Formulas Flashcards
Calculating Needed Fire Flow:
GPM = (Length x Width)
—————————————
3 x % of involvement
25,50,75,100% involvement
Page 100 ST
Placing the butt of a ladder for an ideal climbing angle:
Used L/4= distance the butt should be from the building.
Divide the used length of the ladder by four.
(The use length of a ladder is the vertical distance above the ground were the latter contact the building.)
Page 126 T
Calculating Thermal Radiation Intensity:
(T) to the 4th power
70° outside with a fire temperature of 1000°?
Fahrenheit can be converted to Rankine (R) using the formula-
R= (°F -32) + ( 491.67)
(Fire temp in R)to the 4th / (ambient temp in R) to the 4th
(1,460R)to the 4th / (530R) to the 4th = 57.6
Page 31 BC
Determining the Fire Load:
Weight of combustibles multiplied by the heat of combustion- expressed in pounds per square foot
Page 54 BC
Convert head in feet to head pressure:
Divide the number of feet by 2.304 = head pressure psi
Page 175 P&A
GPM or Discharge Rate:
GPM= 29.7 x D squared x square route of NP
Page 195 PA
Nozzle reaction for SOLID stream nozzles:
NR= 1.57 x D squared x NP
Page 203
Nozzle reaction for FOG stream nozzles:
NR= .0505 x Q x square route of NP
Page 204 PA
Friction loss:
FL= CQ squared L
Page 212 PA
Elevation pressure loss FEET:
EP= .5H
Page 214 PA
Elevation pressure loss MULTISTORY BUILDING:
EP= (5psi) x (Number of Stories-1)
Page 214 PA
Pup Discharged Pressure:
PDP= NP + TPL
Page 218
Net Pump Discharge Pressure (positive pressure source):
NPDP (positive pressure source) PDP - Intake Reading
Condensed Q:
3”
FL= Q squared
4”
FL= Q squared/ 5
5”
FL= Q squared/15
Page 288 PA
GPM Flowing Friction Loss calculation method:
Page 289 PA - study
Memorize 100-160 GPM 2.5” flow
100=3, 110-120=4, 130-140=5, 150=6,160=7
170-300 GPM - sub 10 from first 2 numbers (@300GPM 20 psi FL)
320- 400 GPM- add 3 psi per 20 extra GPM (@400 GPM you add and additional 15psi to the 300GPMs 20psi)
420-500 GPM- add 4 psi per 20 extra GPM (@500 GPM you add an additional 20psi to the 400GPMs 35psi)
Page 289. PA
Additional Water Available- Percentage Method:
Static-Residual x 100 / Static
If answer matches table 10.1 numbers add corresponding lines:
0-10 add 3x amount being delivered
11-15 add 2x amount being delivered
16-25 add 1x amount being delivered
25+ do not add
Pages 348/349
Additional Water Available- First Digit Method:
Static - Residual= A
Multiply the FIRST DIGIT of the static by 1,2, or 3
If the psi drop (A) is equal to or less than the static Multiplied by 3, than 1 additional equal flowing lines can be added.
Multiplied by 2, than 2
Multiplied by 1, than 3
Page 349 PA
Additional Water Available- Squaring the Lines:
Static - Residual= A
Number of desired TOTAL lines SQUARED = B
A x B = C (total psi loss)
Finally take STATIC Pressure - C = (20 psi or more?)
Page 350 PA
Assumed Flow Rates for Squaring the Lines Method(additional water available Table 10.2):
1 1/2 inch 125 GPM
1 3/4 175
2 200
2 1/2 250
Page 351 PA
Calculating Theoretical Lift:
Actual atmospheric pressure X waters pressure per square foot in intake hose
Page 404 PA
Determining Max Lift:
L= 1.13 Hg (inches of Mercury)
Page 405 PA
Pressure Correction:
PC= Lift + Total Intake Hose Friction Loss/ 2.3
750 gpm 4” 7 psi per 10’— 8.5 per additional 10’
5” 4.5 psi per 10’— 5.5 per additional 10’
1000 gpm 5” 4.5 psi per 10’— 6 per additional 10’
1250 gpm 5” 12.5 psi per 10’— 14.5 per additional 10’
Page 408 PA
Net Pump Discharge Pressure (Draft):
NPDP (Draft)= PDP + PC
Page 409
Square or Rectangle Pool Capacity:
C= 7.5 x L x W x D
Page 416
Round Pool Capacity:
C= 7.5 x pie r squared x D
Page 417
Relay Distance:
P= R/D + 1
R= relay distance D= distance from table 12:1
Page 430 PA
WATER SHUTTLE Flow Rate:
Flow= .9 x TS / Travel/Trip Time
Travel/ Trip Time = ROUND trip
Page 465 PA
Travel Time:
Travel = (1.7) Distance + .65
Time = minutes Distance = ROUND-trip
Page 466 PA
Handling Time:
Handing Time= Fill Site Time + Dump Site Time
Page 466 PA
TENDER Flow Rate:
Flow= .9 x TS / Travel + Handling Time
Page 465 PA
Back Pressure while Educting Foam:
BP= NP + FL( from eductor to nozzle) and Elevation Pressure
Page 495 PA
Foam Application Rate for specific nozzle:
AR= Flow Rate/ Fire Area sq/ft
Page 491 PA
Percent of Concentration in Foam Solution:
%= Conductivity of Solution - Conductivity of Water /500
Page 530 PA
Kinetic Energy or Wind/Falling object:
E= 1/2 MV squared
Page 71 BC
Fill/Dumps Site Times:
Fill Time = M-B + (capacity/flow)
(Dump Time is the same; Handling Time is the total of Fill+Dump Time)
