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What is back flushing?
Cleaning a fire pump or piping by flowing water through it in the opposite direction of normal flow
What is intake orifice at the center of a centrifugal pump impeller?
Impeller eye
What is a flowmeter?
mechanical device installed in a discharge line that sense the amount of water flowing and provides a readout in units of gallons per minute
What is the venturi effect?
Physical law stating that when a fluid is forced under pressure through a restricted orifice, the increase in velocity and a decrease in pressure. Because the fluid is under greater atmospheric pressure, it is forced into an area of lower pressure.
What is a relay?
To shuttle water between a source and an emergency scene using mobile water supply apparatus
What is cavitation?
Condition in which vacuum pockets form due to localized regions of low pressure at the vanes in the impeller of a centrifugal pump, causing vibrations, loss of efficiency, and possibly damage to the impeller.
What is the spiral, divergent chamber of a centrifugal pump in which the velocity energy given to water by the impeller blades is converted into pressure?
the volute
What is Net Pump Discharge Pressure (NPDP)?
Actual amount of pressure being produced by the pump
What is a grid system?
Water supply system that utilizes lateral feeders for improved distribution
According to the IFSTA handbook, what loss can be assumed for all master stream appliances, regardless of flow that will be used?
a. 0 psi
b. 10 psi
c. 25 psi
d. 35 psi
C
What is theoretical lift?
Theoretical, scientific, height that a column of water may be lifted by atmospheric pressure in a true vacuum; at sea level. This height is 33.9 feet.
Height will decrease as elevation increases
Hinged valve that permits the flow of water in one direction only
Clapper valve
What is Pump Discharge Pressure (PDP)?
Actual pressure of the water as it leaves the pump and enters the hoseline
What is a PTO (power take off system)?
Mechanism that allows a vehicle engine to power equipment such as a pump, winch, or portable tool; typically attached to the transmission
A hoseline operating on a 12th floor structure fire is connected to the building's standpipe system. What is the total pressure loss due to elevation?
a. 45 psi
b. 55 psi
c. 65 psi
d. 75 psi
B
What is duel pumping?
Where a strong hydrant is used to supply two pumpers by connecting the pumpers intake to intake.
What is a forward lay?
Method of laying hose from the water supply to the fire scene
What is reaction distance?
Distance a vehicle travels while a driver transfers a foot from the accelerator to the brake pedal after perceiving the need for stopping
What is nonpotable water?
Water that has not been examined, properly treated, and not approved as being safe for consumption
The combination of friction loss, elevation pressure loss, and loss associated with appliances is referred to as:
a. total pressure loss
b. primary friction loss
c. cumulative friction loss
d. elevation friction loss
A
What is nozzle reaction?
What is the vaned, circulating member of the centrifugal pump that transmits motion to the water?
The impeller
What is a type of control valve for a sprinkler system in which the position of the center screw indicates whether the valve is open or closed.
Outside Screw and Yoke (OS&Y) Valve
What is a centrifugal pump?
Pump with one or more impellers that rotate and utilize centrifugal force to move the water. Most modern fire pumps are of this type
The metric formula for elevation pressure loss is:
a. 2 x height in meters
b. 5 x height in meters
c. 10 x height in meters
d. 15 x height in meters
C