Chapter 5 Principles Of Water Flashcards
_______ is considered to be virtually incompressible, and its weight varies at different temperatures.It’s a density, or its weight per unit of volume, is measured in pounds per cubic feet.
Water
For fire protection purposes, ordinary freshwater is considered to weigh ______
62.4lb/ft3(1000kg/m3) or 8.3 lb/ gal(1kg/L).
T or f: water may also be used to smother fires in combustible liquids whose specific gravity is higher than one( heavier than water).
True
What is gasoline specific gravity?
0.72-0.76 which is less than one.
What is methylene chloride’s specific gravity?
1.33 higher than water
At 212°F water converted to steam occupies approximately______ its original volume, helping to dissipate heat in a well vented room. The expansion ratio is even greater in higher temperatures.
1700 times
Force per Unit area exerted by liquid or gas measured in pounds per square inch or kilopascals.This is also defined as force per unit area.
Pressure
Simple measure of weight usually expressed in pounds or kilograms. This measurement is directly related to the force of gravity, the amount of attraction the earth has for all bodies.
Force
Fluid pressure is______ to any surface on which should ask
Perpendicular
This principle of pressure is exerted by the weight of the water is perpendicular to the walls of the container. If this pressure is exerted in any other direction, the water will begin to move downward along the sides and rise at the center.
First Principle
This principle of pressure is fluid pressure at a point in fluid at rest is the same intensity in all directions. This principle is using hydrostatic testing.
Second principle
This principle of pressure states pressure applied to a confined fluid is transmitted equally in all directions. This principle is illustrated by a hollow sphere to which a pump is attached. 
Third Principle
And example of this principle of pressure would be a fire department pumper connected to a close standpipe.The difference between the pressure of the top of the standpipe to the pressure of the bottom of the standpipe.
Third Principle
This principle of pressure states the pressure of a liquid in an open vessel is proportionate to its depth.
Fourth Principle.
This principle of pressure states the pressure of a liquid in an open vessel is proportional to the density of the liquid.
Fifth Principle
T or F: 1 inch of mercury create the same pressure at the bottom of the container as 13.55 inches of water
True
This principle of pressure states the pressure of a liquid at the bottom of a vessel is independent of the shape of the vessel. This principle is illustrated by observing water and several different shaped containers, each having the same cross-sectional area at the bottom in the same height. The pressure is the same in each container.
Sixth Principle
T or F: Atmospheric pressure is greater and low altitude at least at very high altitude.
True
Atmospheric pressure at sea level is _____psi which is considered standard atmospheric pressure
14.7 psi ( 100kPa)
In the fire and emergency services a pressure that is somewhat less than atmospheric pressure is called a _______
Vacuum
This is needed to facilitate drafting of water from a static source.
Vacuum
This is an alternate term for pressure, especially pressure due to elevation. For every 1 foot increase in elevation, 0.434 psi is gained.
Head ( or head pressure)
This type of pressure is stored potential energy available to force water through pipes fitting hoses in adapters.
Static pressure
T or F: True static pressure is seldom found a municipal water systems because there is always some flow in the pipes do to normal use.
True
Pressure at the test hydrant While water is flowing, represents the pressure remaining in the water supply system while the test water is flowing and is that part of the total pressure that is not used to overcome friction or gravity while forcing water through fire hose,pipe fittings, in adapters
Residual pressure
While water is flowing from a discharge opening, the foward velocity pressure is considered____
Flow pressure
When measuring the forward Velocity of low pressure using a nozzle, A ________ nozzlemust be used with the Pitot tube and gauge
Smooth bore
Height Of a point above sea level or some other reference point. This refers to the centerline of the pump or the bottom line of a static water supply source above or below ground level.
Elevation
Geographic position of a location or object in relation to sea level. The location may be either above below or at C level. It is also the position of an object in relation to sea level.
Altitude
Gain or loss of pressure in a hose line due to a change in elevation.
Elevation pressure
T or F: Altitude impacts the production of fire streams because atmospheric pressure drops as height above sea level increases. This drop is a little consequence between sea level and approximately 2000 feet.
True
Above sea level, atmospheric pressure decreases approximately 0.5 psi for every 1000 feet.
True
Loss of pressure created by the turbulence of water moving against the interior walls of hose or pipe.
Friction loss
The fire service definition of this is that part of the total pressure lost by forcing water through pipe fitting fire hose in adapters
Friction loss
What are six common causes of friction loss and fire hose.
Movement of water molecules against each other.
Linings of hose/ laminating Hose
Couplings
Sharp bends/kinks
Change in his size or orifice by adapters
Improper gasket size
In this principle of friction, loss friction loss varies directly with the link of the hose or pipe.
First principle
This principle of friction loss states when hoses are the same size, friction loss very approximately with the square of the increase in the velocity of low.
Second principle
An example of this friction loss principle states a length of 3 inch hose flowing 200 GPM has a friction loss of 3.2 psi. As the flow doubles from 200 to 400 gpm, The friction loss increases four times to 12.8 psi. 2(squared)= 4 times
3.2x4= 12.8
Second principle
This principle of friction loss states for the same discharge, friction loss varies inversely as the fifth power of the diameter of the house. When the flow remains constant, the friction loss in a hose will decrease when the diameter of the hose is increased.
Third Principle
This principle of friction loss states for a given velocity, friction loss is approximately the same, regardless of the pressure on the water
Fourth principle
With water being virtually Incompressible, the pressure of ______psi is required to reduce its volume by 1%.
30,000
If the velocity is increased beyond Practical limits the friction loss will become so great that the entire system is agitated by resistance.
Critical velocity
Force created by the rapid deceleration of water, causes a violent increase in pressure that can be powerful enough to rupture piping or damage fixtures generally results from closing a valve or nozzle to quickly.
Water hammer
What are the three methods of moving water in a system.
Direct pumping system
Gravity system
Combination system
This method of moving water uses one or more pumps that take water from the primary source and discharges it through the filtration and treatment processes. From there, a series of pumps force of water into the distribution system.
Direct pumping system
This method of moving water uses a primary water source located at a higher elevation than the distribution center. The gravity flow from the higher elevation provides to water pressure. This pressure is usually only sufficient when the primary water source is located at least several hundred feet higher than the highest point in the water distribution system.
Gravity system
This method of moving water and most communities use a combination of the direct pumping in gravity system. In most cases, elevated storage tanks supply to gravity flow. These tanks serve as emergency storage and provide adequate pressure to the use of gravity. 
Combination system
Part of an overall water supply system not receive the water from the pumping station and delivers it throughout the area to be served
Distribution systems
Water supply systems that utilize lateral feeders for improved Distribution.
Grid system
What are the three components of a grid system.
Primary feeders
Secondary feeders
Distributors
In a grid system this consist of large pipes with relatively widespread spacing, that convey large quantities of water to various points in the system for a local distribution two smaller means.
Primary feeders
In a grid system this network of intermediate sized pipes that reinforce the grid within the various loops of the primary feeder system and aid the concentration of required fire flow at any point.
Secondary feeders
This type of grid system is a grid arrangement of smaller made serving individual fire hydrants and blocks of consumers.
Distributors
Type of valve used to control underground water mains found on the supply main of installed fire protection systems. The operating stem of the valve extends above ground through a post, and a visual means is provided at the top of the post for indicating.
Post indicator valves
A type of control valve for a sprinkler system in which the position of the center screw indicates whether the valve is open or closed.
Outside screw in yolk valve
These are the most common type valves used on most public water distribution systems.In a water distribution system, these are normally installed in valve boxes or manholes.
Non-indicating valves
Water has a higher surface tension that makes it somewhat difficult to soak into _____materials.
Dense
______ is an influence that causes change in speed, direction, or shape of a substance.
Force
And figure 5.6 a vessel having flat sides and containing water illustrates the :____ ___
First principle of pressure
And figure 5.7 pressure applied to a can find fluid is transmitter equally in all directions.
Third Principle of pressure
And figure 5.8 the pressure of a liquid in an open vessel is proportionate to its depth. 
Fourth principle of pressure
And figure 5.91 inch of mercury creates the same pressure at the bottom of the container as 13.55 inches of water.
Fifth principle of pressure
What is the common method of measuring atmospheric pressure?
Comparing the weight of the atmosphere with the weight of mercury.
For the purpose of this text PSI means PSIG( pounds per square inch gauge). A gauge reading 10 psi at sea level means that it is actually 10 psi G plus the atmospheric pressure of ___psi
14.7
Any pressure less than atmospheric pressure is called vacuum, an absolute zero pressure is called a:
Perfect vacuum
In the fire service, ____ refers to the height of a water supply above the discharge orifice. For example the water supply is 100 feet above the hydrant discharge opening. This is referred to as a 100 feet of _____?
Head
What are the principles of friction loss in piping systems?
Movement of water molecules against each other
Inside surface of piping
Pipe fittings
And valves
The inter-surface of a pipe is commonly referred as?
Coefficient of friction
And this principle of friction loss if all other conditions of the same friction loss very directly with the length of the hose or pipe
First principle of friction loss
This principle readily proves the advantage of larger size hose can be illustrated by one hose that is 2 1/2 inches in diameter and another that is 3 inches in diameter.
Third Principle of friction loss
True or false
The smaller the hose, the greater the velocity needed to deliver the same volume.
True
