Hydraulics and Water Supply Flashcards
Water is most useful for FF when it exists in its
Liquid state
Water exists in its liquid state between what temps
32 and 212 degrees F
Water is _____ in its liquid state
Incompressible
1 cubic foot of water contains
7.48 gallons in a liquid state
Waters density is measured in
pounds per cubic foot
Water is most and least dense in which states
Dense - freezing point
Least dense - boiling point
How many pounds does a gallon water weigh
8.34 pounds
What are the primary ways in which water extinguishes fire
Cooling and smothering
What 2 laws of physics are important for firefighting
Law of specific heat
Law of latent heat of vaporization
All substances have a given capacity to absorb heat explains what
Law of specific heat
Amounts of heat transfer are measured in
BTU or Joules
This is the amount of heat required to raise the temp of 1 pound of water 1 degree F
BTU
The ratio between the amount of heat needed to raise temp of specified quantity and amount of heat needed to raise temp of identical by same number of degrees
Specific heat of any substance
Water absorbs heat _____ more effectively than what
500 times, Carbon dioxide
The amount of heat that water can absorb when it changes from a liquid to a vapor is referred to as
Latent heat of vaporization
The fire service has commonly used a ratio of ____ for water to steam conversion
1:1,700
Waters considerable amount of surface tension limits what
Its ability to soak or penetrate combustibles
The study of water at rest and the science behind that study is called
Hydrostatics
The pressure at a point in a liquid is applied equally in every direction is known as
Pascal’s law
Function of a given force applied over a specific area
Pressure
The pressure of a liquid in an open container is what
Proportional to its depth
Pressure created by a static liquid is equal to what
Weight x height
Pressure expressed in units of feet of water instead of pounds per square in
Head
The amount of pressure created by the height of the column of water
Head pressure
Stored energy that can perform once its released
Potential energy
What 2 sources of potential energy is a static body of water subject to
-Elevation
-External pressure sources
This is the ability to do work
Energy
Study of the characteristics and physical properties of water in motion
Hydrokinetics
What 2 types of energy are considered with hydraulics
Potential and kinetic energy
This states that the total energy within a system will remain constant
Principle of conservation of energy
Energy cannot be ___ or ___, it simply changes forms between what
Lost or destroyed,
Potential and kinetic energy
The principle of conservation of matter states
Matter can’t be created nor destroyed
This is defined as force per unit area
Pressure
1 cubic foot of water weighs
62.4 pounds
What is the standard atmospheric pressure
14.7 psi
Lower atmospheric pressures affects what operation for a driver
Drafting
Any pressure less than atmospheric pressure is called?
Vacuum
Absolute zero pressure is called
Perfect vacuum
The stored potential energy available to force water through pipe, fittings, fire hose, and adapters
Static pressure
Part of the total available pressure not used to overcome friction loss or gravity
Residual pressure
What is the single variable with the greatest impact on friction loss
Pipe diameter
What are the 4 basic components any water supply system should have
-Water supply source
-Water treatment facilities
-Mechanism for forcing water through system
-System of piping to transport water
What are the 3 basic rates of consumption for water supply systems
Average daily
Maximum daily
Peak hourly
What are the 2 basic categories of water supply sources? Which is more commonly used
Surface and ground water; Surface is more commonly used
Contaminants of water can be removed by what 4 processes
Sedimentation
Filtration
Coagulation
Chemical treatment
This uses gravity to cause particles to fall out of water
Sedimentation
What are the 3 basic types of water movement systems
Gravity (least common)
Direct pumping
Combination (most)
What are the 3 common designs for water system piping arrangements
Tree system
Circle/belt system
Grid system
Largest pipes in a grid system
Primary feeder
Comprise the network of intermediate sized pipes that reinforce the grid
Secondary feeders
Smaller mains serving individual fire hydrants and blocks of consumers
Distributors
What are dead end hydrants
Hydrants that receive water from one direction
What are the size ranges of primary, secondary, and distributors
Primary - 8 to 72 in
Secondary - 6 to 36 in
Distributors - 4 to 20 in
The AWWA currently recommends a minimum diameter of ____ for new pipe installation
8 inches
Valves for water distribution systems are broadly divided into what 2 types
Indicating and non indicating
What are 2 types of common indicating valves
PIV and OS&Y
These are commonly used on private water supply systems
PIV
These are most commonly found on sprinkler systems
OS&Y
What are the different hydrant color codes
Class AA - light blue
Class A - green
Class B - orange
Class C - red
What are the flows for each hydrant color
Light blue - 1,500 or greater
Green - 1,000-1,499
Orange - 500-999
Red - < 500
Flow tests should be done every
5 years
Electronic devices that automatically convert the velocity pressure to a flow quantity readout
Flowmeters
This test is the only reliable way for fire service personnel to determine the quantity of water available for fire protection
Water flow test
The calculated amount of water needed to extinguish a fire in a given occupancy
Required fire flow
When conducting an available water test the residual pressure should not drop below
20 psi
What is the minimum required residual pressure when computing the available water for area flow test results
20 psi
What are the 3 formulas commonly used by the fire service
Iowa state formula
National fire academy formula
Insurance services office formula
Who was the actual pioneer for fog stream firefighting technology
Captain Glenn Griswold
Flame production stops when the oxygen level falls below
15 percent
This formula is considered reliable only if 4 floors or fewer are on fire
National fire academy formula
This formula is applicable to all structures other than 1 and 2 family dwellings not exceeding 2 stories
ISO Formula
What are ISO formula coefficients for:
Wood frame
Ordinary
Heavy timber
Noncombustible
Fire resistive
1.5
1.0
0.9
0.8
0.6
ISO recommends the calculated fire flow be rounded to the nearest ___ if flow is < _____ and the nearest ____ if the flow is > _____
250 gpm for <2,500
500 gpm for >2,500
Fire flow should never drop below ____ regardless of calculation
500 gpm
The design of automatic sprinklers is regulated by
NFPA 13
What are the 2 recognized methods of designing automatic sprinklers
Pipe schedule and hydraulic calculation method
Which of the 2 methods of sprinkler design does not evaluate friction loss
Pipe schedule method
This sprinkler design method uses mathematical calculations to determine the required piping sizes and other design factors
Hydraulic calculation method
Fixed piping systems within tall or otherwise large buildings
Standpipe systems
The design and operation of standpipe systems is dictated by
NFPA 14
Which standpipe system is specifically designed for fire department use
Class 1
If a structure has a class 1 standpipe, it is required to have a minimum flow rate of ____ and each additional standpipe must have available ____, up to a max of
500 gpm
250 gpm
1,250 gpm
Which standpipe system is designed for use by building occupants
Class 2
Class 2 standpipe systems typically contain
75 ft. of unlined cotton hose
Class 2 standpipes require a flow of only ____ at a minimum ____
100 gpm
65 psi
The minimum design criteria for fire apparatus is specified in
NFPA 1901
What 2 types of fire apparatus are not covered under NFPA 1901? What are the covered under
Wildland fire fighting NFPA 1906
Airport crash trucks NFPA 414
What is the minimum pump capacity for a vehicle to be considered a fire department pumper
750 gpm
NFPA 1901 requires an on board tank capacity of at least _____ to be considered a fire department pumper
300 gallons
Scaled down versions of fire department pumpers
Initial attack fire apparatus
The smaller sizes of initial attack fire apparatus are commonly called
Minipumpers
Vehicles that can pump and roll use what to power the fire pump
Separate motor or power take off (PTO)
What are the pump and water tank capacities for type 1, 2, and 3 water tenders
300 gpm, 5,000 gallons
200 gpm, 2,500 gallons
200 gpm, 1,000 gallons
To be considered a fire department tanker, the apparatus must have a water tank of at least
1,000 gallons
What are the water tank limitations for single rear axle and tandem rear axle chassis
2,000 gallons
4,000 gallons
What factors should fire departments consider when choosing what type and size tanker
Terrain
Bridge weight limits
Budget
Compatibility with mutual aid tankers
A quint is a fire apparatus that is equipped with
Aerial device
Ground ladders
Fire pump
Water tank
Fire hose
To be considered a true quint that apparatus must have
At least 1,000 gpm pump
NFPA 1901 requires quints to have a water tank capacity of
At least 300 gallons
What are the 3 general class NFPA 414 divides ARFF trucks into
Major fire fighting vehicles
Rapid intervention vehicles
Combined agent vehicles
What type of pump is used in nearly all fire department pumpers
Centrifugal pump
What are centrifugal pumps unable to do
Cannot move air
These are used as priming pumps to evacuate air from the centrifugal pump
Positive displacement pumps
Every forward stroke causes water to discharge, every return stroke causes the pump to fill with water known as
Single acting piston pump
The addition of 2 or more valves enable the pump both to receive and discharge water on each stroke of the piston, known as
Double acting piston pump
The output capacity of a piston pump is determined by what
Volume of cylinder and speed of piston travel
Almost all modern pumping apparatus use what type of positive displacement pump as a priming pump
Rotary type positive displacement pump
These consist of 2 tightly meshed gears that rotate inside a water tight case
Rotary gear pump
The rotary gear pump is what type of pump and why
Positive displacement pump
Each pocket in the gears contains a fixed volume
This contains a rotor that is mounted off center inside the pump casing
Rotary vane pump
The centrifugal pump is considered what type of pump and why
Nonpositive displacement pump
Doesn’t pump a definite amount of water with each revolution
What are the 2 primary parts of a centrifugal pumps
Impeller and a casing
This transmits energy to the water in the form of velocity
Impeller
This collects the water and confines it to convert the velocity to pressure
Casing
Where is water introduced into the pump
The eye of the impeller
A water passage that gradually increases in cross-sectional area as it nears the pump’s discharge outlet
Volute
What 3 factors influence a centrifugal pump’s discharge pressure
-Amount of water discharged
-Impeller speed
-Pressure of water when it enters pump
What are the 2 basic types of centrifugal pumps the fire service uses
Single and multi/two stage
What position is commonly used when pumping multiple or large diameter supply lines and why
Volume position because both impellers take water from intake
What position is commonly used when supplying attack lines operating on tank water
Pressure position
When the changeover valve is in this position, it directs all water from the intake manifold into eye of first impeller
Pressure postion
The process of switching between pressure and volume is sometimes referred to as
Changeover
Switching from volume to pressure immediately does what
Doubles the discharge pressure
What are the most common pump drive arrangements on fire apparatus
Auxiliary engine
PTO
Front mount
Midship transfer
Rear mount
These pumps receive their power from a separate engine
Auxiliary engine driven pumps
Auxiliary engine driven pumps are typically powered by engines with
< 50 horsepower and pumping capacity of 400 gpm or less
These are powered by a driveshaft connected to a PTO on the chassis transmission
Power take off driven pumps
The amount of pressure developed depends on what
The speed of the engine turning the pump
If a truck is designed for pump and roll, the driver should operate the vehicle by what
The pressure gauge instead of speedometer
Which is the most common drive and mounting arrangement for modern pumping apparatus
Midship transfer driven pumps
What supplies power to the pump in a midship transfer driven pump
Transfer case
With the engine idle and the pump engaged, most speedometers will read
Between 10 and 15 mph
What is a disadvantage of midship pumpers
They can’t be used for pump and roll operations
Modern fire apparatus use what 2 types of pressure control devices
Relief valves and pressure governors
These are intended to reduce the possibility of water hammer damaging the pump
Pressure relief valves
It is recommended to set intake pressure relief valves to open when
Intake pressure rises more the 10 psi above desired pressure
This regulates the engines power output to match the the pump’s discharge requirements
Pressure governor
What are the 2 types of pressure governors
Mechanical and electronic
This governor uses a pressure sensing element connected to the pump discharge manifold
Electronic pressure governor
To draft water from a static source, a fire pump must be able to create what
Lower pressure within pump and intake hose than exists in atmosphere
Primers fall into what 3 categories
Vacuum
Exhaust
Positive displacement pumps
The oldest and simplest type of primer used in the fire service
Vacuum
All pumping apparatus must be equipped with what for the engine that drives the pump
Auxiliary cooling system
What are the 2 types of auxiliary cooling systems found on apparatus today
Marine type and immersion type
This is inserted into one of the engines cooling system hoses so that the circulating engine coolant travels through it
Marine type auxiliary cooling system
This is mounted with the radiator coolant passing through the body of the cooler so that the water from the fire pump passes through a coil mounted inside the cooler
Immersion type auxiliary cooling system
This allows a small amount of water to leak around the packing and prevent excessive heat buildup
Lantern ring
Water flow through the pump and apparatus is controlled by
Intake piping
Discharge piping
Pump drains
Valves
NFPA 1901 requires all piping system components to be _____. Most are constructed of what
Corrosion resistant
Cast iron, brass, stainless or galvanized steel
Before being placed into service the piping system must be able to withstand
Hydrostatic test of 500 psi
All intake pipes to a centrifugal pump are located where? What is the exception
Below eye of the impeller
Exception is the tank to pump line
NFPA 1901 requires piping to be at least
2 1/2 inches in diameter
This can be used to circulate water through the pump to prevent overheating when no lines are flowing
Tank fill line
What is the most common valve design on fire apparatus
Ball valve
This must be connected to the intake side of the pump
Master intake gauge
This indicates residual pressure when the pump is operating from a pressurized source
Master intake gauge
When pumping from a draft, the master intake gauge indicates the amount of what
Vacuum at the pump intake during priming or draft ops
This gauge registers the pressure as it leaves the pump but before it reaches individual discharge line
Master discharge pressure gauge
This record the engine speed in revolutions per minute
Tachometer
This shows the temperature of the coolant in the engine that powers the fire pump
Pumping engine coolant temp indicator
This shows whether an adequate supply of oil is reaching the critical areas of the engine that powers the fire pump
Oil pressure indicator
This provides a relative indication of battery condition and alternator output
Voltmeter
This device increases or decreases the speed of the engine that powers the fire pump
Engine throttle
This indicates the water flow in gallons per minute
Flowmeter
Service tests should be conducted
At least yearly
What are the 3 categories of preservice tests
Manufacturers
Pump certification
Acceptance
As a minimum the manufacturer of the apparatus is required to perform what 2 tests
Road and hydrostatic test
During pump testing the apparatus shall continuously pump its rated volume capacity at 150 psi for how long
2 hours
During pump testing the volume, discharge pressure, intake pressure, and engine speed should be recorded
Every 15 minutes for the duration of the test
This test is only performed on apparatus equipped with fire pumps whose rated capacity is
Pumping engine overload test,
750 gpm or greater
This test checks the pumps ability to evacuate water from the pump, piping, and intake hose so that it may draw water from a static water supply source
Priming device test
For pumps with a capacity of 1,250 gpm or less, the time required to achieve a prime should not exceed
30 seconds
For pumps with a capacity of 1,500 gpm or less, the time required to achieve a prime should not exceed
45 seconds
During the priming device test the pump must obtain a max vacuum of at least
22 inches of mercury
This test is performed to ensure there are no air leaks within the pump, piping, and intake hoses when preparing to draft from a static water supply source
Vacuum test
The requirements for service testing fire department pumping apparatus are contained in
NFPA 1911
What should be done to the hose before starting pump testing
Scribe a mark where the hose and couplings meet
What is the minimum size hose that can be used for pump testing
2 1/2 in
If the mark on the hose used for pump testing moves more than ____ from the coupling what should be done
3/8 inch, stop and replace the hose
This is the total work done by the pump to get water into, through, and out of the pump
Net pump discharge pressure
When pumping from a pressurized source, the net pump discharge pressure is ____ than the pressure shown on the gauge
Less
When at draft, the net pump discharge pressure is _____ than the pressure shown on the discharge gauge
More
What can be used instead of a pitot gauge to determine flow from the nozzles
Flowmeter
This test checks the overall condition of the engine and the pump
Pumping test
This test is to ensure that the piping between the water tank and the pump is sufficient to supply the minimum amount of water specified by NFPA and the manufacturer
Tank to pump flow test
If the fire pump test to less than 90% of its capabilities when new, what 2 options are available
Take pump out of service
Give pump lower rating based on results
The resistance to flow is commonly called
Friction loss
What factors influence the amount of friction loss in hose
Diameter of hose
Length of hose
Age and condition of hose
What are the 4 types of hose appliances
Wyes
Siamese
Water thiefs
Manifolds
These divide 1 hose line in to 2 separate hose lines of equal size
Wye
These combine 2 or more hose lines into a single line
Siamese
What are the maximum recommended pressures for handline and master stream nozzles
Handline 50 psi
Master 80 psi
Many authorities have followed the rule of thumb that the tip diameter of solid stream nozzles should
Not exceed one half the diameter of the hose
What angle is the solid streams maximum horizontal reach
32 degrees
What stream of water is discharged from a smooth bore nozzle? Fog-stream nozzle
Solid stream
Straight stream
This is the rate of motion of a particle in a specific direction
Velocity
This is the rate of travel regardless of direction
Speed
Fog stream selection must consider what 5 factors
Gravity
Water velocity
Fire stream pattern
Water droplet friction with air
Wind
Most fog nozzles are designed for optimum flow and stream operation at what discharge pressure
100 psi
What are the 3 basic types of fire streams
Solid, fog, and broken
What is the maximum amount of water that may be safely flowed through a hand line nozzle
350 gpm or less
Any flow above 350 gpm is considered for
Master streams
The most flexible nozzle available to the fire service is
Fog stream nozzle
Most modern fog stream nozzles operate on the principle of
Periphery deflection
Fog stream nozzles are designed to operate at a nozzle pressure of
100 psi
These nozzles produced different volumes depending on the particular variables of their design
Variable flow nozzles
These nozzles flow a specific amount of water at a specific nozzle discharge pressure on all stream patterns
Constant flow nozzles
These nozzles maintain a constant nozzle pressure of approximately 100 psi no matter how much pump discharge pressure
Automatic nozzles
What are the practical working limits for the velocity of fire streams
60 to 120 feet per second
What can make water “slipperier” and reduce the friction loss in the system
Class A foam or other wetting agents
When multiple hose lines supply different nozzles or apparatus, what must be done
Calculate friction loss for hose line and set pressure for hose that requires most pressure
2 or more hose lines laid to supply a single master stream device is called
Siamesed lines
What is the modern friction loss formula
FL = CQ(squared)L
What are the friction loss coefficients for 1 3/4, 2, 2 1/2, 3, and 5 inch hose
15.5
8
2
0.8
0.08
Water exerts a pressure of _____ per foot of elevation
0.433 psi
What is the formula to estimate the pressure loss or gain in a multistory building
EP = 5psi x number of stories minus 1
Appliance friction loss generally is considered significant only where total flow through the appliance is
At least 350 gpm
How much pressure loss is considered for each appliance used in a hose assembly
10 psi
We will assume a friction loss of ____ for all flows through what systems or devices
25 psi
Master stream appliances
Aerial apparatus waterways
Standpipe systems
What are the 3 basic types of hydraulic calculators available to the fire service
Manual
Mechanical
Electronic
The pressure losses combined with the required nozzle pressure are used to determine what
Pump discharge pressure
The intake pressure at a receiving pumper should never be
Below 20 psi
The operator must set the pump discharge pressure for the hose line with
Greatest pressure demand
The amount of pressure the pump is actually creating is called
Net pump discharge pressure
When at draft, the nest pump discharge pressure is _____ than the pressure shown on the discharge gauge
More
When at draft, the net discharge pump pressure is the sum of
Pump discharge pressure and intake pressure correction
NFPA 1901 requires standard fire department pumpers to carry at least
800 ft of 2 1/2” or larger supply hose
This is the pumper connected to the water supply at the beginning of the relay operation
Source or supply pumper
This is the pumper at the fire scene; receives water from the relay
Attack pumper
What is the most crucial safety device for relay pumping operations
Intake pressure relief valve
All pumpers are rated to pump their maximum volume at a net pump discharge pressure of
150 psi
What are the 2 basic designs for relay pumping operations
Max distance relay method
Constant pressure relay method
Which relay method involves predetermining the volume of water to be flowed by the relay and spacing the pumpers appropriately
Maximum distance relay mthod
Most standard fire department pumpers are rated to flow their ____ at 15o psi, ____ at 200 psi, and ____ at 250 psi
Max volume
70%
50%
This relay method establishes the maximum flow available from a particular relay setup
Constant pressure relay method
When a constant pressure relay is in operation, operators should keep correcting their pump discharge pressure to
175 psi
The relay’s maximum capacity will be determined by what
The capacity of its smallest pump and hose line
The relay pump operators should try to maintain the pump intake pressure between
20 and 30 psi
If the intake pressure rises above ____, the relay pump operator should
Open the dump line valve
If the attack pumper is equipped with an adjustable intake pressure relief valve it should be set between
50 and 75 psi
Relay operations should be shut down in order from
Fire scene to source pumper
What are the 4 basic types of sprinkler systems
Wet pipe
Dry pipe
Deluge
Preaction
NFPA 13 divides occupancies into what 3 classifications
Light hazard
Ordinary hazard
Extra hazard
These occupancies have a low rate of heat release if they catch fire
Light hazard
These occupancies include combustibles that do not exceed 8 feet in height
Ordinary hazard group 1
These occupancies include combustibles that do not exceed 12 feet in height
Ordinary hazard group 2
What are the 2 basic methods of system design used to ensure piping is properly designed and sized for sprinklers
Pipe schedule method and hydraulic calculation method
What type of sprinkler system is always filled with water and is the most common
Wet pipe system
In this sprinkler system, air under pressure replaces the water in the pipes above the sprinkler valve in the riser
Dry pipe system
This sprinkler system combines features of both deluge and dry pipe, and is used in places where preventing water damage is important
Preaction system
What are the basic components of all sprinkler systems
Sprinklers
Piping
Valves
Water supply
FDC
What are the main components of closed sprinklers
Heat sensing device
Deflector
Discharge orifice
What are the 3 types of sprinkler deflector shapes
Upright
Pendant
Sidewall
What is the most common size of orifice in automatic sprinklers
1/2 inch
These are used to shut off water supply to the system when replacing sprinklers or performing maintenance
Control valves
What are the 4 types of indicating valves commonly used as sprinkler control valves
OS&Y
PIV
WPIV
Indicating butterfly valve
What are the 5 types of standpipe systems recognized by NFPA 14
Dry automatic
Wet automatic
Semiautomatic
Dry manual
Wet manual
These standpipes contain air under pressure that holds the water beneath a dry pipe valve
Dry automatic
These are the most common standpipe systems
Wet automatic
What is the primary difference between dry automatic and semiautomatic standpipes
The remote control activation device that has to be operated
These standpipes do not have an attached permanent water supply
Dry manual
These standpipes are attached to a small water supply source only enough to keep the pipes filled with water
Wet manual
Piping for standpipes must be capable of withstanding pressures of up to
300 psi
