Notes from Class Flashcards
Friction loss in 2 1/2” hose, field hydraulics
Flow (GPM) minus 100, drop the last digit, gives FL per 100 ft
Example: 210-100 = 110, drop last 0 = 11 psi per 100
Applicable for 150 to 350 GPM
Friction loss in 4” hose, field hydraulics
Flow x2 -4 = FL per 100 ft up to 800 GPM
300 GPM = 2 psi 400 GPM = 4 psi 500 GPM = 6 psi 600 GPM = 8 psi 700 GPM = 10 psi 800 GPM = 12 psi
How many gallons of water are in a cubic foot of water?
7.48 gallons
Nozzle range rule of thumb
1 psi of NP = 1 foot of range
How much water is in 100’ of 1 3/4” hose?
12.5 gallons
How much water is in 100’ of 2 1/2” hose?
26 gallons
How much water is in 100’ of 4” hose?
65 gallons
How much water is in 100’ of 5” hose
102 gallons
How much does 1 gallon of water weigh?
8.34 pounds
What makes a diesel engine fire?
Heat of compression, not from spark of a spark plug
What types of brakes are used on all engines?
Front are disc brakes. Rear are drum brakes. Parking brake is spring brake.
Minimum air pressure to move apparatus?
60 psi
Spring brakes are automatically applied at what pressure?
40 psi
Normal operating pressure of brakes
90-120 psi
What pressure does the compressor kick in?
100 psi
What is brake fade?
When the brake drums become too hot and expand away from the brake shoes.
What does shoreline power do?
Provides conditioning of all batteries, power to the block heater, and on board chargers such as TIC, e-tool batteries, flashlights
Rule for volume vs. pressure mode
If you are going to flow more than half of the rated capacity of the pump, pump in volume.
Rule for switching between volume and pressure
Must be less than 50 psi difference between intake and discharge, or switch at idle
Static Pressure
Pressure of fluid at rest. You connect to a hydrant and open the hydrant but no water is flowing. The intake gauge will read static pressure.
Residual Pressure
Pressure remaining after water is flowing. Connect to a hydrant, open a discharge, and the intake gauge will drop from its static reading, showing residual pressure.
Head pressure Equation
Head pressure in psi = Height in feet/2.304
2 settings on the Blitzfire Fog Nozzle
Low Pressure = 55 psi. Standard = 100 psi
Distance between fire hydrants
700’ in residential, 400’ in commercial, 300’ in industrial
The most common type of positive displacement pump used in priming pumps are
Rotary vane
