Chapter 7 - Theoretical Pressure Calculations

Question 1

When making a friction loss calculation, the driver/operator must also account for ____________ as well as ______ that may be in use with the hoseline.

Answer 1

The length of the hose

Appliances

Question 2

Friction Loss Equation

Answer 2

FL = CQ²L

C = Friction loss coefficient
Q = Flow rate in hundreds of gpm. (gpm/100)
L = Hose length is hundreds of feet. (feet/100)

Question 3

Master stream appliance friction loss.

Answer 3

25 psi

Question 4

Appliance friction loss other than master stream devices.

Answer 4

10 psi

Question 5

Elevation pressure loss equation.

Answer 5

EP = 0.5H

EP = Elevation pressure
H = Height in feet

Question 6

Elevation pressure loss equation for a multi-story building.

Answer 6

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

Question 7

When considering pressure loss in an elevated waterway, assume a loss of __ psi for the waterway and master stream appliance.

Answer 7

25 psi

Question 8

Pump Discharge Pressure Equation

Answer 8

PDP = NP + TPL

TPL = Total pressure loss in psi (friction, elevation, and appliances)

Question 9

Net Pump Discharge Pressure Equation

Answer 9

NPDP = PDP - Intake Reading

PDP = Pump Discharge Pressure

Question 10

Friction Loss Coefficients

Answer 10

1 - 150
1.5 - 24
1.75 with 1.5 couplings - 15.5
2.5 - 2
3 with 2.5 couplings - 0.8
5 - 0.08

Question 11

Friction Loss Coefficients - Siamese Lines = length

Answer 11

2 - 2.5 - 0.5
3 - 2.5 - 0.22
2 - 3.5 with 2.5 couplings - 0.2

Question 12

Friction Loss Coefficients - Standpipes

Answer 12

4” - 0.374
5” - 0.126
6” - 0.052