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Flashcards in Chpt 7 Deck (101)
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1

Fire service _______ is the study of the characteristics and movement of water as they pertain to calculations for fire streams and fire ground operations

Hydraulics

2

The scientific or more exact calculations are commonly referred to as

Theoretical hydraulics

3

Is the term for the less exact but certainly more user friendly and forgiving calculation methods used on the fire ground

Fireground hydraulics

4

To be as accurate as possible when performing hydraulic calculations, you should use the manufactures recommended ________specific to the actual used on your hose or appliance, with your fire apparatus under the guidelines of your fire department

Nozzle pressure

5

Flow tests with your equipment will confirm the most precise _____ to use

Pressures

6

Fighting fire with water is a matter of ______ versus heat generation, British thermal units, joules, or kilocalories

Flow rate

7

To extinguish a fire, sufficient flow must be applied to over come the heat generated by the fire a rate referred to as the _______

Critical rate of flow

8

The real goal of the driver operator is to deliver the correct ______ to the nozzle

Flow

9

The ______ is the total pressure needed to overcome all friction, appliance, and elevation loss while maintaining adequate nozzle pressure to deliver effective fire streams

PDP

10

PDP equation

PDP = NP + FL

11

Is the pressure required at the nozzle to deliver the fire stream and flow rate for which the nozzle was designed

Nozzle pressure

12

Smooth bore nozzles on a handline are normally flowed at a NP of _____.

50 psi

13

Some master stream smooth bore nozzles are rated less than

80 psi

14

Fog nozzles are generally rated at

100 psi

15

Three standard nozzle pressures, all of which are dictated by the type and the use of the nozzle, are generally sufficient for most fire ground operations

70 psi for all fog nozzles

50 psi for smooth bore handline nozzles

80 psi for smooth bore master stream nozzles

16

When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction to that of the first body.

Newton third law of motion

17

Is the opposing reaction that occurs as water is expelled from the nozzle or the force that pushes back on the firefighter when he or she flows water

Nozzle reaction

18

Calculating nozzle reaction should not be attempted at the fire scene but rather determined during

Training sessions

19

To calculate nozzle reaction in a smooth bore use the formula

NR = 1.5 x d2x np

20

To calculate nozzle reaction in a fog nozzle use the formula

NR= 0.0504 x gpm x NP

21

Is the volume of water moving through the nozzle during a specific time period; it is measured in units or gpms

Flow rate

22

Is the pressure lost from turbulence as water passes through pipes, hoses, fittings, adapters, and appliances

Friction loss

23

Friction loss formula

FL = C Q2 L

24

When flowing two identical lines that have the same nozzle pressure and flow and that are of equal size, length, and elevation, both lines require the same

Pressure

25

Under normal conditions you always fully open a valve to prevent excess turbulence and FL through the valve; however, partially closing a valve sometimes necessary to prevent excessive pressure from being delivered. For those discharged requiring a lesser pressure, you must open the valve just enough to deliver the desired pressure, a practiced referred to as

Gating the valve

26

Calculations must be adjusted for the distance the nozzle is above or below the pump, which is referred to as

Elevation pressure

27

The pressure lost when the nozzle is above the pump is known as

Elevation loss

28

The pressure gained when the nozzle is below the pump is known as

Elevation gain

29

EP could be _____ if the nozzle and the pump are at the same elevation

Zero

30

Water exerts a pressure of _____ psi per 1 foot of water column

0.434 psi