05 - IFSTA Chapter 05 Flashcards
How much does a cubic foot of fresh water weigh?
62.4lbs
When converted to steam, water expands by approximately how many times?
1,700
A 1 inch column of water, 1 foot high exerts what pressure?
0.434
What is the first principle of pressure?
Fluid pressure is perpendicular to any surface on which it acts
What is the second principle of pressure?
Fluid pressure at a point in fluid at rest is the same intensity in all directions
What is the third principal of pressure?
Pressure applied to a confined fluid is transmitted equally in all directions
What is the fourth principal of pressure?
The pressure of a liquid in an open vessel is proportional to its depth
What is the fifth principal of pressure?
The pressure of a liquid in an open vesssel is proportional to the density of the liquid
What is the sixth principal of pressure
The pressure of a liquid at the bottom of a vessel is independent of the shape of the vessel
What is atmospheric pressure at sea level?
14.7
How many feet will 1 psi raise a one square inch column of water?
2.304
Above sea level, atmospheric pressure decreases by aproximately how much psi for every 1,000ft?
0.5 psi
The friction loss in older hose can be as much as what percent?
50%
What is the first principle of friction loss?
If all other conditions are the same, friction loss varies directly with the length of the hose or pipe
(Double the length, double the FL)
What is the second principle of friction loss?
When hoses are the same size, friction loss varies approximately with the square of the increase in the velocity of the flow
What is the third principal of friction loss
For the same discharge, friction loss varies inversely as the fifth power of the diameter of the hose
What is the fourth prinicpal of friction loss
For a given velocity, friction loss is approximately the same, regardless of the pressure of the water
What pressure is required to reduce the volume of water by 1 percent?
30,000 psi
What are the most common type of valves used on most public water distribution systems?
Non-indicating
Which of the following cannot affect friction loss in fire hose
Weather
Water is considered to be:
incompressible
Water can be used to smother fires in what kind of combustible liquids?
Those with a specific gravity higher than 1
What principle of water makes it somewhat difficult to soak into dense material?
Its high surface tension
The term force is a simple measure of weight that is expressed in what unit of measurement:
pounds and newtons
Atmospheric pressure that surrounds the earth is:
greatest at low altitudes and lowest at high altitudes
Atmospheric pressure is commonly measured using what substance
mercury
how many times denser is mercury compared to water?
13.55
what is the most common example of gravity fed primary water source?
reservoir
what does a post indicator valve display when the valve stem inside the post is in the “closed” position?
shut
what is the most common type of valve used on a public distribution system?
nonindicating valve
all of the following are basic rates of consumption considered by engineers when desinging a water systems except for:
hourly consumption
which of the following are large pipes with relitevly widespread spacing,that convey large quantities of water to various points in the system?
primary feeders
which of the following best describes the term “elevation” in the fire service?
centerline of the pump to the bottom of the static water source
What is the atmospheric pressure at sea level?
14.7 psi
control valves found in a public water system are typically:
gate valves
which best describes the third princiople of water pressure?
confined fluid is transmitted equally in all directions
What does one cubic foot of water weigh?
62.4lbs
Water is a compound of hydrogen and oxygen formed when:
two hydrogen atoms combine with one oxygen atom
where do most private water supply systems receive their water from?
municipal water supply systems
air pressure that is less than atmospheric pressure is reffered to as:
a vacuum
One cubic foot of fresh water weighs how much?
62.4 lbs.
How can the amount of surface area exposed to water can be increased?
Using a fog pattern
When water converts to steam, it expands how many times its original volume?
1700 times
In which way can pressure NOT be measured?
kNa
The speed at which fluid travels through a pipe or hose is known as:
Velocity
Which way does fluid pressure act on a surface?
Perpendicular
How is the the pressure of a liquid in an open container relative to its depth?
Proportional
The pressure that surrounds the earth and exerts pressure on everything is known as:
Atmospheric pressure
The height of a water supply above the discharge orifice is known as:
Head pressure
Stored potential energy available to force water through pipes, fittings, hose an adapters is known as:
Static pressure
The pressure found in a water distribution system during normal consumption demands is known as:
Normal operating pressure
When the original flow of a stream is tripled, the friction loss is:
Increased nine times
How much pressure does it take to reduce the volume of water one percent?
30,000 PSI
Friction loss in a water system increases as the length of hose or piping what?
Increases
What can help recover pressure as friction loss increases?
A nozzle
Which one of the following will NOT affect friction loss?
Appliances
Which is NOT a method of moving water in a system?
Grid system
A grid system is defined as:
Water supply system that utilizes lateral feeders for improved distribution
What is not one of the three basic rates of consumption considered in the design for a water distribution system?
Minimum daily consumption
Private water supply systems are most commonly found in all of these places except:
Residential communities
One cubic foot of water weighs?
62.4 lb/ft3
At 212 degrees, what is the ratio of water to steam coversion?
1:1,700
What temperature can cause problems such as frozen pumps and hoselines during cold weather operations?
32 degrees
Which term is used to describe the simple measure of weight?
Force
Which principle of pressure is described as the pressure of a liquid in an open vessel is proportional to its depth?
4th principle
Which principle of pressure is described as fluid pressure at a point in fluid at rest is the same intensity in all directions?
2nd principle
Which principle of pressure is described as the pressure of a liquid at the bottom of a vessel is independent of the shape of the vessel?
6th principle
What is the atmospheric pressure at sea level?
14.7 PSI
What is the term used to describe any pressure less than atmospheric pressure?
Vacuum
What is the term used to describe the portion of the total available pressure not used to overcome friction loss or gravity while forcing water through pipes, fittings, hoses or adapters?
Residual pressure
Which principle of friction loss explains that friction loss varies directly with the length of the hose or pipe?
1st principle
Which principle of friction loss explains that when the flow remains constant, the friction loss in a hose will derease when the diameter of the hose is increased?
3rd principle
What is the term used to describe a sudden stoppage of water, moving through a hose or pipe, resulting in an energy surge being transmitted in the opposite direction?
Water hammer
Which method for moving water in a system using one or more pumps that takes water from the primary source and discharges it through the filtration and treatment processes?
Direct pumping system
What are the network of intermediate-sized pipes that reinforce the grid within the various loops of the primary feeder system?
Secondary feeders
What are the 3 components make up a grid system in water distribution?
Primary feeder, secondary feeder and distributors
What is the most common type of valve used on most public water distribution systems?
Nonindicating valve
Per IFSTA, how much does 1 gallon of water weigh?
8.3 lb/gal
What is the term used to describe the height of a water supply above the discharge orifice?
Head pressure
What is the pressure losses or gains due to gravity called?
Elevation pressure
At what temperature is water converted to a gas?
Above 212 F
If water is used to smother a fire, what must the specific gravity of the material on fire be?
Greater than 1.0
How many times does water expand to when converted to steam?
1700 times or more
Pressure is defined as what?
Force per unit area
What is the second principle of pressure?
Fluid pressure at a point in fluid at rest is the same intensity in all directions
What is the fifth principle of pressure?
The pressure of a liquid in an open vessel is proportional to the density of the liquid.
What is considered standard atmospheric pressure?
14.7 psi
How much head pressure is created if the water supply is 100 feet above you?
43.4 psi
What is considered the portion of the total available pressure not used to overcome friction loss or gravity while forcing water through pipes, fittings, hoses or adapters?
Residual pressure
What is the third principle of friction loss?
Friction loss varies inversely as the fifth power of the diameter of the hose
What determines the velocity for a given volume of water?
Diameter of the hose
What is a force created by the rapid deceleration of water causing a violent increase in pressure?
Water hammer
What system uses a water source at a higher elevation that the distribution system?
Gravity
Which part of a grid system contains large pipes (mains) with relatively widespread spacing?
Primary feeders
Which part of a grid system contains a grid arrangement of smaller mains serving individual fire hydrants and blocks of consumers?
Distributors
What type of valve is used to control underground water mains found on the supply main of installed fire protection systems where the operating stem of the valve extends above ground through a post?
Post Indicator Valve
Underground water pipes generally made of cast iron, ductile iron, asbestos cement, steel, plastic or?
Concrete
What is considered the average amount of water used per day based on the total amount of water used in a water distribution system?
Average daily consumption
Where are private water supply systems commonly found?
Large commercial, industrial or institutional properties
Who has control over a private water supply system?
The property owner
How much is ordinary fresh water considered to weigh for fire protection purposes?
8.3 lb./gal
When does water exist in a liquid state exist?
between 32 degrees and 212 degrees
When water is converted to steam at 212 degrees, it occupies approximately?
1,700 times its original volume
Force per unit area is a description of?
pressure
Which of the following is a simple measure of weight?
force
Water has a high surface tension that makes it?
somewhat difficult to soak into dense materials
Atmospheric pressure is?
greatest at low altitudes and least at very high altitudes
Atmospheric pressure at sea level is?
14.7 psi
Any pressure less than atmospheric pressure is referred to as a?
vacuum
Which of the following BEST refers to absolute zero pressure?
perfect vacuum
Which of the following BEST refers to the height of water supply above the discharge orifice?
head pressure
Stored potential energy available to force water through pipes, fittings hose and adapters is?
static pressure
The friction caused by water flowing through the pipes, valves and fittings is the difference between static pressure and?
normal operating pressure
The friction caused by water flowing through the pipes, valves and fittings is the difference between static pressure and?
normal operating pressure
The forward velocity pressure while water is flowing from a discharge opening is referred to as?
flow pressure
Which of the following occurs when a nozzle is above the level of the pump?
pressure loss
Which of the following occurs when a nozzle is below the level of the fire pump?
pressure gain
Which of the following refers to that part of the total pressure lost while forcing water through pipe, fittings, fire hose and adapters?
friction loss
Which of the is MOST likely to cause friction loss in fire hose?
improper gasket size
Which of the following determines velocity for a given volume of water?
diameter of hose
How much does fresh water weigh per cubic foot?
62.4 lbs
What is the specific gravity of water?
1
What hazard is presented at temperatures below 32 F when using water as the extinguishing agent?
Frozen pumps/ hoselines
Force is defined as what?
A simple measure of weight
What is the first principle of pressure?
Fluid pressure is perpendicular to any surface on which it acts
What is the third principle of pressure?
Pressure applied to a confined fluid is transmitted equally in all directions
As the atmospheric pressure increases, what occurs to the column of mercury when measuring pressure?
It becomes taller
What is the definition of static pressure?
Stored potential energy available to force water through pipes
What is elevation defined as?
Height of a point above sea level
What causes friction loss by definition?
The turbulence of water moving against the interior walls of hose or pipe
What is the second principle of friction loss?
Friction loss varies approximately with the square of the increase in the velocity of the flow if the hoses are the same size
What is the fourth principle of friction loss?
Friction loss is approximately the same regardless of the pressure on the water for a given velocity
What is the term used for water traveling at a speed too great that the friction will agitate the system?
Critical velocity
In what type of system uses more than one system to supply the water system?
Combination
What is defined as part of an overall water supply system that receives water from the pumping station and delivers it throughout the area?
Distribution system
What is the function of a valve in a water distribution system?
To provide a means for controlling the flow of water through the distribution piping
What type of control valve has a center screw in which it’s position determines if it is in the open or closed position?
Outside stem and yoke valve
What is caused by valves that are only partially opened?
High friction loss
What is defined as the average amount of water used per day?
Average Daily Consumption
What is an advantage of a private water supply system?
Either system (fire protection or domestic/industrial) is unaffected by service interruptions to the other system
What is atmoshperic pressure at sea level?
14.7 psi
What valve has the word open and shut appear in a window?
post indicator valve
What has hig surface tension and makes it difficult to soak into dense materials?
water
What a simple measure of weight?
force
What is force per unit area called?
pressure
What pressure refers to the height of water supply above the discharge orifice?
head
Wht is the force created by rapid deceleration of water called?
water hammer
What a water system has source at a higher elevation than the distribution system?
gravity system
What water system takes water from source and discharges through filtration and treatment by using 1 or more pumps?
direct pumping system
What valve control sprinkler system where the center screw indicates open or closed?
os&y vavle
what a hydrant getting water from one direction called?
dead-end hydrant
What kind of feed is a hydrant called getting water from 2 or more directions?
circulating feed
what occurs when a nozzle is above the level of the pump?
pressure loss
what is it called when velocity of stream goes past its pratical limit and friction becomes so great the whole system is aigitated?
critical velocity
Wht is an pressure less than atmospheric pressure called?
vacuum
what does water expand at converting to steam?
1700x its volume
What is the pressure found in a distribution system during normal consumption demands called?
normal operationg pressure
How much does water weight lb/gal?
8.3
what happens when nozzle is below the level of the pump?
pressure gain
Water can smoother combustible liquids when there specfic gravity is?
higher than 1
What is the boiling point of water
212 F
ordinary fresh water is considered to weigh
8.3 lb/gal
Water can be used to smother fires in combustible liquids whose specific gravity is higher than
1
At 212?F (100?C), water converted to steam occupies approximately how many times its original volume?
1,700
force per unit area
pressure
a simple measure of weight
force
The speed at which a fluid travels through a hose or pipe is determined by the pressure upon that fluid as well as the size of the orifice through which it is flowing.
velocity
Fluid pressure is perpendicular to any surface on which it acts
First Principle of Pressure
Fluid pressure at a point in fluid at rest is the same intensity in all directions
Second Principle of Pressure
Pressure applied to a confined fluid is transmitted equally in all directions
Third Principle of Pressure
The pressure of a liquid in an open vessel is proportional to its depth
Fourth Principle of Pressure
The pressure of a liquid in an open vessel is proportional to the density of the liquid
Fifth Principle of Pressure
The pressure of a liquid at the bottom of a vessel is independent of the shape of the vessel
Sixth Principle of Pressure
Atmospheric pressure at sea level is
14.7 psi
Atmospheric pressure at sea level is considered
standard atmospheric pressure
absolute zero pressure is called a
perfect vacuum
height of a water supply above the discharge orifice
head
stored potential energy available to force water through pipes, fittings, hose, and adapters
static pressure
the pressure in a system before it flows from a hydrant is considered
static
The pressure found in a water distribution system during normal consumption demands is considered the
normal operating pressure
Water is a compound made up of what elements?
Two hydrogen atoms and one oxygen atom
How is water’s density, or its weight per unit of volume, measured?
Pounds per cubic foot
What is the weight of fresh water?
62.4 lb/ft3 or 8.3 lb/gal
What is the specific gravity of water?
1
Which of these is not an advantage of water as an extinguishing agent?
Water is a goog conductor of electricity
What is the expansion rate of water that is converted to steam?
1,700 times
What is the term for force per unit area exerted by a liquid or gas measured in pounds per square inch or kilopascals?
Pressure
What is the term for a simple measure of weight, usually expressed in pounds or kilograms?
Force
What is the term for the speed at which a fluid is traveling?
Velocity
Which of these is not a principle of pressure?
Fluid pressure is parallelto any surface on which it acts
What is the atmospheric pressure at sea level?
14.7 psi
What is the term for any pressure less than atmospheric pressure?
Vacuum
What refers to the height of a water supply above the discharge orifice in the fire service?
Head pressure
What is the portion of the total available pressure not used to overcome friction loss or gravity while forcing water through pipes, fittings, hoses, or adapters?
Residual pressure
What is the term for pressure loss or pressure gain due to gravity?
Elevation pressure
What is the term for the loss of pressure created by the turblence of water moving against the interior walls of the hose or pipe?
Friction loss
Which of these is not a factor in friction loss?
Straight piping or hose
Which of these is not a way to reduce friction loss?
Increase the length of the lay and decrease the diameter of the hose
How can you prevent water hammer when water is flowing?
Slowly close nozzles and valves
What is the term for a part of the overall water supply system that receives the water from the pumping station and deliveres it throughout the area to be served?
Distribution system
What is the weight of water?
62.4 lb/ft^3
At 212 degrees Farenheit, water converted to steam occupies approximately how many times its original volume?
1,700 times
Any pressure less than atmospheric pressure is called what?
Vacuum
This term refers to the height of a water supply above the discharge orifice.
Head Pressure
As soon as water begins to flow, this pressure no longer exists.
Static Pressure
What is residual pressure?
The pressure remaining in the water supply system while water is flowing
Improper gasket size, the change in orifice by adapters, and valves cause what?
Friction Loss
In the first principle of friction loss, friction loss caries directly with what?
The length of the hose
Using the second principle of frcition loss to estimate, if a 3” line flowing 200 gpm has a friction loss of 3 psi, what would the friction loss of the line be if it was increased to 400 gpm?
12 psi
According the the third principle of friction loss, when the flow remains constant, the friction loss in a hose will what when the diameter of the hose is increasede?
Decrease
Mathematically, friction loss varies inversely to the what power as the diameter of the hose?
The fifth power
Flow pressure will always be greatest where and lowest where?
Greatest near the source of supply and lowest at the farthest point in the system
Which of the following will not affect friction loss?
Nozzle Type
To reduce friction loss caise by hose length or diameter, a firefighter can reduce the length of the lay or what?
Increase the diameter of hose
What is the force created by the rapid deceleration of water that causes a violent increase in pressure?
Water Hammer
What is a direct pumping system?
Uses one or more pumps that takes water from the primary source and discharges it to a series of pumps that force the water into the distribution system
What is a combination municipal water system?
Elevated sotrage tanks supply the gravity flow and whne the system pressure is low, the storage containers provide extra water by feeding it back into the distribution system
These types of pipes are relatively widespread and convey large quantities of water to various points of the system.
Primary feeders
These are a network of inermediate sized pipes that reinforce the grid with various loops and aid the concentration of the required fire flow at any point
Secondary Feeders
What kind of control valve for a sprinkler system has a center screw that indicates whether the valve is open or not?
Outside stem and yoke valve
Which valve has a yoke on the outside and a stem that opens the gate?
OS&Y
Which of the following best describes the forward velocity pressure of water flowing from a discharge opening?
flow pressure
Where do most private water supply systems get their water?
municipal water supply systems
Which of the following valves are commonly found on private water supply systems and contain a window in which the words “open” or “shut” appear?
Post indicator valve
How much does 1 gallon of fresh water weight?
8.33 lbs.
Which of the following are considered to be the two most common types of indicating valves?
PIV and OS&Y
Control valves in public water distribution systems are generally:
gate valves
Pressure found in a water distribution system during normal consumption demands is referred to as:
normal operating pressure
What is the most common type of valve found on a public water distribution system?
nonindicating valve
Engineers calculate the average amount of water used per day based on the total amount of water used in a water distribution system over a period of one year to determine:
the average daily consumption
Engineers observe the maximum total amount of water that was used in any 34 hour cycle over a period of 3 years to determine:
the maximum daily consumption
Engineers evaluate the maximum amount of water used in a 1 hour time span to determine:
the peak hourly consumption
Any pressure less than atmospheric pressure is referred to as:
a vacuum
Water is considered to have :
high surface tension
Why are wetting agents introduced into water based firefighting systems?
to reduce the surface tension and increase the penetrating ability
Atmospheric pressure decreases:
0.5 psi every 1000 feet
which of the following best describes an absolute zero pressure reading?
perfect vacuum
A liquid with a specific gravity greater than 1 is:
heavier than water
Which of the following occurs when water is converted to steam during fire extinguishment?
smothering
Gasoline has a specific gravity of .76 which makes it:
lighter than water
How is water’s density measured?
pounds per cubic foot
What is the specific gravity of water?
1
What is the speed of water called?
velocity
How much does 1 cubic foot of water weight?
62.4 lbs.
Which principle of pressure is defined as, “fluid pressure is perpendicular to any surface on which is acts.”
First Principle
Which principle of pressure is defined as, “the pressure of a liquid in an open vessel is proportional to its depth.”
Fourth Principle
What is defined as, “?potential energey available to force water through pipes, fittings, hose and adapters.”?
static pressure
The friction loss in older hose differs from new hose could be how high?
50%
What term refers to the center line of the pump or the bottom of a static water supply source above or below ground level?
elevation
How many principles of friction loss are there?
4
Which principle of friction loss is defined as, “if all other conditions are the same, frction loss varies directly with the length of hose or pipe?”
First Principle
When applying friction loss principles, what does the diameter of the hose determine?
velocity for a given volume of water
Suddenly stopping water results in an energy surge being transmitted in the opposite direction. This is known as what?
water hammer
What part of the water supply system receives the water from the pumping station and delivers it throughout the area servce?
distribution system
What is used to control the flow of water throughout a distribution system?
water main valves
What is the average amoutn of water used per day based on the total amount of water used in a water distribution syster over the period of one year?
average daily consumption
Where does private water supply systems commonly receive their water from?
municipal system
What are the most common type of valves used on most public water distribution systems?
nonindicating valves
What is a network of intermediate-sized pipes that reinforce the grid within the various loops of the primary feeder system called?
secondary feeders
A distribution system that provides circulating feed from several mains consitutes what?
grid system
What is the weight of one cubic foot of fresh water?
62.4 lb./ft.?
What is the weight of a gallon of fresh water?
8.3 lb./gal.
What is the specific gravity of water?
1
What is the expansion ratio of water coverted to steam?
1:1,700
The first principle of pressure states that fluid pressure is ___ to any surface on which it acts.
perpendicular
The pressure of a liquid in an open vessel is proportional to:
its depth.
What is the atmospheric pressure at sea level?
14.7 PSI
The readings of most pressure gauges are PSI ___ the existing atmospheric pressure.
in addition to
Any pressure less than atmospheric pressure is called:
vacuum
The height of a water supply above the discharge orifice is known as:
head pressure
Above sea level, atmospheric pressure decreases approximately 0.5 PSI for every __ above sea level.
1,000 feet
If all other conditions are the same, friction loss varies directly with the ___ of hose.
length
How much pressure is required to reduce the volume of water by one percent?
30,000 PSI
If a 1” tip is replaced with a ?” tip, the velocity of the water __, and the amount of flow __.
increases; decreases
Which of these would not affect friction loss?
Type of hose couplings
Each of these is a method of moving water in a system EXCEPT:
Natural draft system
The most common type of valve used on most public water distribution systems is:
nonindicating valve
The maximum amount of water used in any one-hour interval over the course of a day is:
Peak hourly consumption
The average amount of water used per day based on the total amount of water used is a distribution over the period of one year is:
Average daily consumption
A large concern of utilizing private water systems is:
Cross contamination of potable and nonpotable water
