ch6 what is water and where does it come from Flashcards
The primary way water extingiushes fire is by, blank or absorbing the heat from the fire
cooling
a measure of the heat-absorbing capacity of a substance
specific heat
the amount of heat required to raise the temperature of 1 pound of water 1 degree farenheit
btu, british thermal unit
The blank, has taken the place of the calorie in the SI heat measurement
joule
the quantity of heat absorbed by a substance when it changes from a liquid to a vapor
latent heat of vaporization
The temperature at which a liquid absorbs enough heat to change to vapor is know as its blank
boiling point
Each pound of water requires approximately blank btu of additional heat to completely convert into steam
970
1 gallon of water will absorb blank btu of heat if all the water is converted to steam
9,346
At 212 degrees water expands approximately blank times its original volume
1,700
the tendency of liquid to possess internal resistance to flow
viscosity
the density of liquids in relation to water is known as
specific gravity
force per unit area
pressure
a simple measure of weight and is usually expressed in pounds
force
The weight of 1 cubic foot of water is approximately blank pounds
62.5
the speed at which this fluid travels is often referred to as blank
velocity
a pressure of 1 psi makes the column of mercury about blank inches tall
2.04
Any pressure less than atmospheric pressure is called
vacuum
blank in the fire servie refers to the height of a water supply above the discharge orifice
head
stored potential energy available to force water through, pipe, fittings, fire hose, and adapters
static pressure
at rest or without motion
static
that pressure found in a water distribution system during normal consumption demands
normal operating pressure
that part of the total available pressure not used to overcome friction loss or gravity while forcing water through pipe, fittings, fire hose, and adapters
residual pressure
a remainder or that which is left
residual
that forward velocity pressure at a discharge opening while water is flowing
flow pressure
blank refers to the center line of the pump or the bottom of a static water supply source above or below ground level
elevation
the position of an object above or below sea level
altitude
that part of the total pressure lost while forcing water through, pipe, fittings, fire hose, and adapters
friction loss
the size of the hose determines the blank for a given volume of water
velocity
if the velocity is increased beyond these limits, the friction becomes so great that the entire stream is agitated by resistance
critical velocity
high-volume systems should be protected with blank
dump valves
a fire hydrant that receives water from only one direction is known as a blank
dead-end hydrant
A distribution system that provides circulating feed from several mains constitutes a blank
grid system
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
primary feeders
network of intermediate sized pipes that reinforce the grid withing the various loops of the primary feeder system and aid the concentration of the required fire flow at any point
secondary feeders
Grid arrangement of smaller mains serving individual fire hydrants and blocks of consumers
distributors
valves for water systems are broadly divided into blank and blank
indicating and nonindicating
The blank is a hollow metal post that is attached to the valve housing
post indicator valve
the average of the total amount of water used in a water distribution system over the period of one year
average daily consumption
the maximum total amount of water that was used during any 24 hour interval within a 3 year period
maximum daily consumption
the maximum amount of water used in any 1 hour interval over the course of a day
peak hourly consumption
