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89 Cards in this Set
- Front
- Back
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What is the most commonly used fire extinguishing agent? |
Water
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Below what temperature does what exist in a solid form?
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32 ℉
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Water is it’s heaviest close to it’s ________ ______, and lightest close to its _______ ______.
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Freezing point; boiling point
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Ordinary fresh water is generally considered to weigh?
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62.5 lb/ft3 or 8.33 lb/gal
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A measure of the heat-absorbing capacity of a substance.
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Specific Heat
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Between 32℉ an 212℉ water exists in what state?
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Liquid
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Above what temperature does water covert to Gas?
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212 ℉
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The primary way water extinguishes is by _______.
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Cooling
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Specific gravity determines whether water will do what on the surface on another liquid, or visa versa?
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Float
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The amount of heat required to raise the temperature of one pound of water 1℉.
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Specific heat
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The specific Heat of a substance is a ratio between what two things?
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The heat needed to raise the temperature of a specified quantity of a material and the heat needed to raise the temperature of an identical amount of water the same number of degrees.
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The temperature at which a liquid absorbs enough heat to change to vapor.
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Boiling Point
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At 212℉ water expands how many times its original volume?
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1,700 times
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Water absorbs ____ times as much heat as does an equal amount of carbon dioxide.
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five
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The specific gravity of water.
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1
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The quantity of heat absorbed by a substance when it changes from liquid to a vapor.
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Latent heat of Vaporization
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Vaporization does not completely occur when water reaches 212℉, each pound of water requires an additional ______ of heat to completely convert into steam.
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970 BTU
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The speed with which water absorbs heat increases in proportion to what?
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The water surface area exposed to the heat.
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The tendency of a liquid to possess internal resistance to flow.
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Viscosity
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The density of a liquid in relation to water.
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Specific gravity
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A force per unit of area.
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Pressure
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Weight of one cubic foot of water?
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62.5 pounds
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The speed at which this fluid travels through a hose.
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Velocity
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Fluid pressure at a point in a fluid at rest is the same intensity in all directions.
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Second Principle of Pressure
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The pressure of a liquid in an open vessel is proportional to its depth.
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Fifth Principle of Pressure
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A simple measure of of weight and is usually expressed in pounds or kilograms.
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Force
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1 inch3 by 1 ft tall exerts a pressure of what at it’s base?
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0.434 lbs
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Fluid pressure is perpendicular to any surface on which it acts.
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First Principle of Pressure
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Pressure applied to a confined fluid from without is transmitted equally in all directions.
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Third Principle of Pressure
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The pressure of a liquid in an open vessel is proportional to the density of the liquid.
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Forth Principle of Pressure
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Mercury is __.__ times denser than water.
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13.55
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At sea level the atmosphere exerts what pressure?
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14.7 PSI
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At sea level a column of mercury is how tall?
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29.9 inches tall
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PSIA
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Pounds per square inch absolute
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Absolute Zero pressure.
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Absolute Vacuum
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The pressure of a liquid on the bottom of a vessel is independent of the shape of the vessel.
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Sixth Principle of Pressure
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A pressure of 1psi makes a column of mercury about _.__ inches tall.
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2.04
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PSIG
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Pounds per square inch gauge
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Any pressure less than actual pressure.
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Vacuum
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The fire service refers to the height of a water supply above the discharge orifice as what?
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Head
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Stored potential energy available to force water through pipe, fittings, fire hose, and adapters.
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Static pressure
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That pressure found in a water distribution system during normal consumption demands.
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Normal operating pressure
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The forward velocity flow pressure can be measured by using what?
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Pitot tube and Gauge
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The center line of the pump or the bottom of a static water supply source above or below ground level.
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Elevation
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Atmospheric pressure _____ as height above sea level increases.
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Drops
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Means at rest or without motion.
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Static
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Part of the total available pressure not used to overcome friction loss or gravity while forcing water through pipe, fittings, fire hose and adapters.
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Residual Pressure
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Forward velocity pressure at a discharge opening while water is flowing.
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Flow Pressure
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The position of an object above or below sea level.
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Altitude
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Above sea level, atmospheric pressure decreases approximately _._psi for every ____ft.
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0.5psi ; 1000ft
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Both pressure loss and pressure gain are referred to as What?
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Elevation pressure
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The friction loss in old hose may be as much as ___ greater than in new hose.
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50%
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For the same discharge, friction loss varies inversely as the fifth power of the diameter of the hose.
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Third Principle of Friction Loss
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For a given flow velocity, friction loss is approximately the same, regardless of the pressure on the water.
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Fourth Principle of Friction Loss
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When the diameter of the hose doubles, the area of thee hose opening increases approximately ____ times.
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Four
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The total pressure lost while forcing water through pipe, fittings, fire hose, and adapters.
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Friction loss
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If all other conditions are the same, friction loss varies directly with the length of the hose or pipe.
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First Principle of Friction Loss
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When hoses are the same size, friction loss varies approximately with the square of the increases in the velocity of the flow.
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Second Principle of Friction Loss
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With water being virtually incompressible, it requires _____psi to reduce it’s volume by 1%.
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30,000 psi
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When the velocity or speed of a stream increases beyond it’s practical limits and the friction becomes so great it causes agitation or turbulence.
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Critical Velocity
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What three characteristics of hose layouts cause friction loss?
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- Hose length
-Hose diameter -sharp bends (kinks) in the hose |
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Suddenly stopping water moving through a hose or pipe results in and energy surge being transmitted in the opposite direction. This surge is referred to as what?
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Water Hammer
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Three methods of moving water in a system.
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-direct pumping system
-Gravity system -combination system |
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When a fire hydrant receives water from two r more directions is said to have a what?
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Circulating Feed
Or Looped Line |
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Large pipes, with relatively widespread spacing, that convey large quantities of water to various points of the system for local distribution to the smaller mains.
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Primary feeders
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Realistically, a hose larger than _inches in diameter cannot be used for handlines.
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3 inches
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What are the four fundamental components of a Water system?
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-Source of water supply.
-Means of moving water. -Water processing or treatment facility. -Water distribution system, including storage. |
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Afire hydrant that receives water from only one direction.
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Dead-end Hydrant
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A distribution system that provides circulating feed from several mains.
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Grid System
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Grid arrangement of smaller mains serving individual fire hydrants and blocks of consumers.
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Distributors
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In residential areas there should be cross connecting mains at intervals of not more than what?
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600 ft
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What size mains should be used on principle streets and long mains not cross-connected at frequent intervals.
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12 inch diameter
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Valves for water systems are broadly divided into what two types?
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Indicating
And Non-indicating |
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What are the most common valves used on most public water distribution systems?
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Non-indicating valves
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In residential areas, the recommended size for fire hydrant supply mains is at least what?
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6 inches in diameter
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In the business and industrial districts, the minimum recommended size is an __ inch main with cross-connecting mains every ___ft.
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8 inch; 600 ft
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Water mains as large as __inches diameter can be found in major cities.
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48 inches diameter
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What are two common indicator valves?
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Post Indicator Valve (PIV)
And Outside Screw and Yoke (OS&Y) |
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What type of valves will you normally find in a water distribution system, normally installed in valve boxes or manholes?
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Non-indicating valves
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The average of the total amount of water used in a water distribution system over the period of one year.
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Average Daily consumption (ADC)
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The maximum amount of water used in any 1-hour interval over the course of a day.
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Peak Hourly Consumption (PHC)
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The peak hourly rate normally varies from _-_ times the normal hourly rate.
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2-4 times
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If there is any question about the reliability of a private water supply system or of its ability to provide an adequate amount of water for large-scale fire fighting operation, the department should do what?
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Make arrangements to augment the private water supply.
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Almost universally, private water supply systems maintain separate piping for what?
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Fire protection
And Domestic/industrial processes |
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The maximum total amount of water that was used during any 24-hour interval within a 3-year period.
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Maximum daily consumption (MDC)
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The maximum daily consumption is normally about _-__ times the average daily consumption.
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1 - 1½ times
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Private water systems exist for one of what three reasons?
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-To provide water strictly for fire protection purposes.
-to provide water for sanitary and fire protection purposes. -To provide water for fire protection and manufacturing processes |
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Where are private water supply systems normally found?
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Large commercial, industrial, or institutional properties.
Ma be found in some residential developments. |
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Water pipe that is underground is generally made of what?
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Cast Iron
Ductile iron Asbestos cement Steel Plastic concrete |
