Ch 7 Theoretical Pressure

Question 1

Friction loss

Answer 1

FL = CQ2L 
C is the coefficient of the hose being used 
Q2 is the flow in gpm squared 
L is the length of the hose.  
Find your square number first then work the problem 
Divide your gpm by 100 
Divide hose length by 100 
P. 212

Question 2

Friction loss is appliances flow less that 350 gpm is not calculated
Friction loss is appliances flowing 350 gpm or more is calculated
Friction loss is what psi________.

Answer 2

10 psi for appliances and 25 psi for master stream appliances.

P. 213

Question 3

Elevation pressure loss. Not building.

Answer 3

EP=.5xH
.5 is the constant
H is the height in feet

P. 214

Question 4

Elevation pressure loss in buildings

Answer 4

EP=5psi x number of stories - one story
5 psi for every story
Don’t count the first story no loss is psi yet.

P. 214

Question 5

Wyed hoselines. Equal length

Answer 5

Find the gpm in each wyed lines 
Find the friction loss of both lines 
Find the gpm of the supply line 
Find friction loss of supply line 
Add the friction loss of the supply lines and one of the attack lines. Also add any appliances if flow is greater than 350 gpm 

P. 215