Old Test Questions Flashcards
When performing a capacity test, the first desired pump pressure should be _______
150 psi
A force imposed upon a fire apparatus by partially filled water tanks due to stopping and turning is called a _____
Liquid surge
The angle from the rear point of ground contact of the rear tire to any projection of the apparatus behind the rear axle is called ______
Angle of departure
The angle formed by level ground and a line from the point where the front tires touch the ground to the lowest projection at the front of the apparatus is called _____
Angle of approach
The angle formed by level ground and a line from the point where the rear tires touch the ground to the bottom of the frame at the wheelbase midpoint is called _____
Ramp breakover angle
An operator obtains a reading of 17” of Mercury on the intake gauge while drafting and flowing water which indicates a lift of _____.
Approximately 17 feet.
A mobile water supply apparatus is equipped with a minimum tank capacity of _____
1000 gallons
Minimum requirements for a fire department pumper
Minimum pump capacity of 750 gpm and minimum tank of 300 gallons
The main purpose of a relief valve is to ______
Relieve excessive pressure within the pump discharge
Where does the water go when the relief valve is activated?
Back to the pump intake
When atmospheric pressure decreases, pumping ability ______
Decreases
2 methods of relay pumping
Maximum distance, constant pressure
Tank to Pump Flow Test
Apparatus with water tanks less than 500 gallons must provide TTP flow rate of 250 gpm. Apparatus with greater than 500 gallons must provde TTP flow rate of 500 gpm.
Maximum Lift Formula
L = 1.13 x inches of Mercury
Minimum dump flow rate of a tender per NFPA 1901
1000 gpm for the first 90% of the tank
Formula for area of a circle
A = Pi x R squared
What is the primary function of an auxiliary cooling system?
Control the temp of coolant in the apparatus engine during pumping operations
A 1 square inch column contains water to a height of 100 feet. What is the pressure in psi at the base of the column?
43.4 psi (1 foot = .434 psi)
A relief valve by-passes water from the discharge side of the pump to the ______
Pump intake
Theoretically, the maximum lift for a pump at sea level is _____
33.9 feet
The 50% pump capacity test is conducted at a net PDP of ______ for _____ minutes.
250 psi for 10 minutes
Operating engines below the minimum coolant temperature may result in _____
Inefficient combustion
Which primer uses the venturi principle?
Exhaust primer
Minimum water main size for business and industrial districts
8”
In a water distribution grid, the pipe that supplies individual hydrants and blocks of consumers is called a _____
Distributor
Pump capacity for a 20’ lift (drafting) at sea level
60%
Is a dump valve the same thing as an intake relief valve?
Yes
Disc brakes have ______ pad to rotor contact.
15%
Drum brakes have _____ pad to rotor contact.
90%
List 5 conditions that can cause an inability to draft
Drain valves open, intake valves open, dump valve not plugged, suction hose leaking, primer not run long enough, RPM’s not high enough, loose pump packing, strainer not submerged, in “pressure” instead of “RPM” mode
The spinning impeller creates ______
Flow
The impeller spins on a ______
Shaft
The rotary vane is a type of ______
Positive displacement pump (primer)
Water enters the impeller through the ______
Eye
The dump valve discharges excess incoming pressure to the ______
Ground
The first air tank in the air brake system is called the ______
Wet tank
Drum brakes are actuated from the slack adjuster to the _____
S-cam
When rotors or drums heat up and effect brake performance, this is known as _____
Brake fade
The valve that actuates the relief valve is called the _____
4-way valve
Another name for tandem pumping
Short relay
Rule of Thumb for Theoretical Lift
For every inch of Hg, water can be lifted 1 foot
If you double the size of the orifice, you decrease velocity _____
4 times
If you reduce the size of the orifice by 3 times, you increase velocity by _____
9 times
Centrifugal pumps make terrific fire pumps in that they have 100% ______
Slippage
The most common type of positive displacement pump used in priming pumps are ____
Rotary vane
Centrifugal pumps take advantage of ______
Positive intake pressure
