Chapter 5 Principals Of Water Flashcards
Freezing point of water
Boiling point of water
F. Below 32 degrees Fahrenheit(0 degrees Celsius)
B. Above 212 degrees Fahrenheit(100 Celsius)
For fire protection purposes, ordinary fresh water is considered to weigh how much pounds per cubic foot?
How much per gallon?
- 4 lb/ cubic foot
8. 3 lbs per gallon
Do Combustible liquids with specific gravity greater than one sink or float above water?
Where does gasoline fall?
If it’s greater than one it will sink below water.
Gasoline specific gravity is 0.72 so it sits on top water.
Once water is converted to steam, it occupies approximately how much more times it’s originally volume?
1700
Water can be reactive with?
Combustible metals
Sodium metal
Certain fuels
Triethyl aluminum
In this book , pressure is defined as?
It is easily confused with?
Force per unit area
Force
Atmospheric pressure is greatest at blank altitudes and least at blank altitudes
Low altitudes and higher altitudes
A pressure of 1 psi makes a clum of mercury about how tall?
How tall is a column of mercury at sea level?
- 04 inches
2. 04*14.7= 29.9 inches tall
Any pressure less than atmospheric pressure is called….
Vacuum
Describe head pressure
For every one foot increase in elevation, how much psi is gained?
Refers to the height of a water supply above the discharge
.434 psi
Stored potential energy available to force water through pipes, fittings, hose, and adapters.
Static pressure
The pressure found in a water distribution system during normal consumption demands
Normal operating pressure
The difference between static pressure and normal operating pressure is the…
Friction caused by water flowing through the pipes, valves, and fittings of the system
The portion of the total available pressure not used to overcome friction loss or gravity while forcing water through the pipes, fittings, hose, and adapters
Residual pressure
Above how many feet sea level must pumpers work increasingly harder to produce proper pressures?
At sea level atmospheric pressure decreases .5 psi for every how many feet?
Above 2,000 feet. Because there is
less Atmospheric pressure. Because the less dense atmospheric pressure reduces a pumpers effective lift when drafting
1000’
When hoses are the same, friction loss varies approximately with the square of…
The increase in the velocity of the flow
When the flow remains constant, the friction loss in a hose will decrease when the diameter in a hose…
Is increased
When comparing friction loss in different size hoses, you multiply the diameter of each hose to what power and then divided those results.
To the fifth power
3inch hose vs. 4 inch hose
3^5/4^5 equals 243/1000=.24
So a 4 inch hose only has a quarter of the friction loss of a 3 inch hose.
Or 76 percent reduction in friction loss by using the 4 inch hose.
Uses one or more pumps that takes water from the primary source and discharges it through the filtration and treatment processes.
Direct pumping system
Uses a primary water source located higher than the distribution system.
Gravity system
Most communities use this water system. It’s the gravity and direct pumping put together
Combination system
What are two things that may be added to water at a treatment center?
Fluoride or ozone
What are the main concerns for the fire department when it comes to water treatment facilities?
Natural disasters, loss of power, or a fire, etc. could hamper the pumps ability to send water
Inability of the treatment center to process water fast enough to meet demand
There is much less pressure loss in a water distribution system when water…
Fire hydrants are supplied from two or more directions
When a hydrant receives water from 2 or more directions
It has a circulating feed or a looped line
A distribution system that provides circulation by feed from several mains constitutes a ?
Grid
Name the three parts of a grid and which one feeds the hydrants?
Primary feeders
Secondary feeders
Distributors- serve individual hydrants and blocks of consumers
How Often should valves be operated to keep them in good condition? This is for valves distributed throughout the grid system.
Once a year
Name two common indicating type valves
Post indicator valve
Outside screw and yoke valve
For an outside stem and yoke valve the threaded portion of the stem is out of the yoke when the valve is open or closed?
Where is this type of valve most commonly used?
Closed
Sprinkler systems
These are The most common type of valves used on most public water distribution
Where are they most normally installed on a water distribution system?
Non-indicating valves
Valve boxes or manholes
Encrustations and sedimentation of pipes can be reduced by?
Flushing hydrants periodically
What is the Average daily consumption ADC?
It is the average amount of water used per day based on the total amount of water used in a water distribution system over the period of one year
What is the maximum daily consumption?
It is the maximum total amount of water that is used during any 24 hour interval within a three-year period. Unusual situations such as refilling a reservoir cleaning should not be considered in determining the max daily consumption.
What is the peak hourly consumption? PHC
It is the maximum amount of water used in any one hour interval over the course of a day
