Chapter 6 Flashcards
Why are most fog nozzles designed to operate at or below 100 psi (700 kPa) nozzle pressure?
a. Above this pressure, handlines will produce erratic fire streams.
b. Above this pressure, handlines become unwieldy for firefighters attempting fire suppression operations.
c. Above this pressure, pump discharges will not keep up with needed supply.
d. Above this pressure, nozzles will likely separate from the hose couplings.
b. Above this pressure, handlines become unwieldy for firefighters attempting fire suppression operations.
Which nozzle may require insertion of an inline shut off valve at a location back from the nozzle to increase safety and ease of operation?
a. Broken nozzle
b. Cellar nozzle
c. Chimney nozzle
d. Piercing nozzle
b. Cellar nozzle
Which of the following is the customary formula for determining nozzle reaction for solid stream nozzles?
Select one:
a. NR = 1.57 × d&squared; × NP
b. NR = d&squared; × NP
c. NR = 0.057 × d&squared; × NP
d. NR = 29.7 x d&squared; sqr NP
a. NR = 1.57 × d&squared; × NP
Which nozzle is commonly used in aircraft fire fighting or to apply water to voids, attics, or other areas inaccessible to standard fire streams?
a. Cellar nozzle
b. Chimney nozzle
c. Piercing nozzle
d. Broken nozzle
c. Piercing nozzle
Which of the following is the customary formula for discharge rate?
Select one:
a. GPM = d&squared; × sqr NP × 1.7
b. GPM= d&squared; × sqr NP × 2.5
c. GPM = 14.7 × d&squared; × sqr NP
d. GPM = 29.7 × d&squared; × sqr NP
d. GPM = 29.7 × d&squared; × sqr NP
Which of the following is a simple guideline for the customary system of measurement that may be used to achieve approximate solid stream nozzle reaction on the fireground?
a. NR = Q/3
b. NR = 0/2
c. NR = Q x 2.7
d. NR = Q × 1.5
a. NR = Q/3
Which manner of producing fog streams occurs by deflecting water around an inside circular stem in the nozzle?
a. Periphery-deflected streams
b. Impinging stream nozzles
c. Pressure-deflected streams
d. Circular stream nozzles
a. Periphery-deflected streams
