Equations / Friction Loss Flashcards
Equation B
Elevation pressure
Elevation Pressure =.5H
.5 x height in feet
Equation A
Friction loss
Friction loss = CQ2L
coefficient x flow rate (flow/100)2 x length of hose in (length/100)
Pump discharge pressure
PDP = NP + TPL
Pump discharge pressure = nozzle pressure (psi) + total pressure loss (friction loss and elevation pressure loss in psi)
NPDP: net pump discharge pressure
NPDP =PDP - Intake reading.
TPL: total pressure loss
TPL= friction loss + elevation pressure loss
Equation F
3in hose
FL per 100ft =Q2
Equation G
4in
FL per 100 ft= q2/5
Equation H
5in
FL per 100ft = q2/15
Gallons in 1 3/4 50ft length
7.5 gallons
Gallons in 3in 50ft length
12.5
Gallons in 5in 100ft length
107 gallons.
Volume of a cylinder formula
V= pie x r2x H
Gallons in 100ft in.
4 gallons
Gallons in one cubic foot
7.48
Hand method 2.5
Start with 2 and 100 from add by 50s including finger spacing. Friction loss equal the finger number multiplied by first digit of gpm.
Hand method 1 3/4.
Start with 1 and 100 gpm. Counting fingers only. Thumb equals 12 all fingers equal 9. Gpm increases by 25 per finger. Tip of finger multiplied by number value equals friction loss
Co E 3/4
1,100
Co E 1”
150
Co E 1.5”
24
Co E 1 3/4”
10 / 15.5
Co E 2.5”
2
Co E 5”
.08
Nozzle reaction solid tip
(1.57xd2)(np)
Nozzle reaction fog
.0505 x Q (Sq/np)
Gpm hand line
(29.7)(d2 x sq/np)
Hydrant Gpm formula
(29.7)(c x (d2 x sq/fp)
Hydrant coefficient
.7 big curve
.8 curve
.9 smooth curve
Min flow for interior structure fire
95-100 gpm
