Pumping Apparatus Driver/Operator
Lesson 10 -
Fire Pump Theory
Contents
[Click on underlined word(s) to go to any of the areas below]
Planning Page
Objectives
Lesson Outline
Lesson Quiz
Lesson Quiz Answers
Written Test
Written Test Answers
Competency Profile
Pumping Apparatus Driver/Operator -
Lesson 10
Pumping Apparatus Driver/Operator
Lesson 10 -
Fire Pump Theory
Planning Page
PREPARATION
Lesson Overview
This lesson provides the driver/operator with the basic concepts regarding the various types of fire
pumps and their operation. Also included is information on the various components that make up the
overall apparatus pumping sytem.
Assignment Sheets/SkiJI Sheets
This lesson does not have any corresponding assignment or skill sheets.
Equipment and Materials
Computer
Data Projector/screen
Audiovisual Aids
Lesson 10 PowerPoint® Presentation
Evaluation
Lesson 10 Quiz
Lesson 10 Written Test
REFERENCES
Pumping Apparatus Driver/Operator Handbook, 2nd Ed., Stillwater, Oklahoma: Fire Protection
Publications, 2006.
NFPA 1002 Standardfor Fire Apparatus Driver/Operator Professional Qualifications, Quincy,
Massachusetts: National Fire Protection Association, 2003.
Pumping Apparatus Driver/Operator -
Lesson I 0
2
Pumping Apparatus Driver/Operator
Lesson 10 -
Fire Pump Theory
Objectives
Course
After completing this course, the student will be able to certify as a Pumping Apparatus
Driver/Operator per the following:
•
Lesson
NFPA f002 Standardfor Fire Apparatus Driver/Operator Professional
Qualifications, 2003 Edition
After completing this lesson, the student will achieve an acceptable score, as defined by
the student's training organization, on the Written Test.
Specific After completing this lesson, students will be able to -
1. Select facts about positive displacement pumps.
2. Complete statements about the operation of positive displacement fire pumps.
3. Answer questions about centrifugal pumps.
4. Complete statements about the operation of centrifugal pumps.
5. Match centrifugal pumps to their characteristics.
6. Answer questions about changeover.
7. Select facts about pump wear rings and packing rings.
8. Identify characteristics of pump mounting and drive arrangements.
9. Answer questions about intake and discharge piping.
10. Select facts about valves.
II. Distinguish between types of valve actuators.
12. List purposes of drain valves and bleeder lines.
13. Identify characteristics of various automatic pressure control devices.
14. Match pump primers to their descriptions and operating techniques.
15. Match pump panel controls and instruments to their descriptions.
16. State the primary function of an auxiliary cooler.
17. Explain the operation of marine- and immersion-type auxiliary coolers.
Pumping Apparatus Driver/Operator -
Lesson 10
3
Pumping Apparatus Driver/Operator
Lesson 10 -
Fire Pump Theory
Lesson Outline
INTRODUCTION/MOTIVATION
Discuss the history of fire pumps used in the fire service, including hand operated pumps and
rotary pumps.
Review
the specific objectives you plan on teaching.
PRESENTATION OUTLINE
VISUALS/NOTES
Objective 1 - Select facts about positive displacement
pumps.
Objective 2 - Complete statements about the
operation of positive displacement fire pumps.
A. Have been largely replaced by the centrifugal pump for use as
the main fire pump on modem fire apparatus
Slide 10-6
Positive Displacement Pumps
B. Are still a necessary part ofthe overall pumping system on
modem fire apparatus because they can pump air
C. Are used as priming devices to get water into centrifugal
pumps during drafting operations; by removing the air trapped
in the centrifugal pump, water is forced into the pump casing
by atmospheric pressure
Slide 10-7
Positive Displacement Pumps
D. Are of two basic types
I. Piston
2. Rotary
E. Piston pumps
I. Operation
a. Piston pumps contain a piston that moves back and
forth inside a cylinder. The pressure developed by this
action causes intake and discharge valves to operate
automatically and provides for the movement of the
water through the pump.
b. As the piston is driven forward, the air within the
cylinder is compressed, creating a higher pressure
Pumping Apparatus Driver/Operator -
Slide 10-8
Operation of Piston Pumps
Slides 10-9 -10-10
Operation of Piston Pumps
Lesson 10
4
2.
3.
4.
5.
6.
inside the pump than the atmospheric pressure in the
discharge manifold. This pressure causes the discharge
valve to open and the air to escape through the
discharge lines.
c. This action continues until the piston completes its
travel on the forward stroke and stops. At that point,
pressures equalize and the discharge valve closes.
d. As the piston begins the return stroke, the area within
the cylinder behind the piston increases and the
pressure decreases, creating a partial vacuum. At this
time, the intake valve opens, allowing some of the air
from the suction hose to enter the pump.
e. As the air from the suction hose is evacuated and
enters the cylinder, the pressure within the hose and
the intake area of the pump is reduced. Atmospheric
pressure forces the water to rise within the hose until
the piston completes its travel and the intake valve
closes.
f. As the forward stroke is repeated, the air is again
forced out of the discharge. On the return stroke, more
ofthe air in the intake section is removed and the
column of water in the suction hose is raised. This
action is repeated until all the air has been removed
and the intake stroke results in water being introduced
into the cylinder. The pump is now considered to be
primed, and further strokes cause water to be forced
into the discharge instead of air.
Single-acting piston pump
a. Works when the forward stroke causes water to be
discharged, and the return stroke causes the pump to
fill with water again
b. Does not produce a usable fue stream because the
discharge would be a series of surges of water
followed by an equal length of time with no water
Double-acting piston pump
a. Has two additional valves to produce a more constant
stream
b. Receives and discharges water on each stroke of the
piston
The output capacity is determined by the size of the
cylinder and the speed of the piston travel.
There is a practical limit to the speed that a pump can be
operated, so the capacity is usually determined by the size
of the cylinder.
Multicylinder pumps
a. Are more practical to build than one large single-
I
Slide 10-11
Operation of Piston Pumps
Slides 10-12 - 10-13
Operation of Piston Pumps
Slide 10-14
Operation of Piston Pumps
Slides 10-15 -10-16
Operation of Piston Pumps
Slide 10-17
Single-Acting Piston Pump
Slide 10-18
Double-Acting Piston Pump
Slide 10-19
Piston Pump Characteristics
Slide 10-21
Multicylinder Pumps
Pumping Apparatus Driver/Operator - Lesson 10
5
cylinder pump
b. Are more flexible and efficient because some
cylinders can be disengaged when the pump's full
capacity is not needed
c. Provide a more uniform discharge
7. Have not been used as the major fire pump in pumpers for
many years
8. Are still in service for high-pressure stream fire fighting
Slide 10-20
Piston Pump Characteristics
F. Rotary pumps
I. Are the simplest of all fire apparatus pumps in design
2. Were used extensively as the major pump on older fire
apparatus
3. Are now used as small capacity booster-type pumps, lowvolume high pressure pumps, and priming pumps
4. Rotary gear pumps
a. The rotary gear pump consists of two gears that rotate
in a tightly meshed pattern inside a watertight case.
The gears are constructed so that they contact each
other and are in close proximity to the case.
b. With this arrangement, the gears within the case form
watertight and airtight pockets as they turn from the
intake to the outlet.
c. As each gear tooth reaches the discharge chamber, the
air or water contained in that pocket is forced out of
the pump.
d. As the tooth returns to the intake side ofthe pump, the
gears are meshed tightly enough to prevent the water
or air that has been discharged from returning to the
intake.
e. Produce amount of water dependent upon the size of
the pockets in the gears and the speed of rotation
f. Are very susceptible to damage from normal wear,
sand, and other debris; can be prevented with bronze
or soft metal gears
5. Rotary vane pumps
a. Are constructed with movable elements that
automatically compensate for wear and maintain a
tighter fit with closer clearances as the pump is used
b. Are one of the most common types of pumps used to
prime centrifugal pumps
c. The rotor is mounted off-center inside the housing.
The distance between the rotor and the housing is
much greater at the intake than it is at the discharge.
The vanes are free to move within the slot where they
Pumping Apparatus Driver/Operator - Lesson 10
Slide 10-22
Rotary Pumps
Slide 10-23
Operation of Rotary
Gear Pumps
Slide 10-24
Operation of Rotary
Gear Pumps
Slide 10-25
Operation of Rotary
Gear Pumps
Slide 10-26
Rotary Gear Pump
Characteristics
Slide 10-27
Rotary Vane Pump
Characteristics
Slide 10-28
Rotary Vane Pump
Characteristics
Slide 10-29
Operation of Rotary
Vane Pumps
6
are mounted.
d. As the rotor turns, the vanes are forced against the
housing by centrifugal force.
e. When the surface of the vane that is in contact with the
casing becomes worn, centrifugal force causes it to
extend further, thus automatically maintaining a tight
fit.
f. As the rotor turns, air is trapped between the rotor and
the casing in the pockets formed by adjacent vanes.
g. As the vanes turn, this pocket becomes smaller, which
compresses the air and causes pressure to build up.
This pocket becomes even smaller as the vanes
progress toward the discharge opening.
h. At this point, the pressure reaches its maximum level,
forcing the trapped air out of the pump. The air or
water is prevented from returning to the intake by the
close spacing of the rotor at that point.
1.
As in the rotary gear pump, the air being evacuated
from the intake side causes a reduced pressure (similar
to a vacuum), and water is forced into the pump by
atmospheric pressure until the pump fills with water.
J. At this point, the pump is primed and forces water out
of the discharge in the same manner as air was forced
out.
k. Are more efficient at pumping air than a standard
rotary gear pump because the pump is self-adjusting
Slide 10-30
Operation of Rotary
Vane Pumps
Slide] 0-31
Operation of Rotary
Vane Pumps
Slide 10-32
Operation of Rotary
Vane Pumps
Slide 10-33
Operation of Rotary
Vane Pumps
Objective 3 - Answer questions about centrifugal
pumps.
Objective 4 - Complete statements about the
operation of centrifugal pumps.
Slide 10-34
Centrifugal Pumps
A. Centrifugal pumps are utilized by nearly all modem fire
apparatus.
B. The centrifugal pump is classified as a nonpositive
displacement pump because it does not pump a definite
amount of water with each revolution. Rather, it imparts
velocity to the water and converts it to pressure within the
pump itself. This gives the pump a flexibility and versatility
that has made it popular with the fire service.
C. The centrifugal pump has virtually eliminated the positive
displacement pump as a major fire pump in the fire apparatus.
Pumping Apparatus Driver/Operator -
Lesson 10
Slide 10-35
Centrifugal Pumps
7
D. The centrifugal pump consists of:
I. Impeller - Transmits energy in the form of velocity to
the water
2. Casing - Collects the water and confines it in order to
convert thc velocity to pressure
3. Volute - Is a water passage that gradually increases in
cross-sectional area as it nears the pump discharge outlet
Slides 10-36 - 10-37
Centrifugal Pumps
E. The impeller in a centrifugal pump rotates very rapidly within
the casing, generally from 2,000 to 4,000 rpm.
Slide 10-38
Centrifugal Pumps
F. The volume capacity of the pump is dependent on the size of
the eye of the impeller. The greater the eye, the greater the
flow capacity.
G. The three main factors that influence a centrifugal fire pump's
discharge pressure:
1. Amount of water being discharged
2. Speed at which the impeller is turning
3. Pressure of water when it enters the pump from a
pressurized source (hydrant, relay, etc.)
Slide 10-39
Centrifugal Pumps
Slides 10-40 - 10-41
H. Principles of operation and construction
Operation and Construction
I. The operation of a centrifugal pump is based on the
Centrifugal Pumps
principle that a rapidly revolving disk tends to throw water
introduced at its center toward the outer edge of the disk.
The faster the disk is turned, the farther the water is
thrown, or the more velocity the water has.
Slide 10-42
2. If the water is contained at the edge of the disk, the water
Operation and Construction
at the center of the container begins to move outward. The
Centrifugal Pumps
velocity created by the spinning disk is converted to
pressure by confining the water within the container.
3. The water is limited in its movement by the walls of the
container and moves upward in the path of least
resistance.
Slide 10-43
4. This shows that pressure has been created on the water.
Operation and Construction
The height to which it rises, or the extent to which it
Centrifugal Pumps
overcomes the force of gravity, depends upon the speed of
rotation.
Slide 10-44
S. The centrifugal pump consists of two parts: an impeller
and a casing. The impeller transmits energy in the form of Operation and Construction
Centrifugal Pumps
velocity to the water. The casing collects the water and
confines it in order to convert the velocity to pressure.
Then the casing directs the water to the discharge of the
pump.
Pumping Apparatus Driver/Operator - Lesson 10
of
of
of
of
8
Objective 5 - Match centrifugal pumps to their
characteristics.
A. Single-stage centrifugal fire pumps
I. Are constructed with a single impeller
2. Are used on front-mount pumps, PTOs, separate enginedriven and midship transfer pumps
3. May provide capacities up to 2,000 gpm (8 000 Llmin)
4. May have a double suction impeller to minimize the
lateral thrust oflarge quantities of water entering the eye
of the impeller
B. Multi-stage centrifugal fire pumps
I. Have an impeller for each stage mounted within a single
housing
2. Have impellers that are usually mounted on a single shaft
driven by a single drivetrain
3. Have identical impellers that are the same capacity
4. Have the capability of connecting the stages in series for
maximum pressure or in parallel for maximum volume by
use of a transfer valve
Slides 10-45 - 10-46
Single-Stage Centrifugal
Fire Pumps
Slides 10-47 -10-48
Multi-Stage Centrifugal
Fire Pumps
C. Multi-stage pumps in the parallel (volume) position
I. Have impellers that take water from a source and deliver it
to the discharge
2. Cause impellers to be capable of delivering their rated
pressure while flowing 50 percent of the rated capacity;
therefore, the total amount of water the pump can deliver
is equal to the sum of each stage
Example: If a two-stage pump is rated at 1,000 gpm (4
000 Llmin) at ISO psi (1 000 kPa), each of the impellers
supplies 500 gpm (2 000 Llmin) to the pump discharge
manifold. There the two streams combine, so the total
amount available to the discharges is 1,000 gpm (4 000
Llmin) at a net pump pressure of ISO psi (I 000 kPa).
Slides 10-49 -10-50
Multi-Stage Pumps in the
Parallel (Volume) Position
D. Multi-stage pumps in the series (pressure) position
I. Work by all water from the manifold being directed into
the eye of the first impeller, increasing the pressure and
discharging 50 to 70 percent ofthe volume capacity
through the transfer valve and into the eye of the second
impeller
2. Have a second impeller that increases the pressure and
delivers the water at the higher pressure into the pump
Slides 10-51 -10-52
Multi-Stage Pumps in the
Series (Pressure) Position
Pumping Apparatus Driver/Operator -
Lesson 10
9
discharge port.
Objective 6 -
Answer questions about changeover.
A. Changeover is the process of switching between the pressure
and volume position.
Slide 10-53
Changeover
B. SOPs in some departments specify that the transfer valve stay
in the pressure position until it is necessary to supply more
than one-half the rated volume capacity of the pump.
C. However, most pump manufacturers specify that the pump
may remain in the pressure system until it is necessary to flow
more than two-thirds of the rated volume capacity. At lower
flow rates, operating in the series (pressure) position reduces
the load and the required rpm of the engine.
D. Consult the owner's manual for the specific pump being
operated to obtain information on its recommended flow rate
at which the transfer should occur.
Slide 10-54
Changeover
Slide 10-55
Changeover
E. Consult the manufacturer's recommendations for the
maximum pressure at which the transfer valve should be
operated. In most cases, the recommended maximum pressure
will not exceed SO psi (350 kPa).
Slide 10-56
Changeover
F. Because there may be a slight interruption to fireground
operations when changeover occurs, coordinate changeover
with attack crews so that lines are not shut down at critical
times.
G. Attempt to anticipate the requirements that will be placed on
the pumper as the fire fighting operation progresses and have
the pump in the proper position.
Slide 10-57
Changeover
H. If there is any question as to the proper operation of the
transfer valve, it is better to be in parallel (volume) than in
series (pressure). While the parallel (volume) position may
make it difficult to attain the desired pressure, it can supply
100 percent of the rated volume capacity at 1SO psi (1 000
kPa) at draft.
I.
Know that there is a built-in safeguard on many older pumps
that makes it physically impossible to accomplish manual
transfer while the pump is operating at high pressures.
Pumping Apparatus Driver/Operator -
Lesson 10
Slide 10-58
Changeover
10
J. Newer pumps utilize a power-operated transfer valve that can
be activated by electricity, air pressure, vacuum from the
engine intake manifold, or the water pressure itself.
Slide 10-59
Changeoyer
K. Use special care when operating power-operated transfer
valves. These valves operate at pressures as high as 200 psi
(I 380 kPa).
L. Be familiar with the manual override device installed on some
transfer valves. These overrides allow the transfer to be
operated should the power equipment fail.
M. The clapper (check) valves are essential in a multi-stage
pump. When the transfer valve is operated, the clapper valve
allows the water to escape back into the intake, and it churns
through the pump instead of building up pressure. If the
valves should stick open or closed or get debris caught in
them, the pump will not operate properly in the series
(pressure) position. Inspect the valve often to ensure that the
pump can be properly flushed.
N. Some manufacturers have used as many as four impellers
connected in series to develop pressures up to 1,000 psi
(6900 kPa) for high-pressure fog fire fighting. Pumpers that
are designed to supply high pressures must be equipped with
fire hose that is rated and tested for these pressures.
Slide 10-60
Changeover
Slide 10-61
Changeover
Objective 7 - Select facts about pump wear rings and
packing rings.
Slide 10-62
Pump Wear Rings
A. Pump wear rings
1. Any increase in the space between the pump casing and
the hub of the impeller lessens the pump's effectiveness.
This opening is usually limited to .01 inch (0.25 mm) or
less.
2. As impurities, sediment, and dirt pass through the pump,
they cause wear when they come in contact with the
impeller.
3. To restore the capacity of the pump without replacing the
pump itself, replaceable wear rings or clearance rings are
provided in the pump casing to maintain the desired
spacing.
Pumping Apparatus Driver/Operator -
Lesson 10
Slides 10-63 -10-64
Pump Wear Rings
11
4. It is best for the driver/operator not to put the pump in a
position where it might overheat, which could cause
serious pump damage.
Slides 10-65 - 10-66
Packing rungs
B. Packing rings
1. The impellers are fastened to a shaft that connects to a
gearbox. The gearbox transfers energy to spin the
impellers at a very high rate of speed. At the point where
the shaft passes through the pump casing, a semi-tight seal
must be maintained. Packing rings are used to make this
seal in most flTe pumps.
2. The most common type of packing is a material made of
rope fibers impregnated with graphite or lead. The
material is pushed into a stuffing box by a packing gland
driven by a packing adjustment mechanism. Some
centrifugal pumps are equipped with ceramic or
mechanical seals that are not adjustable.
Slide 10-67
Packing Rings
3. As packing rings wear with use, the packing gland can be
tightened and the leak controlled.
4. Where the packing rings come into contact with the shaft,
heat is developed. To overcome this, a lantern ring
(spacer) is supplied to provide cooling and lubrication. A
small amount of water leaks out and prevents excessive
heat buildup. If the packing is too tight, water is not
allowed to flow and excessive heat buildup results.
Slide 10-68
Packing Rings
Slide 10-69
Packing rungs
5. If the packing is too loose, air leaks adversely affect the
pump's ability to draft.
6. The packing only receives the needed water for lubrication
if the pump is full and operating under pressure. If the
pump is operated dry for any length of time, it can damage
the shaft.
Slide 10-70
Packing Rings
7. Some departments keep the pump drained between fire
calls, especially in cold climates. If the pump is not used
for extended periods of time, adjustment to the packing
should not be made until the pump is operating under
pressure and the packing has had a chance to seal
properly.
Pumping Apparatus Driver/Operator -
Lesson 10
12
8. Pumps equipped with mechanical seals will not drip and
will not require adjustment.
Slide 10-71
Packing Rings
9. Freezing of mechanical seals may cause damage that
necessitates immediate and complicated repair.
Objective 8 - Identify characteristics of pump
mounting and drive arrangements.
A. Auxiliary engine-driven pumps
1. Are powered by a gasoline or diesel engine independent of
an engine used to drive the vehicle
2. Some are powered by special fuels, such as jet fuel
3. Are used on:
a. Airport rescue and fire fighting (ARFF) vehicles
b. Wildland fire apparatus
c. Mobile water supply apparatus
d. Trailer-mounted fire pumps
e. Portable fire pumps
4. Offer the maximum amount of flexibility; can be mounted
anywhere on the apparatus
5. Are ideal for pump-and-roll operations (pumping water
while the apparatus is in motion)
6. Have pumping capacity of 500 gpm (2 000 Umin) or less
for wildland or mobile water supply apparatus
7. Have pumping capacity of 4,00 gpm (16 000 Umin) or
more for ARFF apparatus and trailer-mounted applications
B. Power take-off driven fire pumps
1. Are driven by a driveshaft that is connected to the power
take-off (PTO) on the chassis transmission
2. Are used on initial attack, wildland, and mobile water
supply apparatus
3. Have become popular on structural pumpers
4. Must be mounted correctly for dependable and smooth
operation; the pump gear must be mounted in a location
that allows for a minimum of angles in the driveshaft
S. Are powered by an idler gear in the truck transmission and
are under the control of the clutch; permits pump-and-roll
operation, but isn't as effective as the separate engine unit
6. Change pressure when the driver changes the vehicle
speed
7. Most limit the pump capacity to about 500 gpm (2 000
Pumping Apparatus Driver/Operator -
Slide 10-72
Auxiliary Engine-Drivcn
Pumps
Slide 10-73
Auxiliary Engine-Driven
Pumps
Slide 10-74 -10-75
Auxiliary Engine-Driven
Pumps
Slide 10-76
Power Take-Off Driven
Fire Pumps
Slide 10-77
Power Take-Off Driven
Fire Pumps
Slide 10-78 -10-79
Power Take-Off Driven
Fire Pumps
Lesson 10
13
Llmin) because of the strain on the engine's horsepower
8. Some "full torque" units permit the installation of pumps
as large as 1,250 gpm (5 000 Llmin)
C. Front-mount pumps
I. Are mounted between the front bumper and the grill
2. Are driven through a gear box and a clutch connected by a
universal joint shaft to the front of the crankshaft
3. Are set to tum the impeller of the pump faster than the
engine; the ratio is usually between 1 Y:.:I and 2Y:.:I
4. Have pump capacities as high as 1,250 gpm (5000 Llmin)
5. Are more susceptible to freezing in cold climates; can be
overcome through the use of external lines that circulate
radiator coolant through the pump body
6. Can obstruct the air flow through the vehicle's radiator and
contribute to engine overheating
7. Are in a vulnerable position in the event of a collision
8. Can be used for pump-and-roll operations
9. Most are engaged and controlled from the pump location
itself, putting the driver/operator in a vulnerable spot at
the front of the vehicle; a lock must be provided to prevent
the road transmission from being engaged while the pump
is operating
10. Engages a warning light inside the cab when in use;
vehicle should not be driven while the pump is turning
and no water is being discharged or damage to the pump
results
D. Midship pumps
1. Are mounted laterally across the frame behind the engine
and transmission
2. Are supplied power through the use of a split-shaft gear
case located in the drive line between the transmission and
the rear axle
3. Have power diverted from the rear axle by shifting of a
gear and collar arrangement inside the gear box
4. Are driven by a series of gears or a drive chain
5. Are arranged so that the impeller turns faster than the
engine, usually 1 Y:. to 2Y:. times as fast
6. Have a transfer case inside the cab
7. Should be engaged inside the cab and the road
transmission put in the proper gear
Note: To be sure that the transmission is in the correct
gear, observe the speedometer reading after the pump is
Pumping Apparatus Driver/Operator -
Lesson 10
Slide 10-80
Front-Mount Pumps
Slide 10-81
Front-Mount Pumps
Slide 10-82
Front-Mount Pumps
Slide 10-83
Front-Mount Pumps
Slide 10-84 - 10-85
Front-Mount Pumps
Slide 10-86
Midship Pumps
Slide 10-87
Midship Pumps
Slide 10-88
Midship Pumps
14
engaged. With the engine idling and the pump engaged,
most speedometers read between 10 and IS mph (16 kmlh
to 24 km/h) . Some newer apparatus may be designed so
that the speedometer does not go above mph (km/h)
when the pump is engaged.
8. Require that the clutch be disengaged and the road
transmission be placed in neutral to prevent damage to the
gears
9. Do not have the ability to pump-and-roll
10. Must have a lock on the transmission or shift lever to hold
the automatic transmission gear selector in the proper gear
for pumping
II . May include a green light on the dash that, when lit,
indicates that it is safe to begin the pumping operation
12. Hydrostatic pumps
a. Are driven by a shaft from the front of the vehicle's
engine, which turns a pump that drives a midshipmounted or rear-mounted centrifugal water pump
b. Have up to 1,000 gpm (4 000 Llmin capacity)
c. Can be used for both stationary and pump-and-roll
operations
d. Do not output according to speed of the engine
e. Can significantly reduce the power available for
driving the vehicle
f. Can sometimes take all of the engine output to
produce maximum flow
°
E. Rear-mount pumps
I . Have become increasingly popular in recent years
2. Advantages
a. Provide more even weight distribution on the
apparatus chassis
b. Allow the apparatus to have more compartment space
for tools and equipment
3. Disadvantage - May expose driver/operator to oncoming
traffic
4. May be powered by split-shaft transmission or PTO
5. Are connected to the transmission by a driveshaft
Slide 10-89
Midship Pumps
Slide 10-90 - 10-91
Midship Pumps
Slide 10-92
Hydrostatic Pumps
Slide 10-93
Hydrostatic Pumps
Slide 10-94
Rear-Mount Pumps
Slide 10-95 - 10-96
Rear-Mount Pumps
Objective 9 - Answer questions about intake and
discharge piping.
Slide 10-97
Piping Systems
A. Piping systems
1. Components
Pumping Apparatus Driver/Operator - Lesson 10
15
2.
3.
4.
5.
a. Intake piping
b. Discharge piping
c. Pump drains
d. Valves
Must be of a corrosion-resistant material; most are
constructed of cast iron, brass, stainless steel, or
galvanized steel
May include rubber hoses in certain locations
Must be able to withstand a hydrostatic test of 500 psi
(3 450 kPa) before being placed into service
Should be designed so that they run as straight as possible,
with a minimum of bends or turns
B. Intake piping
1. Piping that connects the pump and the onboard water tank
a. Should be sized so that pumpers with a capacity of
500 gpm (1 900 Llmin) or less should be capable of
flowing 250 gpm (950 Llmin) from the booster tank;
pumpers with capacities greater than 500 gpm (1 900
Llmin) should be able to flow at least 500 gpm (1 900
Llmin)
b. May be as large as 4 inches (100 mm) in diameter
c. All are equipped with check valves, which prevent
damage to the tank if the tank-to-pump valve opens
when water is being supplied to the pump under
pressure
2. Piping that is used to connect the pump to an external
water supply - Is located below the eye of the impeller,
so that no air is trapped in the pump during the priming
operation
3. The primary intake into the fire pump is through largediameter piping and connections. Intake piping is round
in shape at the point where the intake hose connects; it
then tapers to a square shape.
4. Additional large-diameter intakes may be piped to the
front or rear of the apparatus.
5. Front and rear intakes should be considered auxiliary
intakes.
6. Pumps that have a capacity of 1,500 gpm (6 000 Llmin) or
greater may require more than one large intake connection
at each location.
7. Additional intake lines are provided for use in relay
operations or anytime water is being received through
small-diameter supply lines; these usually have 2Yz-inch
hose couplings.
Pumping Apparatus Driver/Operator - Lesson 10
Slide 10-98
Piping Systems
Slide 10-99
Intake Piping
Slide 10-100
Intake Piping
Slide 10-101
Intake Piping
Slide 10-102
Intake Piping
Slide 10-103
Intake Piping
Slide 10-104
Intake Piping
16
Slide 10-105
Discharge Piping
C. Discharge piping
I. Enough 2v,-inch (65 mm) or larger discharge outlets must
be provided in order to flow the rated capacity of the fire
pump.
2. Apparatus with a rated pump capacity of750 gpm (2 850
Umin) or greater must be equipped with at least two 211,inch (65 mm) discharges.
3. Apparatus with a rated pump capacity less than 750 gpm
(2 850 Umin) are only required to have one 2v,-inch (65
mm) discharge.
Slide 10-106
Discharge Piping
4. Apparatus may be equipped with discharges that are less
than 2v,-inches (65 rum) in size; discharges to which
smaller handlines are attached must be supplied by at least
2-inch (50 mm) piping.
Slide 10-107
Discharge Piping
5. Discharge piping is constructed of the same material as
intake piping.
6. Discharges are usually equipped with a locking ball valve,
and should always be kept locked when they are open to
prevent movement.
7. All valves should be designed so that they are easily
operable at pressures of up to 250 psi (I 724 kPa).
8. Tank fill line
Slide 10-108
Tank Fill Line
a. Should be provided from the discharge side of the
pump
b. Allows the tank to be filled without making any
additional connections when the pump is being
supplied from an external supply source
c. Provides a means of replenishing the water carried in
the tank after the initial attack has been made from the
water tank on the apparatus
d. Must be at least I-inch (25 mm) in diameter for tanks
less than 1,000 gallons (3 785 L)
e. Must be at least 2-inches (50 mm) in diameter for
tanks 1,000 gallons (3 785 L) or larger
f. Can be used to circulate water through the pump to
prevent overheating when no lines are flowing
9. Circulator valve and booster line cooling valve
a. Both prevent overheating by enabling water to be
dumped into the tank or outside the tank on the ground
Slide 10-109
Tank Fill Line
Slide 10-110
Circulator Valve and Booster
Line Cooling Valve
b. May not discharge enough water to keep the pump
cool during prolonged operations; it may be necessary
to discharge water through a waste or dump line
Objective 10 -
Select facts about valves.
Pumping Apparatus Driver/Operator -
Lesson 10
17
Objective 11 actuators.
Distinguish between types of valve
Slide 10-111
Valves
A. Valves
1. Control most of the intake and discharge lines from the
pump
2. Must be airtight
3. May require repair as they age and are subjected to
frequent use
B. Ball-type valves
1. Permit full flow through the lines with a minimum of
friction loss
2. Use one of two types of actuators
a. Push-pull handles
I) Use a sliding gear-tooth rack that engages a sector
gear connected to the valve stem
2) Have a mechanical advantage due to the gear
arrangement that makes it easier to operate under
pressure
3) Allow precise values of pressure to be set when
adjusting individual lines
4) Can be mounted in a location remote from the pum
panel
5) Have a flat handle that can be used to lock the valve
in any position by a 90-degree twist of the handle
6) Must be pulled straight-out, in a level manner
b. Quarter-turn handles
1) Have a simpler mechanical linkage
2) Have a handle mounted directly on the valve stem
3) Are opened or closed by a 90-degree movement of
the handle
4) Lock by rotating the handle in a clockwise direction
5) Some lock automatically when the handle is
released, but the majority require a positive action
C. Hydraulically, pneumatically, or electrically controlled valves
I. Use a ball-type valve that is opened by a toggle switch or
touch screen on the pump operator's panel
2. Display readouts of how far the valve is opened
3. Indicate on the panel which direction to operate the switch
in order to open or close the valve
Pumping Apparatus Driver/Operator -
Slide 10-112
Ball-Type Valves
Slide 10-113
Push-Pull Handles
Slides 10-114 -10-115
Push-Pull Handles
Slides 10-116 - 10-117
Quarter-Turn Handles
Slide 10-118
Hydraulically, Pneumatically,
or Electrically Controlled
Valves
Lesson 10
18
D. Gate or butterfly valves
I. Are most commonly used on large-diameter intakes and
discharges
2. May be equipped with hydraulic, pneumatic, or electric
actuators
3. Are commonly used as remote-operated dump controls on
water tenders
4. Gate valves are most often operated by a handwheel,
butterfly valves by quarter-tum handles.
Objective 12 bleeder lines.
Slide 10-119
Gate or Butterfly Valves
Slide 10-120
Gate or Butterfly Valves
List purposes of drain valves and
A. Drain valves
I. Provide a way for the driver/operator to relieve the
pressure from the hoseline after the discharge valve and
nozzle have both been closed
2. Allow for draining and disconnecting unused lines even
when the pump is still in service
3. Remove water from the system in climates where freezing
might occur
B. Bleeder lines
I. Allow air to be removed from system before it enters fire
pump
2. Make it possible to change over to the supply line without
interrupting fire streams
Slide 10-121
Drain Valves
Slide 10-122
Bleeder Lines
Objective 13 - Identify characteristics of various
automatic pressure control devices.
A. Automatic pressure control devices
I. When a pump is supplying multiple attack lines, any
sudden flow change in one line can cause a pressure surge
on the otber.
2. Some type of automatic pressure regulation is essential to
ensure the safety of personnel operating the hoselines.
3. NPFA 1901 requires some type of pressure control device
to be part of any fire apparatus pumping system.
4. The device must operate within 3 to 10 seconds after the
discharge pressure rises and must not allow the pressure to
exceed 30 psi above the set level.
Pumping Apparatus Driver/Operator - Lesson 10
Slide 10-123
Automatic Pressure
Control Devices
Slide 10-124
Automatic Pressure
Control Devices
19
B. Reliefvalves
I. Are of two types (or concepts)
a. Those that relieve excess prcssure on the discharge
side of the pump
b. Those that relieve excess pressure on the intake side of
the pump
2. Discharge pressure relief valves
a. Are an integral part of all fire pumps that are not
equipped with a pressure governor
b. Are sensitive to pressure change and have the ability
to relieve excessive pressure within the pump
discharge
c. Have an adjustable spring-loaded pilot valve that
actuates the relief valve to bypass water from the
discharge to the intake chamber of the pump
d. Types
1) Spring-controlled pilot valve - A spring-loaded
pilot valve actuates a relief valve to bypass water
from pump discharge to pump intake
2) Alternative spring-controlled pilot valve - A
spring-loaded pilot valve compresses, allowing
water to flow through an opening in its housing,
through the bleed line, and into the pump intake,
which forces the churn valve to open and allows
water to flow from the discharge into the intake
e. Are quick to react to overpressure conditions, but are
somewhat slower to reset back to "all-closed"
positions
f. Take a short time for the pump to return to normal
operation
3. Intake pressure relief valves
a. Are intended to reduce the possibility of damage to the
pump and discharge hoselines caused by water
hammer
b. Types
I) Supplied by the pump manufacturer and is an
integral part of the pump intake manifold
2) Add-on device that is screwed onto the pump intake
connection
c. Should be set to open when the intake pressure rises
more than 10 psi (70 kPa) above the desired operating
pressure
Slide 10-125
Relief Valves
Slide 10-126
Discharge Pressure
Relief Valves
Slide 10-127
Discharge Pressure
Relief Valves
Slide 10-128
Discharge Pressure
Relief Valves
Slide 10-129
Intake Pressure Relief Valves
Slide 10-130
Intake Pressure Relief Valves
Slide 10-131
Pressure Governor
C. Pressure governor
Pumping Apparatus Driver/Operator - Lesson 10
20
I . Regulates pressure on centrifugal pumps
2. Regulates the power output of the engine to match pump
discharge requirements
3. Relieves excessive pressure that is generally caused by
shutting down one or more operating hoselines
4. Varies with each manufacturer's designs; may be attached
to either a regular or an auxiliary throttle
5. Can be used in connection with a throttle control, engine
throttle, and/or pump discharge
6. Piston assembly governor - Fits onto the carburetor
(gasoline engines) or throttle link (diesel engines) and
reduces or increases the engine speed under the control of
a rod connected to a piston in a water chamber
7. Electronic governor - Uses a pressure-sensing element
connected to the discharge manifold to control the action
of an electronic pump amplifier that compares pump
pressure to an electrical reference point
Slides 10-132 - 10-133
Pressure Governor
Slide 10-134
Pressure Governor
Slide 10-135
Pressure Governor
Objective 14 - Match pump primers to their
descriptions and operating techniques.
Slide 10-136
Positive Placement Primers
A. Positive displacement primers
1. Are the most common choice of manufacturers and fire
departments
2. May be rotary vane or rotary gear type
3. May be driven off the transfer case of the transmission
a. Are not as common as electric-driven
b. Should operate with an engine rpm around 1,000 to
2,000
4. May be electric-driven - Can be operated effectively,
regardless of engine speed
5. Have an inlet connected to a primer control valve that is in
tum connected to the fire pump
6. Use an oil supply or some other type of fluid to seal the
gaps between the gears and the case and to act as a
preservative and minimize deterioration
Slide 10-137
Positive Placement Primers
Slide 10-138
Positive Placement Primers
B. Oil-less primers
I . Are environmentally friendly
2. Are constructed of space-age materials that do not require
lubrication
3. Do not discharge oil in the primary process
4. May be installed on new apparatus or in apparatus that
Pumping Apparatus Driver/Operator -
Lesson 10
Slide 10-139
Oil-Less Primers
21
came with conventional oil-lubricated primers as original
equipment
Slide 10-140
Exhaust Primers
C. Exhaust primers
I. Are still found on many small skid-mounted pumps and
some older pieces of apparatus
2. Operate on the same principle as a foam eductor
3. Require high engine rpm to operate
4. Are not very efficient
5. Require a great deal of maintenance
6. Require that any air leaks in the pump be kept to an
absolute minimum and that the suction hose and gaskets
be kept in good condition
Slide 10-141-10-142
Exhaust Primers
Slide 10-143
Vacuum Primers
D. Vacuum primers
1. Are the simplest type of primer
2. Were common on older, gasoline-powered fire apparatus
3. Prime the pump by connecting a line from the intake
manifold of the engine to the intake of the fire pump with
a valve connected in the line to control it
4. Can draw water through the pump and into the intake
manifold, causing damage to the engine; can be prevented
with a check valve
5. Work best at low engine rpm
Slide 10-144
Vacuum Primers
Objective 15 - Match pump panel controls and
instruments to their descriptions.
A. NFPA 1901 requires, as a minimum, the following:
1. Master pump intake pressure indicating device
2. Master pump discharge pressure indicating device
3. Weatherproof tachometer
4. Pumping engine coolant temperature indicator
5. Pumping engine oil pressure indicator
6. Pump overheat indicator
7. Voltmeter
8. Pump pressure controls (discharge valves)
9. Pumping engine throttle
10. Primer control
II. Water tank to pump valve
12. Tank fill valve
13. Water tank level indicator
Slide 10-145
Pump Panel Controls
Required by NFPA 1901
Slide 10-146
Pump Panel Controls
Required by NFPA 1901
Pumping Apparatus Driver/Operator - Lesson 10
22
B. Master intake gauge (vacuum or compound gauge)
I . Is used to determine the water pressure entering the pump
2. Must be connected to the intake side of the pump
3. Must be capable of measuring either positive pressure or a
vacuum
4. Is usually calibrated from 0 to 600 psi (0 kPa to 4 137
kPa) positive pressure from 0 to 30 inches (0 mm to 762
mm) of mercury (vacuum) on the negative side
5. Provides an indication of the residual pressure when the
pump is operating from a hydrant or is receiving water
through a supply line from another pump
C. Master pump discharge pressure gauge
I. Registers the pressure as it leaves the pump, but before it
reaches the gauges for each individual discharge line
2. Must be calibrated to measure 600 psi (4 13 7 kPa) unless
the pumper is equipped to supply high-pressure fog
streams, in which case the gauge may be calibrated up to
1,000 psi (6 900 kPa)
3. Must have external connections to allow installation of
calibrated gauges when service tests are performed
Slide 10-147
Master Intake Gauge (Vacuum
or Compound Gauge)
Slide 10-148
Master Intake Gauge (Vacuum
or Compound Gauge)
Slide 10-149
Master Pump Discharge
Pressure Gauge
Slide 10-150
Tachometer
D. Tachometer
1. Records the engine speed in revolutions per minute (rpm)
2. Is useful as a means of trouble analysis when difficulty
with the pump is encountered - a gradual increase in the
amount of rpm required to pump the rated capacity
indicates wear in the pump and a need for repairs
Slide 10-151
Pumping Engine Coolant
Temperature Indicator
E. Pumping engine coolant temperature indicator
I. Shows the temperature of the coolant in the engine that
powers the fire pump
2. May indicate temperature of the main vehicle engine or
the pump engine
F. Pumping engine oil pressure indicator
I . Shows that an adequate supply of oil is being delivered to
the critical areas of the engine that is powering the fire
pump
2. Indicates pending problems by showing any significant
deviation from the normal oil pressure
Pumping Apparatus Driver/Operator -
Lesson 10
Slide 10-152
Pumping Engine Oil
Pressure Indicator
23
G. Pump overheat indicator the pump overheats
Warns the driver/operator when
Slide 10-153
Pump Overheat Indicator
Slide 10-154
Voltmeter
H. Voltmeter - Provides a relative indication of battery
condition and alternator output
I.
Pump pressure indicators (discharge gauges)
1. Indicate actual pressure applied to hoselines
2. Must be connected to the outlet side of the discharge valve
so that the pressure being reported is the pressure actually
being applied to the hoselines after the valve
Slide 10-155
Pump Pressure Indicators
(Discharge Gauges)
3. Allow pressure in each discharge to be adjusted down
from the overall pump discharge pressure if necessary
4. May be included on master stream devices or the lines that
supply them; effective master streams are impossible to
maintain without the proper pressure
Slide 10-156
Pump Pressure Indicators
(Discharge Gauges)
5. May be substituted by flowmeter readouts, but master
intake and pressure gauges are still required
Slide 10-157
Pumping Engine Throttle
J. Pumping engine throttle
1. Is used to increase or decrease the speed of the engine that
is powering the fire pump
2. Most common is a knob that is turned one way or another
until the desired rpm/pressure is achieved
3. Is also available with automatic throttle controls
Slide 10-158
Primer Control
K. Primer control - Is used to operate the priming device when
the pump is going to be used to draft from a static water
supply
L. Water tank level indicator
1. Is intended to let the driver/operator know how much
water is remaining in the onboard water tank
2. Allows the driver/operator to anticipate how much longer
attack hoselines may be supplied before an external water
supply source is needed
3. Uses a series oflights on the pump operator's panel that
indicate the amount of water in the tank by one-quarter
levels (empty, It., II" 'I., full)
Slide 10-159
Water Tank Level Indicator
Objective 16 - State the primary function of an
auxiliary cooler.
Pumping Apparatus Driver/Operator -
Lesson 10
24
Objective 17 - Explain the operation of marine- and
immersion-type auxiliary coolers.
Slide 10-160
Auxiliary Coolers
A. Function - To control the temperature of coolant in the
apparatus engine during pumping operations
B. Marine-type - Is inserted into one of the hoses used in the
engine cooling system so that the engine coolant must travel
through it as it circulates through the system
Slide 10-161
Auxiliary Coolers
C. Immersion-type - The water being supplied by the fire pump
passes through a coil or some type of tubing mounted inside
the cooler so that it is immersed in the coolant.
Slide 10-162
Auxiliary Coolers
Summary
Slide 10-163
Summary
A. Vv'bile some water systems supply sufficient pressure to
operate nozzles and other fire fighting equipment without the
pressure being increased, most fire situations require the fire
department to increase the available water pressure.
Slide 10-164
Summary
B. In most cases, added pressure is provided by a fire pump built
into a piece of fire apparatus - a conventional or specialized
fire department pumper.
C. To do their jobs properly, driver/operators must know the
operating theory as well as the operational capabilities and
limitations of the pumping apparatus within their departments.
Discussion Questions
I. Explain how a piston pump operates.
2. Explain how a rotary pump operates.
Slide 10-165
Discussion Questions
3. Name the three parts of a centrifugal pump.
4. Explain how a centrifugal pump operates.
5. What is changeover?
6. Explain the operation of auxiliary engine-driven pumps and
PTO driven pumps.
Slide 10-166
Discussion Questions
7. Name the two types of actuators used in ball-type valves.
8. What is the primary function of an auxiliary cooler?
Pumping Apparatus Driver/Operator -
Lesson 10
25
Pumping Apparatus Driver/Operator
Lesson 10 -
Fire Pump Theory
Lesson Quiz
Name ________________________ Date _ _ _ _ _ _ _ ___
1. The two basic types of positive displacement pumps are:
A.
B.
C.
D.
vane and gear pumps.
piston and rotary pumps.
venturi and centrifugal pumps.
high pressure and low pressure pumps.
____ 2. The output ofthe piston positive displacement pump is determined by the size of the
cylinder and the:
A.
B.
C.
D.
weight of the piston.
diameter of the piston.
length of the piston.
speed of the piston travel.
3. The _
A.
B.
C.
D.
of the centrifugal pump transmits energy in the form of velocity to the water.
casmg
volute
impeller
rotary gear
4. What is changeover?
A.
B.
C.
D.
The process of switching between the pressure and volume position
The process of changing from a single-stage pump to a multi-stage pump
The process of velocity being converted to pressure within a centrifugal pump
The process of changing from a positive displacement pump to a centrifugal pump
____ 5. Most manufacturers recommend that the transfer valve should be operated at a maximum
pressure of:
A.
B.
C.
D.
10 psi (70 kPa).
20 psi (140 kPa).
35 psi (245 kPa).
50 psi (350 kPa).
____ 6. Any increase in the space between the pump casing and the hub of the impeller lessens the
pump's effectiveness. This opening is usually limited to _ or less.
A. om inch (0.25 mm)
B. 0.02 inch (0.5 mm)
Pumping Apparatus Driver/Operator -- Lesson 10
26
C. 0.03 inch (0.75 mm)
D. 0.04 inch (1.0 mm)
7. Ifthe pump is operated _
A.
B.
C.
D.
for any length oftime, it can damage the shaft.
dry
wet
hot
cold
8. Which pumps can obstruct air flow through the vehicle's radiator and contribute to engine
overheating?
A.
B.
C.
D.
Midship pumps
Front-mount pumps
Auxiliary engine-driven pumps
Power take-off driven fire pumps
9. Which pumps change pressure when the driver changes the vehicle speed?
A.
B.
C.
D.
Midship pumps
Front-mount pumps
Auxiliary engine-driven pumps
Power take-off driven fire pumps
_ _ 10. All discharge valves should be designed so that they are easily operable at pressures of up
to:
A.
B.
C.
D.
100 psi (689 kPa).
150 psi (1 035 kPa).
200 psi (1 379 kPa).
250 psi (1 724 kPa).
Pumping Apparatus Driver/Operator -
Lesson 10
27
Pumping Apparatus Driver/Operator
Lesson 10 -
Fire Pump Theory
Lesson Quiz Answers
1. B
2. D
3. C
4. A
5. D
6. A
7. A
8. B
9. D
10. D
Pumping Apparatus Driver/Operator - Lesson 10
28
Pumping Apparatus Driver/Operator
Lesson 10 -
Fire Pump Theory
Written Test
Name ___________________________________________ Date _________________
Note: For each tested objective, you must achieve the specified number of points. For example, in a test item
designated (9/12), you must achieve at least 9 of the 12 points possible.
Objective 1:
Select facts about positive displacement pumps. Write the correct letters on the blanks.
(1 pt. each, 7/10)
_ _ 1. Positive displacement pumps have largely been replaced by _
pump on modem fire apparatus.
A.
B.
C.
D.
Piston pumps
Venturi pumps
Rotary pumps
Centrifugal pumps
2. Positive displacement pumps are used as _
during drafting operations.
A.
B.
C.
D.
for use as the main fire
devices to get water into centrifugal pumps
Series
Priming
Parallel
Two-speed
_ _ 3. The two basic types of positive displacement pumps are:
A.
B.
C.
D.
vane and gear pumps.
piston and rotary pumps.
venturi and centrifugal pumps.
high pressure and low pressure pumps.
4. Piston positive displacement pumps may be:
A. gear or vane models.
B. in SERIES or in PARALLEL.
C. single-acting or double-acting.
D. internal combustion or external combustion.
_ _ 5. The output of the piston positive displacement pump is determined by the size of the
cylinder and the:
A.
B.
C.
D.
weight of the piston.
diameter of the piston.
length of the piston.
speed of the piston travel.
Pumping Apparatus Driver/Operator -- Lesson 10
29
6. The capacity of a piston positive displacement pump is usually determined by the size of
the:
A.
B.
C.
D.
plpmg.
cylinder.
gear pump.
centrifugal pump.
7. Rotary positive displacement pumps are the _
A.
B.
C.
D.
of all fire apparatus pumps in design.
simplest
most complex
least dependable
most sophisticated
8. Rotary positive displacement pumps are now used as:
A.
B.
C.
D.
multi cylinder, PTO-driven pumps.
auxiliary pumps for wildland pump and roll operations.
large-capacity, high-volume, low pressure, master stream pumps.
small-capacity, booster-type pumps, low-volume high pressure pumps, and priming
pumps.
9. The total amount of water that can be pumped by a rotary gear pump depends on the size
ofthe _ and the speed of rotation.
A.
B.
C.
D.
gear tooth
depth of the gears
pockets in the gears
diameter of the gears
_ _ 10. Rotary vane pumps are constructed with moveable elements that automatically
compensate for:
A.
B.
C.
D.
wear.
pressure buildup.
warped gear teeth.
stripped hub threads.
Objective 2:
Complete statements about the operation of positive displacement fire pumps. Write
the correct answers on the blanks provided. (1 pt. each, 14118)
Piston pumps
I. Piston pumps contain a piston that moves back and forth or up and down inside a cylinder. The
pressure developed by this action causes
and
valves to operate
automatically and provides for the movement of the water through the pump.
2. As the piston is driven forward, the
within the cylinder is compressed, creating a
higher pressure inside the pump than the atmospheric pressure in the discharge manifold. This
pressure causes the discharge valve to open and the air to escape through the discharge lines.
3. This action continues until the piston completes its travel on the _____ stroke and stops. At
that point, pressures equalize and the discharge valve closes.
Pumping Apparatus Driver/Operator -
Lesson 10
30
•
4. As the piston begins the return stroke, the area within the cylinder behind the piston _ _ _ __
and the pressure
, creating a partial vacuum. At this time, the intake valve opens,
to enter the pump.
allowing some of the air from the
5. As the air from the suction hose is evacuated and enters the cylinder, the pressure within the hose
. Atmospheric pressure forces the water to rise
and the intake area of the pump is
within the hose until the piston completes its travel and the intake valve closes.
6. As the forward stroke is repeated, the air is again forced out of the discharge. On the return
stroke, more of the air in the intake section is removed and the column of water in the suction
hose is raised. This action is repeated until all the air has been removed and the intake stroke
results in water being introduced into the cylinder. The pump is now considered to be
_____, and further strokes cause water to be forced into the discharge instead of air.
Rotary gear pumps
I. The rotary gear pump consists of
gears that rotate in a tightly meshed pattern inside
a watertight case. The gears are constructed so that they contact each other and are in close
proximity to the case.
2. With this arrangement, the gears within the case form _____ and _____ pockets as
they tum from the intake to the outlet.
3. As each gear tooth reaches the _____ chamber, the air or water contained in that pocket is
forced out of the pump.
4. As the
returns to the intake side of the pump, the gears are meshed tightly enough to
prevent the water or air that has been discharged from returning to the intake.
Rotary vane pumps
1. The rotor is mounted off-center inside the housing. The distance between the
and the
---:--;-;-----:-_-; is much greater at the intake than it is at the discharge. The vanes are free to move
within the slot where they are mounted.
2. As the rotor turns, the vanes are forced against the housing by __________'
3. When the surface of the vane that is in contact with the casing becomes
, centrifugal
force causes it to extend further, thus automatically maintaining a tight fit.
4. As the rotor turns,
is trapped between the rotor and the casing in the pockets formed
by adjacent vanes.
5. As the vanes tum, this pocket becomes
, which compresses the air and causes
pressure to build up. This pocket becomes even smaller as the vanes progress toward the
discharge opening.
6. At this point, the pressure reaches its
level, forcing the trapped air out of the pump.
The air or water is prevented from returning to the intake by the close spacing of the rotor at that
point.
7. As in the rotary gear pump, the air being evacuated from the intake side causes a _ _ _ __
pressure (similar to a vacuum), and water is forced into the pump by atmospheric pressure until
the pump fills with water.
8. At this point, the pump is _____ and forces water out of the discharge in the same manner
as air was forced out.
Objective 3:
Pumping Apparatus Driver/Operator - Lesson 10
31
Answer questions about centrifugal pumps. Write the correct letters on the blanks. (1 pt.
each,6/8)
_ _ 1. The centrifugal pump is classified as a _
water with each revolution.
A.
B.
C.
D.
fire pump
split case pump
positive displacement pump
nonpositive displacement pump
_ _ 2. The centrifugal pump imparts _
itself.
A.
B.
C.
D.
to the water and converts it to pressure within the pump
velocity
viscosity
turbidity
turgidity
_ _ 3. The _
A.
B.
C.
D.
because it does not pump a definite amount of
of the centrifugal pump transmits energy in the form of velocity to the water.
casmg
volute
impeller
rotary gear
_ _ 4. The _ of the centrifugal pump collects the water and confines it in order to convert the
velocity to pressure.
A.
B.
C.
D.
casmg
volute
impeller
rotary gear
5. The _ _ of the centrifugal pump is a water passage that gradually increases in crosssectional area as it nears the pump discharge outlet.
A.
B.
C.
D.
casmg
volute
impeller
rotary gear
6. The impeller in a centrifugal pump rotates very rapidly within the casing, generally from
_rpm.
A.
B.
C.
D.
500 to 1,000
1,000 to 1,500
1,000 to 2,000
2,000 to 4,000
7. The volume capacity ofthe pump is dependent on the size of the _
greater it is, the greater the flow capacity.
of the impeller: The
A. hub
B. eye
C. volute
D. impeller
Pumping Apparatus Driver/Operator -
Lesson 10
32
8. Which of the following is NOT a factor that influences a centrifugal fire pump's discharge
pressure?
A.
B.
C.
D.
Amount of water being discharged
Speed at which the impeller is turning
Size of the volute and impeller inside the pump
Pressure of water when it enters the pump from a pressurized source
Objective 4:
Complete statements about the operation of centrifugal pumps. Write the correct
answers on the blanks provided. (1 pt. each, 3/5)
I. The operation of a centrifugal pump is based on the principle that a rapidly revolving disk tends
to throw water introduced at its center toward the
of the disk. The faster
the disk is turned, the farther the water is thrown, or the more velocity the water has.
2. If the water is contained at the edge of the disk, the water at the center of the container begins to
move outward. The velocity created by the spinning disk is converted to
by
confining the water within the container.
3. The water is limited in its movement by the walls of the container and moves
in the
path of least resistance.
4. This shows that pressure has been created on the water. The height to which it raises, or the extent
to which it overcomes the force of gravity, depends upon the speed of_--,--_-.,..._
5. The centrifugal pump consists of two parts: an impeller and a casing. The impeller transmits
_:--___ in the form of velocity to the water. The casing collects the water and confines it in
order to convert the velocity to
. Then the casing directs the water to the discharge of
the pump.
Objective 5:
Match centrifugal pumps to their characteristics. Write the correct letters on the blanks.
Letters will be used more than once. (1 pt. each, 10/12)
1. Have impellers that take water from a source and
deliver it to the discharge
2. Have impellers that are usually mounted on a single
shaft driven by a single drivetrain
3. Work by all water from the manifold being directed
into the eye of the first impeller, increasing the pressure
and discharging 50 to 70 percent of the volume capacity
through the transfer valve and into the eye of the second
impeller
A. Single-stage centrifugal fire
pumps
B. Multi-stage centrifugal fire
pumps
C. Multi-stage pumps in the
parallel (volume) position
D. Multi-stage pumps in the
series (pressure) position
4. Are constructed with a single impeller
5. Are used on front-mount pumps, PTOs, separate
engine-driven and midship transfer pumps
6. Cause impellers to be capable of delivering their rated
pressure while flowing 50 percent of the rated capacity;
therefore, the total amount of water the pump can
deliver is equal to the sum of each stage
7. Have identical impellers that are the same capacity
Pumping Apparatus Driver/Operator -
Lesson 10
33
_ _ 8. Have the capability of connecting the stages in series
for maximum pressure or in parallel for maximum
volume by use of a transfer valve
9. May provide capacities up to 2,000 gpm (8 000 Llmin)
_ _ 10. Have a second impeller that increases the pressure and
delivers the water at the higher pressure into the pump
discharge port
_ _ II. May have a double suction impeller to minimize the
lateral thrust oflarge quantities of water entering the
eye of the impeller
_ _ 12. Have an impeller for each stage mounted within a
single housing
Objective 6:
Answer questions about changeover. Write the correct letters on the blanks. (1 pt. each,
4/5)
1. What is changeover?
A.
B.
C.
D.
The process of switching between the pressure and volume position
The process of changing from a single-stage pump to a multi-stage pump
The process of velocity being converted to pressure within a centrifugal pump
The process of changing from a positive displacement pump to a centrifugal pump
2. SOPs in some departments specify that the transfer valve stay in the pressure position
until it is necessary to supply more than _ the rated volume capacity of the pump.
A.
B.
C.
D.
one-eighth
one-fourth
one-third
one-half
_ _ 3. Most manufacturers specify that the pump may remain in the pressure system until it is
necessary to flow more than _ of the rated volume capacity.
A.
B.
C.
D.
one-fourth
one-half
two-thirds
three-fourths
_ _ 4. Most manufacturers recommend that the transfer valve should be operated at a maximum
pressure of:
A.
B.
C.
D.
10 psi (70 kPa).
20 psi (140 kPa).
35 psi (245 kPa).
50 psi (350 kPa).
5. While the parallel (volume) position may make it difficult to attain the desired pressure, it
can supply _ percent of the rated volume capacity at _ psi (kPa).
A. 50%, 50 psi (350 kPa)
B. 50%,100 psi (700 kPa)
Pumping Apparatus Driver/Operator - Lesson 10
34
C. 100%, 100 psi (700 kPa)
D. 100%, 150 psi (I 000 kPa)
Objective 7:
Select facts about pump wear rings and packing rings. Write the correct letters on the
blanks. (1 pt. each, 7110)
_ _ 1. Any increase in the space between the pump casing and the hub of the impeller lessens the
pump's effectiveness. This opening is usually limited to _ or less.
A. om inch (0.25 mm)
B. 0.02 inch (0.5 mm)
C. 0.03 inch (0.75 mm)
D. 0.04 inch (1.0 mm)
2. To restore pump capacity without replacing the pump itself, replaceable wear rings (or
_ rings) are provided in the pump casing to maintain the desired spacing.
A.
B.
C.
D.
pump
packing
impeller
clearance
3. Packing rings are used to make a seal at the point where the shaft passes through the:
A.
B.
C.
D.
volute.
impeller.
gearbox.
pump casing.
_ _ 4. The most common type of packing material is made of rope fibers impregnated with:
A.
B.
C.
D.
grease.
ceramics.
graphite or lead.
powdered Teflon™.
5. As packing rings wear with the operation of the shaft, the _
leak controlled.
A.
B.
C.
D.
can be tightened and the
lantern ring
packing gland
gear sprocket
hub adjusting nut
6. Which of the following are supplied to provide cooling and lubrication between the
packing rings and shaft?
A.
B.
C.
D.
Lantern rings
Packing glands
Gear sprockets
Hub adjusting nuts
_ _ 7. A smaIl amount of_ should leak out around the packing and prevent excessive heat
buildup.
A. air
Pumping Apparatus Driver/Operator -
Lesson 10
35
B. water
C. grease
D. graphite
_ _ 8. Ifthe pump is operated _
for any length oftime, it can damage the shaft.
A. dry
B. wet
C. hot
D. cold
9. Pumps equipped with _
A.
B.
C.
D.
will not drip and will not require adjustment.
lantern rings
packing seals
gear sprockets
mechanical seals
_ _ 10. __ of mechanical seals may cause damage that necessitates immediate and complicated
repair.
A.
B.
C.
D.
Aging
Freezing
Overheating
Pressurization
Objective 8:
Identify characteristics of pump mounting and drive arrangements. Write the correct
letters on the blanks. (1 pt. each, 13/18)
1. Which pumps are powered by a gasoline or diesel engine independent of an engine used to
drive the vehicle?
A.
B.
C.
D.
Midship pumps
Front-mount pumps
Auxiliary engine-driven pumps
Power take-off driven fire pumps
2. Which pumps have power diverted from the rear axle by shifting of a gear and collar
arrangement inside the gear box?
A.
B.
C.
D.
Midship pumps
Rear-mount pumps
Front-mount pumps
Power take-off driven fire pumps
_ _ 3. Which pumps can obstruct air flow through the vehicle's radiator and contribute to engine
overheating?
A.
B.
C.
D.
Midship pumps
Front-mount pumps
Auxiliary engine-driven pumps
Power take-off driven fire pumps
4. Which pumps change pressure when the driver changes the vehicle speed?
A. Midship pumps
Pumping Apparatus Driver/Operator - Lesson 10
36
B. Front-mount pumps
C. Auxiliary engine-driven pumps
D. Power take-off driven fire pumps
5. Which pumps do not have the ability to pump-and-roll?
A.
B.
C.
D.
Midship pumps
Rear-mount pumps
Front-mount pumps
Power take-off driven fire pumps
6. Which pumps provide more even weight distribution on the apparatus chassis?
A.
B.
C.
D.
Midship pumps
Rear-mount pumps
Front-mount pumps
Power take-off driven fire pumps
7. Which pumps are supplied power through the use of a split-shaft gear case located in the
drive line between the transmission and the rear axle?
A.
B.
C.
D.
Midship pumps
Rear-mount pumps
Front-mount pumps
Power take-off driven fire pumps
8. Which pumps allow the apparatus to have more compartment space for tools and
equipment?
A.
B.
C.
D.
Midship pumps
Rear-mount pumps
Front-mount pumps
Power take-off driven fire pumps
9. Which pumps are powered by special fuels such as jet fuel?
A.
B.
C.
D.
Midship pumps
Front-mount pumps
Auxiliary engine-driven pumps
Power take-off driven fire pumps
_ _ 10. Which pumps are used on ARFF vehicles, wildand fire apparatus, and portable fire
pumps?
A.
B.
C.
D.
Midship pumps
Front-mount pumps
Auxiliary engine-driven pumps
Power take-off driven fire pumps
_ _ 11. Which pumps must be mounted correctly for dependable and smooth operation?
A.
B.
C.
D.
Midship pumps
Rear-mount pumps
Front-mount pumps
Power take-off driven fire pumps
_ _ 12. Which pumps are more susceptible to freezing in cold climates?
Pumping Apparatus Driver/Operator -
Lesson 10
37
A.
B.
C.
D.
Midship pumps
Front-mount pumps
Auxiliary engine-driven pumps
Power take-off driven fire pumps
_ _ 13. Which pumps are mounted between the front bumper and the grill?
A.
B.
C.
D.
Midship pumps
Front-mount pumps
Auxiliary engine-driven pumps
Power take-off driven fire pumps
_ _ 14. Which pumps require that the clutch be disengaged and the road transmission be placed in
neutral to prevent damage to the gears?
A.
B.
C.
D.
Midship pumps
Rear-mount pumps
Front-mount pumps
Power take-off driven fire pumps
_ _ 15. Which pumps are driven by a driveshaft that is connected to the PTO on the chassis
transmission?
A.
B.
C.
D.
Midship pumps
Front-mount pumps
Auxiliary engine-driven pumps
Power take-off driven fire pumps
_ _ 16. Which pumps are ideal for pump-and-roll operations?
A.
B.
C.
D.
Midship pumps
Front-mount pumps
Auxiliary engine-driven pumps
Power take-off driven fire pumps
_ _ 17. Which pumps offer the maximum amount of flexibility?
A.
B.
C.
D.
Midship pumps
Front-mount pumps
Auxiliary engine-driven pumps
Power take-off driven fire pumps
_ _ 18. Which pumps are mounted laterally across the frame behind the engine and transmission?
A.
B.
C.
D.
Midship pumps
Rear-mount pumps
Front-mount pumps
Power take-off driven fire pumps
Objective 9:
Answer questions about intake and discharge piping. Write the correct letters on the
blanks. (1 pt. each, 9/12)
_ _ 1. Which of the following is NOT a component of a piping system?
A. Impellers
B. Pump drains
Pumping Apparatus Driver/Operator -
Lesson 10
38
C. Intake piping
D. Discharge piping
___ 2. Which of the following is NOT a material used to construct piping systems?
A.
B.
C.
D.
Brass
Rubber
Cast iron
Stainless steel
_ _ 3. Piping systems must be able to withstand a hydrostatic test of_ psi (kPa) before being
placed into service.
A.
B.
C.
D.
350 psi (2 400 kPa)
400 psi (2 750 kPa)
450 psi (3 100 kPa)
500 psi (3 450 kPa)
_ _ 4. Piping that connects the pump and the onboard water tank is called:
A. intake piping.
B. tank fill lines.
C. booster lines.
D. discharge piping.
_ _ 5. Intake piping should be sized so that pumpers with a capacity of 500 gpm (1 900 Umin)
or less should be capable of flowing _ gpm (Umin) from the booster tank.
A.
B.
C.
D.
250 (950 Umin)
300 (1 150 Umin)
450 (1 700 Umin)
500 (1 900 Umin)
_ _ 6. Intake piping should be sized so that pumpers with a capacity greater than 500 gpm (1 900
Umin) should be capable of flowing at least _ gpm (Umin) from the booster tank.
A.
B.
C.
D.
500 gpm (1 900 Umin)
600 gpm (2 270 Umin)
800 gpm (3 050 Umin)
1,000 gpm (3 800 Umin)
_ _ 7. Intake piping may be as large as _
A.
B.
C.
D.
inches (mm) in diameter.
2 inches (50 mm)
3 inches (77 mm)
4 inches (100 mm)
5 inches (125 mm)
_ _ 8. Pumps that have a capacity of __ gpm (Umin) or greater may require more than one
large intake connection at each location.
A.
B.
C.
D.
1,000 gpm (3800 Umin)
1,500 gpm (6000 Umin)
2,000 gpm (7 600 Umin)
2,500 gpm (9 500 Umin)
_ _ 9. Apparatus with a rated pump capacity of750 gpm (2 850 Umin) or greater must be
equipped with at least _ 2Y.-inch (65 mm) discharge(s).
Pumping Apparatus Driver/Operator -
Lesson 10
39
A. one
B. two
C. three
D. four
_ _ 10. Apparatus with a rated pump capacity less than 750 gpm (2850 Llmin) are only required
to have _ 2Y:z-inch discharge(s).
A.
B.
C.
D.
one
two
three
four
_ _ 11. All discharge valves should be designed so that they are easily operable at pressures of up
to:
A. 100 psi (689 kPa).
B. 150 psi (1 035 kPa).
C. 200 psi (l 379 kPa).
D. 250 psi (l 724 kPa).
12. The tank fill line:
A. should be located on the intake side of the pump.
B. provides a means of replenishing the water carried in the tank.
C. prevents overheating by allowing water to be dumped into the tank or outside the tank
on the ground.
D. allows the tank to be filled without making any additional connections when the
pump is being supplied from an external supply source.
Objective 10:
Select facts about valves. Write the correct letters on the blanks. (1 pt. each, 6/8)
1. Valves control most of the _lines from the pump.
A. fill tank
B. waste/dump
C. booster cooling
D. intake and discharge
2. Valves must be:
A.
B.
C.
D.
airtight.
oil-free.
watertight.
made of rubber.
3. Which types of valves permit full flow through the lines with a minimum of friction loss?
A. Gate valves
B. Butterfly valves
C. Ball-type valves
D. Hydraulically, pneumatically, or electrically controlled valves
4. Which types of valves display readouts of how far the valve is opened?
A. Drain valves
Pumping Apparatus Driver/Operator - Lesson 10
40
B. Butterfly valves
C. Ball-type valves
D. Hydraulically, pneumatically, or electrically controlled valves
5. Which types of valves are most commonly used on large-diameter intakes and discharges?
A.
B.
C.
D.
Drain valves
Ball-type valves
Gate or butterfly valves
Hydraulically, pneumatically, or electrically controlled valves
6. Gate valves are most often operated by:
A.
B.
C.
D.
a handwheel.
push-pull handles.
electric actuators.
quarter-tum handles.
7. Butterfly valves are most often operated by:
A.
B.
C.
D.
a handwheel.
push-pull handles.
electric actuators.
quarter-tum handles.
8. Which types of valves indicate on the panel which direction to operate the switch in order
to open or close the valve?
A.
B.
C.
D.
Gate valves
Butterfl y valves
Ball-type valves
Hydraulically, pneumatically, or electrically controlled valves
Objective 11:
Distinguish between types of valve actuators. Write "PP" on the lines before
characteristics of push-pull handle actuators, and "QT" on the lines before characteristics of
quarter-turn handles. (1 pt. each, 8111)
_ _ I. Use a sliding gear-tooth rack that engages a sector gear connected to the valve stem
_ _ 2. Have a mechanical advantage due to the gear arrangement that makes it easier to operate
under pressure
3. Have a simpler mechanical linkage
4. Allow precise values of pressure to be set when adjusting individual lines
5. Have a handle mounted directly on the valve stem
_ _ 6. Are opened or closed by a 90-degree movement of the handle
7. Can be mounted in a location remote from the pump panel
8. Lock by rotating the handle in a clockwise direction
9. Some lock automatically when the handle is release, but the majority require a positive
action
Pumping Apparatus Driver/Operator -
Lesson 10
41
_ _ 10. Have a flat handle that can be used to lock the valve in any position by a 90-degree twist
of the handle
_ _ 11. Must be pulled straight-out, in a level manner
Objective 12:
List purposes of drain valves and bleeder lines. (1 pI. each, 3/5)
Drain valves
1.
2.
3.
Bleeder lines
I.
2.
Objective 13:
Identify characteristics of various automatic pressure control devices. Write the
correct letters on the blanks. (1 pt. each, 10/13)
_ _ I. Automatic pressure control devices must operate within _
pressure rises.
seconds after the discharge
A. 2 to 5
B. 3 to 10
C. 4to 10
D. 5 to 15
_ _ 2. Automatic pressure control devices must not allow the pressure to exceed _
above the set level.
A.
B.
C.
D.
psi (kPa)
10 psi (70 kPa)
20 psi (140 kPa)
30 psi (200 kPa)
40 psi (280 kPa)
3. Which types of automatic pressure control devices are sensitive to pressure change and
have the ability to relieve excessive pressure within the pump discharge?
A.
B.
C.
D.
Pressure governors
Electronic governors
Intake pressure relief valves
Discharge pressure relief valves
4. Which types of automatic pressure control devices regulate pressure on centrifugal
pumps?
A. Pressure governors
Pumping Apparatus Driver/Operator -
Lesson 10
42
B. Electronic governors
C. Intake pressure relief valves
D. Discharge pressure relief valves
5. Which types of automatic pressure control devices are intended to reduce the possibility of
damage to the pump and discharge hose lines caused by water hammer?
A.
B.
C.
D.
Pressure governors
Electronic governors
Intake pressure relief valves
Discharge pressure relief valves
6. Which types of automatic pressure control devices are quick to react to overpressure
conditions, but are somewhat slower to reset back to "all-closed" positions?
A.
B.
C.
D.
Pressure governors
Electronic governors
Intake pressure relief valves
Discharge pressure relief valves
7. Which types of automatic pressure control devices fit onto the carburetor or throttle link
and reduces or increases the engine speed under the control of a rod connected to a piston
in a water chamber?
A.
B.
C.
D.
Pressure governors
Electronic governors
Piston assembly governors
Discharge pressure relief valves
8. Which types of automatic pressure control devices may be attached to either a regular or
an auxiliary throttle?
A.
B.
C.
D.
Pressure governors
Electronic governors
Piston assembly governors
Discharge pressure relief valves
9. Which types of automatic pressure control devices take a short time for the pump to return
to normal operation?
A.
B.
C.
D.
Pressure governors
Electronic governors
Piston assembly governors
Discharge pressure relief valves
_ _ 10. Which types of automatic pressure control devices should be set to open when the intake
pressure rises more than 10 psi (70 kPa) above the desired operating pressure?
A.
B.
C.
D.
Pressure governors
Electronic governors
Piston assembly governors
Intake pressure relief valves
_ _ 11. Which types of automatic pressure control devices use a pressure-sensing element
connected to the discharge manifold to control the action of an electronic pump amplifier
that compares pump pressure to an electrical reference point?
Pumping Apparatus Driver/Operator - Lesson 10
43
A.
B.
C.
D.
Pressure governors
Electronic governors
Piston assembly governors
Intake pressure relief valves
_ _ 12. Which types of automatic pressure control devices relieve excess pressure that is generally
caused by shutting down one or more operating hoselines?
A.
B.
C.
D.
Pressure governors
Electronic governors
Piston assembly governors
Intake pressure relief valves
_ _ 13. Which types of automatic pressure control devices have an adjustable spring-loaded pilot
valve that actuates the relief valve to bypass water from the discharge 10 the intake
chamber of the pump?
A.
B.
C.
D.
Pressure governors
Electronic governors
Intake pressure relief valves
Discharge pressure relief valves
Objective 14:
Match pump primers to their descriptions and operating techniques. Write the correct
letters on the blanks. Letters may be used more than once. (1 pt. each, 14119)
1. Do not discharge oil in the primary process
_ _ 2. Are the simplest type of primer
3. May be rotary vane or rotary gear type
4. Work best at low engine rpm
5. Are not very efficient and require a great deal of
A. Positive displacement
primers
B. Oil-less primers
C. Exhaust primers
D. Vacuum primers
maintenance
6. Have an inlet connected to a primer control
valve that is in turn connected to the fire pump
7. Were common on older, gasoline-powered fire
apparatus
8. Use an oil supply or some other type of fluid to
seal the gaps between the gears and the case and
to act as a preservative and minimize
deterioration
9. Are environmentally friendly
10. May be driven off the transfer case of the
transmission or may be electric-driven
_ _ 11. Are constructed of space-age materials that do
not require lubrication
_ _ 12. Require high engine rpm to operate
Pumping Apparatus Driver/Operator -
Lesson 10
44
_ _ 13. May be installed on new apparatus or in
apparatus that came with conventional oillubricated primers as original equipment
_ _ 14. Are still found on many skid-mounted pumps
and some older pieces of apparatus
_ _ 15. Operate on the same principle as a foam eductor
_ _ 16. Can draw water through the pump and into the
intake manifold, causing damage to the engine;
can be prevented with a eheck valve
17. Are the most common choice of manufacturers
and fire departments
_ _ 18. Require that any air leaks in the pump be kept to
an absolute minimum and that suction hose and
gaskets be kept in good condition
_ _ 19. Prime the pump by connecting a line from the
intake manifold of the engine to the intake of
the fire pump with a valve connected in the line
to control it
Objective 15:
Match pump panel controls and instruments to their descriptions. Write the correct
letters on the blanks. (1 pt. each, 8111)
I. Provides an indication of the vacuum present at the
intake of the pump during priming or when the pump is
operating from draft
A. Master intake gauge
(vacuum or compound
gauge)
2. Registers the pressure as it leaves the pump, but before
it reaches the gauges for each individual discharge line
B. Master pump discharge
pressure gauge
C. Primer control
D. Pump overheat indicator
E. Pump pressure indicators
(discharge gauges)
F. Pumping engine coolant
temperature indicator
G. Pumping engine oil pressure
indicator
H. Pumping engine throttle
L Tachometer
J. Voltmeter
K. Water tank level indicator
3. Records the engine speed in rpm
_ _ 4. Shows the temperature of the coolant in the engine that
powers the fire pump
_ _ 5. Shows that an adequate supply of oil is being delivered
to the critical areas of the engine that is powering the
fire pump
6. Warns the driver/operator when the pump overheats
7. Provides a relative indication of battery condition and
alternator output
8. Indicate actual pressure applied to hoselines
9. Is used to increase or decrease the speed of the engine
that is powering the fire pump
_ _ 10. Is used to operate the priming device when the pump is
going to be used to draft from a static water supply
Pumping Apparatus Driver/Operator -
Lesson 10
45
_ _ II. Is intended to let the driver/operator know how much
water is remaining in the onboard water tank
Objective 16:
State the primary function of an auxiliary cooler. (2 pts., 212)
Objective 17:
Explain the operation of marine- and immersion-type auxiliary coolers. (2 pts. each,
214)
I. Marine-type _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
2. Immersion-type,_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
Pumping Apparatus Driver/Operator -
Lesson 10
46
Pumping Apparatus Driver/Operator
Lesson 10 -
Fire Pump Theory
Written Test Answers
Objective 1
I.D
2. B
3.
4.
5.
6.
7.
8.
9.
10.
B
C
D
B
A
D
C
A
Objective 2
Piston pumps
1. intake; discharge
2. air
3. forward
4. increases; decreases; suction hose
5. reduced
6. primed
Rotary gear pumps
I. two
2. watertight; airtight
3. discharge
4. tooth
Rotary vane pumps
1. rotor; housing
2. centrifugal force
3. worn
4. air
5. smaller
6. maximum
7. reduced
8. primed
Objective 3
I.D
2. A
3. C
4. A
Pumping Apparatus Driver/Operator -
Lesson 10
47
S.
6.
7.
8.
B
D
B
C
Objectivc 4
1. outer edge
2. pressure
3. upward
4. rotation
5. energy; pressure
Objective 5
1. C
2. B
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
D
A
A
C
B
B
A
D
A
B
Objective 6
l.A
2.
3.
4.
5.
D
C
D
D
Objective 7
l.A
2. D
3. D
C
B
A
B
A
D
4.
5.
6.
7.
8.
9.
10.
B
Objective 8
I.e
2. A
3. B
Pumping Apparatus Driver/Operator -
Lesson 10
48
4.
5.
6.
7.
D
A
B
A
8. B
9.
10.
II.
12.
13.
14.
15.
16.
17.
18.
C
C
D
B
B
A
D
C
C
A
Objective 9
l.A
2. B
3. D
4. A
5. A
6. A
7. C
8. B
9. B
10. A
II. D
12. D
Objective 10
I.D
2. A
3. C
4. D
5. C
6. A
7. D
8. D
Objective 11
I. PP
2. PP
3. QT
4. PP
5. QT
6. QT
7. PP
8. QT
Pumping Apparatus Driver/Operator -
Lesson 10
49
9. QT
10. PP
II. PP
Objective 12
Answers should include any three of the following:
Drain valves
• Provide a way for the driver/operator to relieve the pressure from the hoseline after the discharge
valve and nozzle have both been closed
• Allow for draining and disconnecting unused lines even when the pump is still in service
• Remove water from the system in climates where freezing might occur
Bleeder lines
• Allow air to be removed from system before it enters fire pump
• Make it possible to change over to the supply line without interrupting fire streams
Objective 13
I. B
2. C
3. D
4. A
5. C
6. D
7. C
8. A
9. D
10. D
11. B
12. A
l3.D
Objective 14
I. B
2. D
3. A
4. D
5. C
6. A
7. D
8. A
9. B
10. A
11. B
12. C
13. B
14. C
15. C
16. D
17. A
18. C
19. D
Pumping Apparatus Driver/Operator -
Lesson 10
50
Objective 15
l.A
2. B
3.
4.
5.
6.
7.
8.
9.
10.
I
F
G
D
J
E
H
C
II. K
Objective 16
• To control the temperature of coolant in the apparatus engine during pumping operations
Objective 17
Marine-type - Is inserted into one of the hoses used in the engine cooling system so that the engine
coolant must travel through it as it circulates through the system
Immersion-type - The water being supplied by the fire pump passes through a coil or some type of
tubing mounted inside the cooler so that it is immersed in the coolant.
Pumping Apparatus Driver/Operator -
Lesson 10
51
Pumping Apparatus Driver/Operator
Lesson 10 -
Fire Pump Theory
Competency Profile
Student Name _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ID # _ _ _ _ _ _ __
Organization _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
Instructor's Name _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
Session Dates _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
Instructor's Directions:
1. Check the student's competency rating for each assignment sheet, and skill sheet listed below.
2. List any additional assignment sheets or skills under "Other," and check the student's competency
rating.
3. Record the student's written test scores in the spaces provided.
. PASS/FAIL
ASSIGNMENT SHEETS
None required
Other _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ____
'PASS/FAIL
,
.
SKILL SHEETS
None required
Other _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ____
POINTS
ACHIEVED
POINTS
NEEDED/
TOTAL
WRITIEN TEST
7/10
I. Select facts about positive displacement pumps.
14/18
2. Complete statements about the operation of positive displacement
fire pumps.
618
3. Answer questions about centrifugal pumps.
Pumping Apparatus Driver/Operator -
Lesson 10
52
--
-----
----
3/5
4. Complete statements about the operation of centrifugal pumps.
10/12
5. Match centrifugal pumps to their characteristics.
4/5
6. Answer questions about changeover.
7/10
7. Select facts about pump wear rings and packing rings.
13118
8. Identify characteristics of pump mounting and drive arrangements.
9112
9. Answer questions about intake and discharge piping.
6/8
10. Select facts about valves.
8/11
II. Distinguish between types of valve actuators.
3/5
12. List purposes of drain valves and bleeder lines.
10113
13. Identify characteristics of various automatic pressure control
devices.
14119
14. Match pump primers to their descriptions and operating techniques.
8111
15. Match pump panel controls and instruments to their descriptions.
2/2
16. State the primary function of an auxiliary cooler.
2/4
17. Explain the operation of marine- and immersion-type auxiliary
coolers.
Pumping Apparatus Driver/Operator -
Lesson 10
53