Vol X 1012.10A Flashcards

1
Q

Hydraulics is the branch of engineering which deals with what?

A

the properties of water or other fluids at rest and in motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 2 aspects that most students and practitioners of fireground hydraulics identify?

A

theoretical and practical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define Static Pressure

A

the stored potential energy that acts equally in all directions in a fluid at rest

in other words: the pressure available from a hydrant or supply line before water is discharged from the apparatus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define Residual Pressure

A

the part of the total available pressure that is not used to overcome friction or gravity while water moves through the pipe, fittings, fire hose, and adaptors

in other words: the remaining pressure from the hydrant after water begins flowing from the apparatus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define Flow Pressure

A

the forward velocity pressure at a discharge opening while water is flowing

aka nozzle pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define Key Pumper

A

pumper positioned on a hydrant that is relaying water pressure from the hydrant to pumpers positioned away from the water source

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define Forward Pumper

A

pumper (or pumpers) in an attack position near the fire and normally at a distance from the hydrant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define “Unsupported” Position

A

a “forward” pumper which has laid a supply line in an attack position

a supply line is unsupported as long as it remains unpumped by a “key” pumper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define “Supported” position

A

a “forward” pumper which is a “key” pumper relaying water pressure from the hydrant through a supply line to the “forward” pumper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens to the volume a pumper can deliver when it must produce a higher pressure level?

A

the volume goes down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens to the actual capacity of the pump when supplied by pressure from a good water source? i.e. hydrant pressure

A

actual capacity of the pump increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define Net Pump Pressure

A

a measure of the pressure energy that is actually produced by the pump

in other words: it is the difference between the pump discharge pressure and the incoming pressure

looking at the gauge….
pump discharge pressure minus intake pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the 2 ways to estimate hydrant availability?

A
  1. percent method

2. first digit method

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the Percent Method

A

look for the percent drop in pressure from static pressure to residual pressure

0 to 10% - 3 more like lines
11 to 15% - 2 more like lines
16 to 25% - 1 more like line
26% and up - some more water is available

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the First Digit Method

A

Take the static pressure and subtract the residual pressure to find the drop in psi

Look at the first digit of the static pressure. If first digit is….

Times 1 = 3 more like lines
Times 2 = 2 more like lines
Times 3 = 1 more like line
Times 4 or greater = some more water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the purpose of the hydraulic theories?

A

aimed to help the pump operator achieve and maintain proper engine pressure during pump operations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does PDP stand for?

A

Pump Discharge Pressure

18
Q

What formula is used to find PDP?

A

PDP= NP + FL + AP +/- EL

PDP= Pump Discharge Pressure
NP = Nozzle Pressure
AP = Appliance Value
EL = Elevation
19
Q

How many rpm for
Red line?
1 1/2”?
Fog Hog?

A

Red line - 30 gpm

1 1/2” - 250 gpm

Fog Hog - 1000 gpm

20
Q

What is the nozzle pressure for all fog nozzles?

A

100 psi

21
Q

What are the guidelines for max volumes through hand lines and the number of personnel required to operate those lines?

A

up to 125 gpm - 1 persons

125-250 gpm - 2 persons

250-350 gpm - 3 persons

22
Q

All lines flowing greater than 200 gpm are considered what?

When must these lines be shut off in regards to repositioning the line?

A

“Stationary” lines

must be shut of BEFORE repositioning

23
Q

What is the MAXIMUM gmp for any handling at any time?

A

350 gpm

24
Q
Common master stream diameters and flows:
1 1/4 inch = 400 GPM
1 3/8 inch = \_\_\_\_\_ GPM
1 1/2 inch = \_\_\_\_\_\_ GPM
1 5/8 inch = 700 GPM
1 3/4 inch = \_\_\_\_\_ GPM
1 7/8 inch = 900 GPM
2 inch = \_\_\_\_\_\_ GPM
Control/fog nozzle = \_\_\_\_\_\_\_\_GPM
A
1 3/8" = 500
1 1/2" = 600
1 3/4" = 800
2" = 1000
Fog = 1000
25
Q

What does the “rule of eights” help you find?

A

the gpm flow through solid stream tips on master stream appliances

26
Q

What does the “rule of 8’s” state?

A

that if the fraction of the tip being used is put in a common denominator of 8, and then 2 is added to the numerator, the result will be the first digit of the approximate flow of the nozzle

ex: 1 1/2 = 1 4/8
4 + 2 = 6
Flow is 600 gmp

27
Q

What is the nozzle pressure of a solid stream nozzle on a handline? A solid stream nozzle on a master stream?

A

handline: 50 psi

master stream: 80 psi

28
Q

Define Friction Loss

A

the pressure lost as water travels through hose, piping, couplings, and appliances

29
Q

What are the 3 major factors that influence friction loss?

A
  1. the size of the hose
  2. the volume of water
  3. the length of the hose
30
Q

What are the 2 factors that influence friction loss that are not accounted for and why?

A
  1. The condition of the hose : because you have no control over it
  2. Kinks in the hose: because you shouldn’t have any
31
Q

What equation is used to find the Friction Loss per 100’ of handline?

A

[(gpm x n) /10] - 10

n= 3 for 1 3/4”

ex: 200 gmp through 100’ of 1 3/4’
[(200 x 3)/10] - 10
(600/10) - 10
60 - 10 = 50 psi FL per 100’

32
Q

What equation is used to find the Friction Loss per 100’ of 4”?

A

Q x (Q - 1) /4

ex: 500 gpm through 100’ of 4”

Q = 5
[5 x (5 - 1)] /4
(5 x 4) /4
20 /4 = 5 psi FL per 100’

33
Q

When accounting for appliance value in PDP equation, what is an appliance?

A

piece of equipment other than pumps, hose, and nozzles used in producing fire streams

34
Q

What is the minimum intake pressure for any pump?

A

20 psi

35
Q

How many psi do you add or subtract for elevation?

A

.5 psi per foot

5 psi per floor

36
Q

Anytime 2 or more lines are pumped, what must be set?

A

Pressure Relief Valve

37
Q

Handlines are NOT to be pumped over what at any time on the fireground?

A

250 psi

38
Q

How should sprinklers be pumped? (4)

A
  1. use 2 1/2” hose
  2. Connect ALL inlets on building
  3. Pump 100 psi with nothing showing
  4. Increase to 150 psi if evidence of working or active fire
39
Q

When pumping foam, what psi must you pump at?

A

200 psi

40
Q

When pumping foam, what elevation can you NOT exceed?

A

30’

41
Q

What is the MAXIMUM length of foam lines?

A

200’ of 1 3/4”