Home > Preview
The flashcards below were created by user
lynch329
on FreezingBlue Flashcards.

1 gallon of water weighs?
8.35 lbs

1gallon of water in CI (cubic inches)
231 ci

Cubic inches (ci) in a cubic foot (cf)
1728

1 cf of water weighs?
62.5 lbs





Height to create 1 psi?
2.304 ft

1 psi will raise a column ?
2.304 ft

Pressure is based on ht. Preferred formula for psi if you have height?
psi = h x .434

Formula for height if you have psi?
H = psi / .434

Formula for volume in a cylinder in cubic ft.
V = .7854 x D^{2} x L x 7.481(gallons in cf)

Formula for cubic feet?
CF = .7854 x D^{2 }x L

Formula for tank volume (rectangle)?
L x W x H = CF

Formula for volume in gallons (rectangle)?
7.481 gallons in a CF
L x W x H x 7.481 = volume in gallons

Atmospheric pressure at sea level?
14.7 psi

Max elevation decrease for drafting?
33.9 ft

Head pressure is for elevation. Add ___ psi per foot.
add 4.34 psi per foot of elevation

Back pressure is for decrease in elevation. Decrease ___ psi per foot.
decrease 4.34 psi per foot

Pressure while water standing still in pipes.
Static pressure

Standard pressure in pipes.... fluctuates during peak water hrs.
normal operating pressure

Left over pressure
residual pressure

Pressure of the line while flowing
Flow pressure

Pressure of the pump while pumping
net pump pressure

Convert tip size into decimal equivelalent.
Divide top number by bottom number.
example  3/4" tip = .75

Formula for figuring discharge of a smooth bore nozzle.
Q = 29.7 x D^{2} x √NP

Formula for calculating hydrant discharge
 Q = 2.97 x D^{2} x √P x .9
 √P = (sq root of hydrant Pressure)

Nozzle reaction is measured in ___ not ____.
lbs not psi

Formula for calculating nozzle reaction on smooth bore nozzle.
1.57 x D^{2} x NP = NR

Formula for calculating nozzle reaction for fog nozzle.
.0505 x Q x √NP = NR

Define TPL
total pressure loss  to be added to nozzle pressure. Includes FL, elevation, appliance loss.
note* when asked for TPL only include the higher FL line in equation

Difference between TPL and TPDP?
(Total Pump Discharge Pressure)
TPDP is TPL + NP.

Define Equation A
 FL = CQ^{2}L
 (used to determine FL in fire hose)
 C is coefficient. # related to size hoze in diameter
 Q is quantity GPM. Divide by 100. ex GPM/100
 L is length. Divide by 100. ex L/100

Coefficient for 1 1/2"
24

Coefficient for 1 3/4
15.5


Coefficient for 3" with 2 1/2" coupling
.8

Coefficient for 3" with 3" coupling
.677



When laying multiple lines, add which nozzle pressure?
The higher pressure

Fog nozzle pressure
100 psi

Smooth bore nozzle pressure
50 psi

Master stream nozzle pressure
80 psi

Add ____ psi for pressure loss in an appliance if gpm greater than ____
add 10 psi if greater than 350 gpm

Appliance loss for a master stream?
25 psi regardless of flow

Is a standpipe considered an appliance?
Yes

Define equation B
 Used for elevation loss or gain
 E = H x .5

Maximum GPM a hose can handle
Critical velocity

Critical velocity of 1"
30 gpm

Critical velocity of 1 1/2"
100 gpm

Critical velocity of 1 3/4"
200 gpm

Critical velocity of 2 1/2"
300 gpm

Critical velocity of 3"
500 gpm

Critical velocity of 5"
1200 gpm

Define equation C
 EP = 5 psi x (number of stories 1)
 3rs story is + 10 psi

Do you add appliance loss?
Yes

Truck to truck pressure loss? How much do you add?
 20 psi
 If you use 2 lines, add 10 psi to each line.

Psi to operate a standpipe?
 150 up to 10th floor.
 180 psi above 10th floor.

Max psi for standpipe?
200 psi

Add 10 psi to standpipe for every ____ feet of hose.
100 ft

Formula for sprinkler system?
1/2 P (pressure) + 15 = Q (gpm)

To operate sprinkler system start at ____ psi.
 150 psi.
 Go up in increments of 25 psi.
 Max of 200 psi.

Define equation E
Net Pump Discharge Pressure
NPDP = PDP  intake readings.

