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
-Potential energy due to elevation
- Potential energy due to 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 of 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 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
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
