pump is
producing
Discharge Gauge
 Individual gauges
measure the pressure for
each individual
discharge.
 Use these gauges not the
master discharge gauge
when flowing any line.
Oil Pressure Gauge
 Measures oil pressure of the
motor.
 Normal operating pressures
vary with different brands of
apparatus.
 Variations from normal may
indicate pending problems.
 Provides a relative indication of battery condition and
Voltmeter
alternator output by measuring the drop in voltage as
some of the more demanding electrical accessories are
used.
 Indicates the top voltage available when the battery is
fully charged.
 Measures drop when electrical demand is high.
Tachometer
 Records the engine speed in revolutions per minute
(rpm)
 It can give valuable information about the condition
of the pump.
 May refer to the acceptance test rating panel to check
on pump efficiency (identification plate on the pump
panel)
Pump Overheat Indicator
 Audible or visual indicator
 * Overheating occurs when the pump impeller is
spinning, for prolonged periods, but no water is being
discharged
Pump Overheat
 Best place to check for
overheat is right here
 Best way to never
overheat the pump is
to always be moving
water.
Engine Coolant
 Engine coolant temperature gauge
 Shows the temperature of the engine coolant - the
normal operating range of the Detroit Diesel Series 60
Engine is between 192° - 205° Fahrenheit
 Caution: An engine that operates too cool is not
efficient. An engine that has an operating temperature
that is too high may be damaged.
Cavitation
 Firefighters definition:
 Water is discharged from the pump faster than it is
coming in.
 Cavitation:
 A condition in which vacuum pockets form in the pump
and causes vibrations, loss of efficiency, and possible
damage.
Cavitation
 During Cavitation:
 The pressure at the eye of the impeller falls below
normal atmospheric pressure.
 The water boils faster at temperatures less than
normal atmospheric pressure.
 Steam and air bubbles are created.
 The air bubbles move outward in the impeller and
into the high-pressure zone.
 The air bubbles collapse, producing noise and
vibration.
Cavitation
 To Avoid Cavitation:
 Intake pressure from pressurized sources should not
drop below 20 psi.
 Cavitation can be recognized by the fact that increasing
the engine rpm does not result in an increase in
discharge pressure.
PRESSURE RELIEF SYSTEMS
Intake Pressure Relief Valves
Pressure Relief Valves
Pressure Governors
Intake Pressure Relief Valves
 Piston intake relief valves decrease the potential for a
water hammer.
 Two types of pressure relief devices:
 Piston intake relief valve
 Dump valve (on pump)
 Should be preset @ 100 PSI
 Can be set from 50 to 175 PSI
Intake relief valves-dump valves
 Relieves pressure from incoming supply lines, before it
goes into the pump.
Pressure Relief Valves
Waterous PRV
Hale PRV
Pressure Relief Valves
 Pressure relief valves must be set while
pumping the desired pressure with
water flowing.
 Must be set at highest pressure
necessary (gate back other lines).
 Pressure relief valves do not provide
cavitation protection.
Pressure Relief Valves
 They prevent an excessive amount of
pressure being transferred to another
line.
 Engine rpm will not fluctuate as lines are
opened or closed.
 Pressure Relief Valves divert water
internally.
Relief Valve Operation
Manual Throttle
 Operated via a cable to the
fuel system.
 CCW to increase and CW to
decrease speed.
 Red button in center is the
Emergency Shut-Down.
Pressure Governors
 Pressure governors regulate engine pressure
by adjusting engine rpm to compensate for
attack lines being opened or shut.
 This prevents an excessive amount of
pressure being transferred to another line.
 Engine rpm will fluctuate as lines are
opened or closed.
Pressure
Governors
 Pressure governors
must be set while
pumping the desired pressure.
 Must be set at highest pressure
necessary (gate back other lines)
 Pressure governors provide cavitation
protection.
 If the pressure governor senses an increase
in rpm without a corresponding increase
in pressure, the engine will return to idle
after 3-5 seconds.
Electronic Pressure Governor
 Seagraves version
Electronic Pressure Governor
 Quality version
Electronic Pressure Governor
 Detroit Diesel Fire
commander
 On all E-One Fire
Apparatus
Practical Exercise
 Firefighter shall:
 Identify the type, design, operation, nozzle pressure and
flow in GPM of various types of nozzles
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Fog
Straight Stream
Master Stream
 Firefighter shall:
 Given a 2 ½’’ straight stream nozzle, shall demonstrate
the proper opening and closing and line movement
procedures