Pumping Apparatus
Driver/Operator — Lesson 11
Pumping Apparatus Driver/Operator
Handbook, 2nd Edition
Chapter 11 — Operating Fire Pumps
Learning Objectives
1. Answer questions about making the pump
operational.
2. Engage and disengage a power take-off
(PTO) or front-mount pump during pumpand-roll operation.
3. Engage and disengage a power take-off
(PTO) or front-mount pump during
stationary operation.
(Continued)
Pumping Apparatus
Driver/Operator
11–1
Learning Objectives
4. Engage and disengage a midship pump.
5. Engage and disengage an auxiliary engine
driven fire pump.
6. Complete statements about operating from
the water tank.
7. Operate from the apparatus water tank.
(Continued)
Pumping Apparatus
Driver/Operator
11–2
Learning Objectives
8. Make the transition from the apparatus
water tank to an external water supply.
9. Answer questions about operating from a
pressurized water supply source.
10. Operate from a pressurized water source.
11. Select facts about choosing a hydrant.
Pumping Apparatus
Driver/Operator
11–3
(Continued)
Learning Objectives
12. Describe both a forward lay and a reverse
lay.
13. Answer questions about forward and
reverse lays.
14. List the preliminary checks that should be
made after making hydrant connections but
before opening the hydrant.
(Continued)
Pumping Apparatus
Driver/Operator
11–4
Learning Objectives
15. Answer questions about putting the pump
in service.
16. List methods for preventing pump
overheating.
17. Complete statements about determining
how much additional water a hydrant can
supply.
(Continued)
Pumping Apparatus
Driver/Operator
11–5
Learning Objectives
18. Calculate how much additional water a
hydrant can supply.
19. List the steps for shutting down the hydrant
operation.
20. Answer questions about operating from a
static water supply source.
(Continued)
Pumping Apparatus
Driver/Operator
11–6
Learning Objectives
21. List indications that a pump is cavitating.
22. Select facts about selecting the drafting
site.
23. Select facts about connecting to the pump.
24. Answer questions about priming the pump
and beginning operation.
(Continued)
Pumping Apparatus
Driver/Operator
11–7
Learning Objectives
25. List common causes of inability to prime
the pump.
26. List the categories of problems that can
occur while operating from draft.
27. Operate from a static water source.
28. Select facts about supporting automatic
sprinkler systems.
(Continued)
Pumping Apparatus
Driver/Operator
11–8
Learning Objectives
29. Support a sprinkler system.
30. Select facts about supporting standpipe
systems.
31. List factors that determine pump discharge
pressure when supporting standpipe FDCs.
(Continued)
Pumping Apparatus
Driver/Operator
11–9
Learning Objectives
32. Explain techniques for overcoming various
standpipe impairments.
33. Support a standpipe system.
34. Troubleshoot pumping operations.
Pumping Apparatus
Driver/Operator
11–10
Making the Fire Pump Operational
• Is also referred to as “putting the pump into
gear”
• Begins after the apparatus has been properly
positioned and the parking brake has been
set
(Continued)
Pumping Apparatus
Driver/Operator
11–11
Making the Fire Pump Operational
• After properly positioning the apparatus and
setting the parking brake, on the majority of
apparatus, the remainder of the procedure for
making the fire pump operational takes place
before the driver/operator exits the cab.
(Continued)
Pumping Apparatus
Driver/Operator
11–12
Making the Fire Pump Operational
• Once the driver/operator exits the cab, in all
cases except when the apparatus is used for
pump-and-roll operations, the next step
should be to chock the apparatus wheels.
(Continued)
Pumping Apparatus
Driver/Operator
11–13
Making the Fire Pump Operational
• IFSTA recommends
that the apparatus
wheels be chocked
every time the
apparatus is
stopped with the
engine running and
the driver/operator
exits the cab.
Pumping Apparatus
Driver/Operator
11–14
Operating from the Water Tank
• Most driver/operators operate solely from the
onboard water tank at the vast majority of
incidents.
• In some circumstances, the fire attack begins
with the water tank and may then make the
transition to an external supply source.
(Continued)
Pumping Apparatus
Driver/Operator
11–15
Operating from the Water Tank
• The pump operator must be able to make the
transition from the apparatus tank to an
incoming water supply smoothly, with no
disruption of the fireground operation.
Pumping Apparatus
Driver/Operator
11–16
Operating from a Pressurized
Water Supply Source
• Two basic pressurized water supply sources
used to supply a fire pump
– Hydrant
– A supply hose from another fire pump
Pumping Apparatus
Driver/Operator
11–17
Negative Pump Pressure
(Vacuum)
• Water enters the pump under pressure.
• As the discharge pressure or volume from the
fire pump increases, the incoming pressure
from the supply source may drop due to
friction loss in the water system.
• If the discharge pressure is increased too
much, the intake pressure from the supply
source may be reduced below 0 psi (0 kPa).
Pumping Apparatus
Driver/Operator
11–18
Dangers of Operating at Negative
Pressure from a Fire Hydrant
• Increases the possibility of damage to the fire
pump due to cavitation
• Can cause damage to the pump and water
system due to water hammer if the flow is
stopped suddenly
• May damage water heaters or other domestic
appliances on a municipal water supply
system
Pumping Apparatus
Driver/Operator
11–19
Dangers of Operating at Negative
Pressure from Another Pumper
• Can cause supply hose to collapse, resulting
in interruption of water supply
• Can damage the pump through cavitation
Pumping Apparatus
Driver/Operator
11–20
Choosing a Hydrant
• A thorough knowledge of the water system is
required.
• The hydrants are located on large water
mains that are interconnected in a grid
pattern.
• The worst are those located on “dead-end
mains.”
(Continued)
Pumping Apparatus
Driver/Operator
11–21
Choosing a Hydrant
• Single mains that supply small amounts of
water do not have sufficient flow to prevent
them from becoming clogged with sediment
and encrustation.
• Fire departments should have access to
water department records that indicate the
reliability of all hydrants in their jurisdiction.
(Continued)
Pumping Apparatus
Driver/Operator
11–22
Choosing a Hydrant
• Apparatus may be equipped with map books
with hydrant information and locations.
• Fire hydrants may be color coded to indicate
the flow that can be expected.
• Once a hydrant is selected, the pumper
should be hooked to it as quickly as possible,
using a forward or reverse lay.
Pumping Apparatus
Driver/Operator
11–23
Forward Lay
• Stop at the hydrant, drop the end of one or
more supply lines at the hydrant, and proceed
to the fire location.
(Continued)
Pumping Apparatus
Driver/Operator
11–24
Forward Lay
• Problems
– The distance from the hydrant to the fire
and the length of hose carried on the
engine. If the first-arriving engine runs out
of hose, it may be necessary to bring in
more hose or have the next-arriving
company set up a relay pumping operation.
(Continued)
Pumping Apparatus
Driver/Operator
11–25
Forward Lay
• May use a four-way hydrant valve
– Allows the original supply line to be
immediately charged with hydrant pressure
– Has second discharge outlet that allows
second pumper to connect to hydrant without
interrupting flow to original supply line
– Allows the pumper connecting to the valve to
boost pressure in the original supply line
(Continued)
Pumping Apparatus
Driver/Operator
11–26
Forward Lay
(Continued)
Pumping Apparatus
Driver/Operator
11–27
Forward Lay
• Gate valves should be attached to unused
hydrant discharges when using dry-barrel
hydrants.
• When using 2½- or 3-inch (65 mm or 77 mm)
hoselines to supply the pumper off hydrant
pressure, it is recommended that the lines be
no longer than 300 feet (90 m)
Pumping Apparatus
Driver/Operator
11–28
Reverse Lay
• Lays hose from the fire to the water source
• Is used when a pumper must first go to the
fire location for size-up
• Is the most expedient way to lay hose if the
apparatus must stay at the water source
(Continued)
Pumping Apparatus
Driver/Operator
11–29
Reverse Lay
(Continued)
Pumping Apparatus
Driver/Operator
11–30
Reverse Lay
• Requires that, if threaded couplings are used,
hose beds should be loaded so that the first
coupling to come off is male
• Is standard for setting up a relay pumping
operation when using smaller diameter hose
as a supply line
(Continued)
Pumping Apparatus
Driver/Operator
11–31
Reverse Lay
• Disadvantages
– Essential fire fighting equipment must be
removed and placed at the fire location
before the pumper can proceed to the
water source, causing delays
– Pumper may not carry enough hose to
reach from the fire to the nearest water
source
(Continued)
Pumping Apparatus
Driver/Operator
11–32
Reverse Lay
• Does not require a four-way hydrant valve,
although one can be used
• May be used when the first pumper arrives at
a fire and must work alone for an extended
period of time
Pumping Apparatus
Driver/Operator
11–33
After Making Hydrant Connections
but Before Opening the Hydrant
• Check that:
– The tank–to-pump valve must be closed if
the intake is not equipped with a shutoff
valve
– A dry barrel hydrant must be opened all the
way
(Continued)
Pumping Apparatus
Driver/Operator
11–34
After Making Hydrant Connections
but Before Opening the Hydrant
• After the pump is full of water and the
pressure in the system has stabilized with no
water flowing, a reading of the pressure on
the master intake gauge indicates the static
pressure in the water supply system.
(Continued)
Pumping Apparatus
Driver/Operator
11–35
After Making Hydrant Connections
but Before Opening the Hydrant
• It may be desirable for the pump operator to
record or remember the static pressure
before the operation begins.
• Some departments use a grease pencil to
mark the static pressure on the intake gauge.
Pumping Apparatus
Driver/Operator
11–36
Putting the Pump in Service
• Do not engage the pump drive system before
leaving the cab if there will be an extended
period of time where water is introduced into
the pump.
• On a two-stage pump, set the transfer valve
to the proper position before increasing the
throttle to build discharge pressure.
• Open discharge valves slowly.
Pumping Apparatus
Driver/Operator
11–37
Preventing Pump Overheating
• Pull some of the booster line off the reel and
securely tie off the nozzle to a solid object.
Open the valve that supplies the booster reel,
and discharge water in a direction that will not
harm people or damage property.
(Continued)
Pumping Apparatus
Driver/Operator
11–38
Preventing Pump Overheating
• Open a discharge drain valve.
– Designed to discharge water in a manner that
will not harm people or damage property
– May have threaded outlets that allow hose to be
connected and routed to a safe discharge point
– If so, discharge water away from the apparatus
so that it does not become stuck in the mud (or
frozen in ice) that could be created by
discharging water directly beneath it
(Continued)
Pumping Apparatus
Driver/Operator
11–39
Preventing Pump Overheating
• Partially open the tank fill valve or pump-totank line.
• Use a bypass or circulator valve if the
apparatus is so equipped.
Pumping Apparatus
Driver/Operator
11–40
Determining How Much Additional
Water a Hydrant Can Supply
• When a pumper is connected to a hydrant
and is not discharging water, the pressure
shown on the intake gauge is static pressure.
• When the pumper is discharging water, the
intake gauge reading is the residual pressure.
• The difference between these two pressures
is used to determine how much more water
the hydrant can supply.
Pumping Apparatus
Driver/Operator
11–41
Percentage Method
• Calculate the drop in pressure as a
percentage, using the following formula:
Percent drop = (Static – Residual)(100)
Static
(Continued)
Pumping Apparatus
Driver/Operator
11–42
Percentage Method
• 10% or less – May add 3 lines with same flow
as the line being used
• 11 to 15% – May add 2 lines with same flow
as the line being used
• 16 to 25% – May add 1 line with same flow as
the line being used
• Over 25% – More water may be available,
but not as much as is flowing through the line
being used
Pumping Apparatus
Driver/Operator
11–43
First-Digit Method
• Find the difference in psi between the static
and residual pressures.
• Multiply the first digit of the static pressure by
1, 2, or 3 to determine how many additional
lines of equal flow may be added.
(Continued)
Pumping Apparatus
Driver/Operator
11–44
First-Digit Method
• If psi drop is equal to or less than the first digit
of the static pressure multiplied by:
– one (1), three additional lines of equal flow
may be added
– two (2), two additional lines of equal flow
may be added
– three (3), one additional line of equal flow
may be added
Pumping Apparatus
Driver/Operator
11–45
Squaring the Lines Method
• Note the static pressure on the water system
before any pump discharges are open.
• Figure a relatively close figure of the volume
of water that is initially being flowed by the
pumper.
• Square the number of lines currently flowing
and multiply by the original pressure drop.
Pumping Apparatus
Driver/Operator
11–46
Shutting Down the
Hydrant Operation
1. Gradually slow the engine rpm to idle to
reduce the discharge pressure.
2. Take the pressure control device out of
service if in use.
3. Slowly and smoothly close the discharge
valves.
4. Place the drive transmission in neutral, and
disengage the pump control device.
Pumping Apparatus
Driver/Operator
11–47
Operating from a Static
Water Supply Source
• In most cases, pumpers will be pumping
water from a static water supply that will be
located at a lower level than the fire pump.
• Because one drop of water will not stick to
another, it is not possible to pull water into the
pump from a lower level.
(Continued)
Pumping Apparatus
Driver/Operator
11–48
Operating from a Static
Water Supply Source
• To pump from a lower level, a pressure
differential (partial vacuum) must be created
by evacuating some of the air inside the fire
pump.
• To accomplish this, an airtight, noncollapsible
waterway (hard intake hose) is needed
between the pump and the body of water to
be used.
(Continued)
Pumping Apparatus
Driver/Operator
11–49
Operating from a Static
Water Supply Source
• The amount of friction loss in the hard intake
hose is dependent upon the diameter and
length of the hose.
• The total pressure available to overcome all
these pressure losses is limited to the
atmospheric pressure at sea level – 14.7 psi
or 100 kPa.
(Continued)
Pumping Apparatus
Driver/Operator
11–50
Operating from a Static
Water Supply Source
• Atmospheric pressure decreases 0.5 psi
(3.5 kPa) for each 1,000 feet (305 m) of
elevation gain.
• Increasing the height of the lift decreases
total pump capacity.
(Continued)
Pumping Apparatus
Driver/Operator
11–51
Operating from a Static
Water Supply Source
• The maximum amount of vacuum that most
pumps develop is around 22 inches (560 mm)
or mercury. A reading anywhere near this is a
warning that the pump is getting close to the
limit of its ability.
Pumping Apparatus
Driver/Operator
11–52
Cavitation
• Is the condition where water is being
discharged from the pump faster than it is
coming in
• Results if an attempt is made to increase the
discharge from the pump beyond the point of
maximum vacuum on the intake
• Can damage the pump
Pumping Apparatus
Driver/Operator
11–53
Indications of Cavitation
• Hose streams will pulsate, and the pressure
gauge on the pump will fluctuate
• A popping or sputtering may be heard as the
water leaves the nozzle
• The pump will be noisy, sounding like gravel
is passing through it
• A lack of reaction on the pressure gauge to
changes in the setting of the throttle
Pumping Apparatus
Driver/Operator
11–54
Selecting a Drafting Site
• If a draft is being established to supply water
tenders for a shuttle operation, there may be
several choices.
• The choice is dictated by:
– Amount of water (the most important
factor)
– Type of water
– Accessibility of water
Pumping Apparatus
Driver/Operator
11–55
Amount of Water Available
• If using a traditional
strainer, there
should be a
minimum of 2 feet
(0.6 m) all around
the strainer
(Continued)
Pumping Apparatus
Driver/Operator
11–56
Amount of Water Available
• If using a traditional
strainer, a whirlpool can
form if there are not 2
feet (0.6 m) above the
strainer.
– Place a wooden
board, capped plastic
bottle, or beach ball
above strainer to
prevent whirlpool.
Pumping Apparatus
Driver/Operator
11–57
(Continued)
Amount of Water Available
• Drafting from a swiftly
moving shallow stream
– A dam can be
constructed,
– The bottom can be
dug out to form a
pool,
– Or a combination of
both
(Continued)
Pumping Apparatus
Driver/Operator
11–58
Amount of Water Available
• Drafting from a swiftly moving shallow stream
– A “floating” strainer can be used – the end of intake
hose floats on surface, and water is drawn into
intake hose through holes on bottom of strainer
(Continued)
Pumping Apparatus
Driver/Operator
11–59
Amount of Water Available
• Drafting from a portable water tank or
swimming pool
– A low-level strainer may be used, which
sits directly on the bottom of the tank or
pool and allows the water to be drafted
down to a depth of about 2 inches (50 mm)
(Continued)
Pumping Apparatus
Driver/Operator
11–60
Amount of Water Available
• Drafting from the ocean
– What may be an acceptable drafting
location at one time of the day may not be
usable when the tide goes out
• Temperature of water
– Water below 35ºF (2ºC) or above 90ºF
(32ºC) may adversely impact the pump’s
ability to reach capacity
Pumping Apparatus
Driver/Operator
11–61
Type of Water Available
• Any type of water can be used; however:
– Untreated water can be harmful
– Salt water and caustic chemicals can
cause corrosion of the pump
– Foreign materials and debris can clog the
strainer
• The most common type of contamination, and
the most damaging, is dirty or sandy water.
Pumping Apparatus
Driver/Operator
11–62
Accessibility of Water
• A maximum atmospheric pressure of 14.7 psi
(100 kPa) is available when drafting. This
pressure has to overcome elevation pressure
and friction loss.
• As the amount of lift increases:
– Elevation pressure increases
– Less friction loss can be overcome
– Capacity of the pump is decreased
(Continued)
Pumping Apparatus
Driver/Operator
11–63
Accessibility of Water
• All fire pumps are rated to pump their
•
•
•
•
•
capacity at 10 feet (3 m) of lift.
Less lift, higher capacity; greater lift, the
capacity decreases.
Stability of ground
Time of year
Convenience of connecting hoselines
Safety of the operator
Pumping Apparatus
Driver/Operator
11–64
Connecting to the Pump
• The apparatus may be able to park directly at
the drafting location, or may have to
temporarily park short.
• Once the hard intake hose and strainer are
connected to the apparatus, they can be put
into the desired position and the apparatus
can then ease slowly into the final drafting
spot.
(Continued)
Pumping Apparatus
Driver/Operator
11–65
Connecting to the Pump
• Before connecting sections of hard intake
hose, check that the gaskets are in place and
that couplings are free of dirt or gravel.
• The strainer and hard intake hose must be
coupled and made airtight.
(Continued)
Pumping Apparatus
Driver/Operator
11–66
Connecting to the Pump
• It is usually easiest to connect the hose to the
intake fittings by first putting the strainer in the
water and then pulling the apparatus into
position.
• Improper positioning of the hard intake hose
can result in the formation of an air pocket
that can prevent effective drafting.
(Continued)
Pumping Apparatus
Driver/Operator
11–67
Connecting to the Pump
• If a barrel strainer is used, the rope that was
tied to it can be used to suspend the strainer
above the bottom by tying it to the pumper or
to a tree or other fixed object.
(Continued)
Pumping Apparatus
Driver/Operator
11–68
Connecting to the Pump
• If the bottom slopes away steeply from the
edge, it may be possible to put a roof ladder in
the water and rest the intake hose on it.
Pumping Apparatus
Driver/Operator
11–69
Priming the Pump and
Beginning Operation
• Starts the draft operation
• Transfer valve on two-stage pumps must be
in the PARALLEL (VOLUME) position
• All drains and valves must be closed
• All unused openings must be capped to make
the pump airtight before beginning
Pumping Apparatus
Driver/Operator
11–70
(Continued)
Priming the Pump and
Beginning Operation
• On a positive displacement pump that is
driven by the transfer case, the engine rpm
should be set according to manufacturer’s
instructions.
• Most priming pumps are intended to work
best between 1,000 and 1,200 rpm.
(Continued)
Pumping Apparatus
Driver/Operator
11–71
Priming the Pump and
Beginning Operation
• When operating the primer control, the
vacuum reading on the master intake gauge
should read 1 inch (25 mm) for each 1 foot
(0.3 m) of lift.
• Priming should not be stopped until all air has
been removed and primer is discharging a
steady stream of water.
(Continued)
Pumping Apparatus
Driver/Operator
11–72
Priming the Pump and
Beginning Operation
• The entire action typically requires 10 to 15
seconds, but should not take more than 30
seconds.
• If a prime has not been achieved in 30
seconds, stop priming and find out what the
problem is.
(Continued)
Pumping Apparatus
Driver/Operator
11–73
Priming the Pump and
Beginning Operation
• Causes of inability to prime:
– An air leak that prevents the primer from
developing enough vacuum to successfully
draft water
– Insufficient fluid in the priming reservoir
– Engine speed (rpm) is too slow
– Lift is too high
– A high point in the hard intake hose is
creating an air pocket
(Continued)
Pumping Apparatus
Driver/Operator
11–74
Priming the Pump and
Beginning Operation
• After successful priming, slowly increase
throttle before opening any discharges. The
pressure should be between 50 and 100 psi
(350 kPa and 700 kPa).
(Continued)
Pumping Apparatus
Driver/Operator
11–75
Priming the Pump and
Beginning Operation
• Open discharge valves slowly while
observing discharge pressure.
– If pressure falls below 50 psi (350 kPa),
pause to allow it to stabilize.
– If pressure continues to drop, momentarily
operate primer to eliminate air in the pump
and restore pressure to original value.
(Continued)
Pumping Apparatus
Driver/Operator
11–76
Priming the Pump and
Beginning Operation
• Constant movement of water through the
pump prevents overheating and maintains a
vacuum.
Pumping Apparatus
Driver/Operator
11–77
Operating the Pump from Draft
• Is the most demanding type of operation
• Demands careful monitoring of gauges
associated with the engine as well as those
associated with the pump; any deviation from
normal engine temperature is a signal that
another pumper should be used
Pumping Apparatus
Driver/Operator
11–78
Problems that Can Occur
While Operating from Draft
• Air leak on the intake side of the pump
• Whirlpool allowing air to enter the pump
• Air leakage due to defective packing in the
pump
Pumping Apparatus
Driver/Operator
11–79
Shutting Down the Operation
• Slowly decrease the engine speed to idle
• Take the pump out of gear
• Allow the pump to drain
• Operate the primer until primer oil or fluid
comes out of the discharge from the priming
pump
Pumping Apparatus
Driver/Operator
11–80
Supporting Automatic
Sprinkler Systems
• Because fires rarely cause all the sprinklers
in a building to open, the water supply for
sprinkler systems is designed to supply only a
fraction of the total number of sprinklers
installed on the system.
(Continued)
Pumping Apparatus
Driver/Operator
11–81
Supporting Automatic
Sprinkler Systems
• Upon arrival, supply the fire department
connection (FDC) immediately.
– A siamese with at least two 2 ½-inch (65
mm) female connections, or
– One large diameter sexless connection
connected to a clappered inlet
(Continued)
Pumping Apparatus
Driver/Operator
11–82
Supporting Automatic
Sprinkler Systems
• If any indication of actual fire
– A minimum of two 2 ½-inch (65 mm)
hoselines should be connected to the FDC
– Supply lines should be laid to the hydrant
and connections made
• Rule of thumb: One 1,000 gpm (4 000 L/min)
rated pumper should supply the FDC for
every 50 sprinklers estimated to be flowing.
(Continued)
Pumping Apparatus
Driver/Operator
11–83
Supporting Automatic
Sprinkler Systems
CAUTION! When interior crews are operating
hoselines from a combination
sprinkler/standpipe system with sprinklers
flowing, the pressure supplied to the FDC
should be based on the safe operating
pressure for the hose crews.
(Continued)
Pumping Apparatus
Driver/Operator
11–84
Supporting Automatic
Sprinkler Systems
• Interior attack crews should locate fire and
determine if charging sprinkler system is
necessary. If so, driver/operator should slowly
develop pressure needed to supply system.
• Recommended pressures may be:
– Listed on a plate at the FDC
– Listed in pre-incident plans
– Rule of thumb: 150 psi (1 050 kPa)
(Continued)
Pumping Apparatus
Driver/Operator
11–85
Supporting Automatic
Sprinkler Systems
• When possible, a firefighter should
immediately check the control valves to
ensure that they are open.
• If a fixed fire pump on the property supplies
the sprinkler system, the firefighter should
also ensure that the pump is running.
Pumping Apparatus
Driver/Operator
11–86
Standpipe Systems
• Are used to speed fire attack in multistory or
single-story buildings with large floor areas
• Include 2½- or 1½-inch (65 mm or 38 mm)
connections on each floor
(Continued)
Pumping Apparatus
Driver/Operator
11–87
Standpipe Systems
Note: Fire personnel should not use house or
standpipe lines unless a hose-testing
program is implemented.
(Continued)
Pumping Apparatus
Driver/Operator
11–88
Standpipe Systems
• May be wet or dry
– Wet: Contain water under pressure
– Dry: Must be supplied with water from the
FDC outside the building
Note: Standpipe FDCs should be clearly
marked to prevent confusion between
sprinkler and standpipe connections.
(Continued)
Pumping Apparatus
Driver/Operator
11–89
Standpipe Systems
• Pump discharge pressure depends on:
– Pressure loss (25 psi [150 kPa]) in the
standpipe
– Friction loss in the hose from the pumper
to the FDC
– Friction loss in the hose on the fire floor
– Nozzle pressure for type of nozzle used
– Elevation pressure due to the height of the
building
(Continued)
Pumping Apparatus
Driver/Operator
11–90
Standpipe Systems
• When calculating discharge pressure, add 5
psi (35 kPa) to nozzle pressure for each floor
above standpipe connection that will have
operating fire streams in addition to losses
already mentioned.
(Continued)
Pumping Apparatus
Driver/Operator
11–91
Standpipe Systems
• Pump discharge pressure calculations are too
lengthy to make at scene
• Fire department should have a planned pump
discharge pressure or develop a rule of
thumb for each building in the area.
(Continued)
Pumping Apparatus
Driver/Operator
11–92
Standpipe Systems
• If system is equipped with pressure-reducing
valves, elevation pressure must be based on
total height of standpipe or zone being used.
• Vandals may open hose valves in dry
standpipes and leave them open. Teams may
have to go up or down the stairwell and close
the open valves.
Pumping Apparatus
Driver/Operator
11–93
Overcoming
Standpipe Impairments
• FDC has a frozen swivel — A double male
can be used with a double female
• FDC is unusable because of vandalism —
The standpipe riser can be charged at the
first-floor level by attaching a double female
to a hose valve at the first-floor level
(Continued)
Pumping Apparatus
Driver/Operator
11–94
Overcoming
Standpipe Impairments
• An individual hose valve on an upper floor is
found inoperative — A valve on the next floor
down can be used
• Single-riser building where standpipe is totally
unserviceable
– Hoist a line up the outside of the building
– Use a standpipe in an adjacent building
– Lay supply hose up the interior stairwell
Pumping Apparatus
Driver/Operator
11–95
Summary
• Driver/Operators must:
– Know how to operate fire pumps under a
variety of conditions
– Be able to engage the pump, to make it
operational, and troubleshoot any
problems that may develop.
(Continued)
Pumping Apparatus
Driver/Operator
11–96
Summary
• Driver/Operators must:
– Choose the best available water source –
onboard water tank, pressurized source, or
static source – and provide this water to
the pump
– Operate the pump to safely and effectively
supply water to attack lines and support
automatic sprinkler systems and
standpipes in buildings so equipped
Pumping Apparatus
Driver/Operator
11–97
Discussion Questions
1. What are the two basic pressurized water
supply sources used to supply a fire pump?
2. What are some of the dangers of operating
at a vacuum from a pressurized water
source?
3. Describe both a forward lay and a reverse
lay.
(Continued)
Pumping Apparatus
Driver/Operator
11–98
Discussion Questions
4. What checks should be made after making
hydrant connections but before opening the
hydrant?
5. Name methods for preventing the pump
from overheating.
6. Discuss the three methods for determining
how much more water a hydrant can
supply.
(Continued)
Pumping Apparatus
Driver/Operator
11–99
Discussion Questions
7. Name the steps for shutting down a hydrant
operation.
8. Name some indications that the pump is
cavitating.
9. What three things dictate the selection of a
drafting site?
10. Name some common causes of an inability
to prime the pump.
Pumping Apparatus
Driver/Operator
11–100