Driver Operator Chapter 6 Flashcards
Gauge reading
Psig
Pressure exerted by the atmosphere at sea level
Atmospheric Pressure (14.7 psi)
Gauge reading
psig
The psi above perfect vacuum, absolute zero
psia
Any pressure less than atmospheric pressure
Vacuum
Absolute zero pressure
Perfect vacuum
Gauge readings of less than 0 psi
Negative Pressure
The height of a water supply above the discharge orifice
Head
The result of dividing the number of feet that the water supply is above the discharge orifice
Head Pressure
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 the discharge opening while water is flowing
Flow Pressure
The center line of the pump or the bottom of the static water supply above or below ground level
Elevation
The position of an object above or below sea level
Altitiude
What happens when a nozzle is above the pump
Pressure loss
What happens when the nozzle is below the pump
Pressure gain
Another term for both pressure loss and pressure gain
Elevation pressure
That part of the total pressure lost while forcing water through pipe, fittings, fire hose, and adapter
Friction Loss
Water is a compound of hydrogen and oxygen formed when:
A: One hydrogen atom combines with one oxygen atom.
B: Two hydrogen atoms combine with one oxygen atom.
C: Two oxygen atoms combine with one hydrogen atom.
D:Two hydrogen atoms combine with two oxygen atoms.
B: Two hydrogen atoms combine with one oxygen atom.
Water exists in a liquid state between: A: 0°F and 100°F B: 16°F and 110°F C: 20°F and 200°F D: 32°F and 212°F
D: 32°F and 212°F
For fire protection purposes, ordinary fresh water is generally considered to weigh: A: 5.25 lb/gal B: 7.26 lb/gal C: 8.33 lb/gal D: 12.8 lb/gal
C: 8.33 lb/gal
Water has the ability to extinguish fire in all the following EXCEPT: A: Cooling B: Smothering C: Absorbing heat from the fire D: Excluding carbon dioxide
D: Excluding carbon dioxide
What is specific heat?
A: The measure of the heat absorbing capacity of a substance
B: The heat required to raise the temperature of 1 pound of water 1°F
C: The specific point at which a substance absorbs enough heat to combust
D: The quantity of heat absorbed by the substance when it changes from a liquid to a vapor
A: The measure of the heat absorbing capacity of a substance