GPM Formula

29.7 x D² x √NP (Solid Stream Nozzles Only: D=orifice diameter on solid bore nozzles)

Friction Loss Formula

CQ²L

Coeficient of 1.75" hose.

15.5

Coeficient of 2.5" hose.

2

Coeficient of 3" hose with 2.5" couplings.

0.8

Coeficient of 5" hose.

0.08

Coefficient of 3" hose with 3" couplings.

0.677

Formula for Evevation Pressure Loss in feet.

EP = 0.5H

EP= Elevation Pressure

H = Height in feet

*Loose 0.5psi per foot.

Formula for Elevation Presure Loss in stories

EP = 5psi x (number of stories -1)

When two hoselines of equal lengths are siamesed to supply a fire stream, friction loss is appoximately _____ percent of that of a single hoseline at the same nozzle pressure.

A. 10%

B. 25%

C. 35%

D. 50%

B. 25% (197)

When three hoselines of equal length are siamesed, the friction loss is approximately ____ percent of that of a single line of equal nozzle pressure.

A. 10%

B. 25%

C. 35%

D. 50%

A. 10% (197)

Formula for calculating friction loss with a siamese.

CQ²L

*With different coeficients chart than single line.

Smooth bore nozzle reaction formula:

 1.57 x D² x NP

Fog Nozzle reaction formula:

.0505 x Q x √NP

Pump Capacity:

150 PSI = 100%

200 PSI = 70%

250 PSI = 50 %

Atmosperic Presure: Sea level vs 9000 ft.

Sea Level: 14.7

9000': 10.2

Minimum intake pressure:

20 PSI

Nozzle pressures: Fog, Smooth Handline and Smooth Master:

Fog: 100psi

Smooth HL: 50psi

Smooth Master: 80psi

Loss of atmospheric pressure per 1000' feet of elevation gain:

1/2psi.

PDP =:

NP+FL+/-EL+AP

Pump sprinkler systems at ____psi.

150psi

Sprinkler/Standpipe FDC insertion loss is ____ psi?

25psi

Standpipes: pressure loss/gain per floor is ___psi/floor?

5psi

Static drop: Percentage vs addtional output.

0-10% = Can add 3 times current GPM output.

10-15% = Can add 2 times current GPM output.

15-20% = Can add 1 times current GPM output.

Maximum distance a nozzle can be away from a foam eductor?

200 Feet. (Nozzle must be open all the way).

Weight of 1 gallon of water:

8.33lbs.

Weight of a cubic foot of water?

62.4lbs.

When water converts to steam, it's volume increases _____ times.

1700

Head pressure formula:

# of feet/2.304

Fireground, rule-of-thumb, formula for solid stream nozzle reaction:

NR=Q/3

Define "Total Pressure Loss (TPL)".

FL +/- EP + AP, or PDP-NP

Friction loss for each appliance flowing MORE THAN 350 GPM.

10 psi per appliance

Friction loss for a master stream regaurdless of GPM flowing.

25 psi

Water exerts a pressure of ____ psi per foot of elevation.

0.434 psi.

Square root of 50

7.07

Friction loss of 2.5" hose flowing 250 gpm with 100 psi at fog nozzle.

15 psi.

Friction loss of 1.75" hose flowing 150 gpm with 100 psi at fog nozzle.

35 psi.

Condensed Q method of estimating friction loss works on what size hoses?

3", 4" and 5"

Condensed Q formula for 3" hose?

Q² (Q/100 2)

Condensed Q formula for 4" hose?

Q²/5 (Q/100² /5)

Condensed Q formula for 5" hose?

Q²/15 (Q/100² /15)

The formula for calculating the gpm flow rate for a tender in shuttling operations is:

Tank size in gallons - 10 % divided by trip time in minutes (dump to dump).

2.5" GPM with Fog Nozzle

250gpm

1.75" GPM with Fog Nozzle

150gpm

2.5" Friction Loss per 100' with Fog Nozzle

15psi

1.75" Friction Loss per 100' with Fog Nozzle

35psi

√100

10

√80

8.94

√50

7.07

TPL

FL+/-EL+AP, or PDP-NP

1 3/8 as a whole number

1.375

1 5/8 as a whole number

1.625

"Rule of Thumb" 1.75" GPM

150 GPM

"Rule of Thumb" 2.5" GPM

250 GPM

"Rule of Thumb" 3" GPM

500 GPM

"Rule of Thumb" 5" GPM

1500 GPM