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