Chapter 9 Flashcards
Provides a reading of residual pressure when the pump is operating from a hydrant or is receiving water through a supply line from another pumper
Master intake gauge
For a multistage centrifugal fire pump, switching from volume to pressure
can result in immediate doubling of previous discharge pressure.
Statements about a centrifugal pump
A centrifugal pump is unable to pump air and is not self priming
According to NFPA® 1901, pumpers with a capacity greater than 500 gpm (2 000 L/min) should be able to flow
at least 500 gpm
Statements about positive displacement pumps
hey serve a vital role on modern apparatus because of their ability to pump air and foam
Indicates the status of the vehicle’s alternator?
Ammeter
What is the purpose of slow-acting valve controls
Minimize risk of damage caused by water hammer when large volumes of water are being moved
Category of primer includes both the rotary vane primer and the rotary gear primer?
Positive displacement primers
Which part of a centrifugal pump transmits energy in the form of velocity to the water
Impeller
Type of pump consists of two gears that rotate in a tightly meshed pattern inside a watertight case
Rotary gear pump
Any significant deviation from normal oil pressure reading is MOST likely to indicate
an equipment malfunction
The simple devices that make use of the vacuum already present in the intake manifold of any gasoline-driven engine
Vacuum primers
When referring to pump wear rings and packing, why must very close tolerances be maintained between pump casing and the hub of the impeller
Any increase in opening lessens the effectiveness of the pump
Which pump design offers advantages such as more even weight distribution on the chassis and more usable compartment space
Front-mount pump
The most common type of valve and permits the full flow of water through a line with a minimum friction loss
Ball-type valve
The ability to initiate a successful drafting operation depends on creating
a lower pressure within the pump and intake hose than exists in the atmosphere
When pressure drops below a specified setting, the electronic pressure governor will:
return the engine to idle speed
In a centrifugal pump, the speed of the impeller dictates the amount of pressure developed and the faster the disk is turned
the harder water is thrown, giving the water more velocity
Main factor that influences a centrifugal fire pump’s discharge pressure?
Pressure of water when it enters pump from a pressurized source
Most manufacturers recommend that the centrifugal fire pump be drained
between fire calls.
Which pump may be offered by some manufacturers in a rear-engine design driven off the engine’s flywheel
Power-take-off (PTO) drive
Is used to operate the priming device when the pump will draft from a static water supply?
Primer control
type of positive displacement pump operates using a piston that moves back and forth in a cylinder?
Piston pump
In a modern apparatus, rotary pumps would MOST likely be used as which of the following types of pumps
As low volume, high-pressure pumps
Uses a compressor to supply an airline to a jet pump creating a Venturi Effect that primes the pump using no moving parts or lubricants
Air primers
In a centrifugal pump, with all other factors remaining constant, doubling the speed of the impeller will result in:
4 x times more pressure
When pumping in the parallel (volume) position:
each of the impellers takes water from a source and delivers it to the discharge.
A reason pump and suction drains are used on pumper apparatus?
Remove all water from the system in climates where freezing may occur
why it is essential that piping from the tank on board the apparatus be large enough to allow for adequate streams for fire attack?
Initially, many fires are fought with water from the tank on board apparatus.
Why is the rotary vane pump more efficient at pumping air than the rotary gear pump
Self-adjusting feature
Based on NFPA® 1901, as a minimum, all fire apparatus with a rated pump capacity of 750 gpm (3 000 L/min) or greater must be equipped with at least:
two 2½-inch (65-mm) discharges
Which of the following BEST describes the function of a pressure governor?
Regulates engine speed to match pump discharge requirements
It is generally recommended that intake relief valves be set to open when intake pressure rises more than:
10 psi (70 kPa) above the necessary operating pressure.
Drain valves provide a way to drain the hose side of the valve after the discharge valve and nozzle are both closed on:
discharge fittings.
Gate valves are most commonly operated by:
a handwheel.
The operation of a centrifugal pump is based on the principle that a rapidly revolving disk tends to throw water introduced at its center:
toward the outer edges of the disk.
Pressure control devices that are a part of a fire apparatus pumping system must operate within:
3-10 sec after the discharge pressure rises.
How does the driver/operator know when pumping operations may begin for most apparatus equipped with midship pumps?
Indicator light in cab
Which type of pump is MOST vulnerable to damage from exposure or a vehicle collision
Front-mount pump
What is the function of a booster line cooling valve
Diverts a portion of discharge water into the tank
The function of a thermal relief valve in newer centrifugal pumps?
Opens to allow overheated water to circulate between the pump and main water tank or into the atmosphere
Which of the following statements about mechanical seals is MOST accurate
It is important to operate the pump regularly to lubricate the seals.
Provides a relative indication of battery condition
Voltmeter
Which type of auxiliary cooling device is inserted into one of the hoses used in the engine cooling system so the engine coolant must travel through it as it circulates through the system
Marine cooler
Which type of pump is constructed with moveable elements that automatically compensate for wear, maintaining a tighter fit with closer clearances as the pump is used
Rotary vane pump
Which type of auxiliary cooling device works when water supplied by the fire pump passes through a coil or tubing mounted inside the cooler?
Immersion type auxiliary cooler
Which type of seal offers superior resistance to warping, stretching, and corrosion?
Ceramic
Which is typically driven through a gear box and a clutch connected by a drive shaft to the front of the crankshaft?
Front-mount pump
In a multistage pump, setting the transfer valve to series (pressure) results in:
a much higher pressure than would be achieved in parallel operation
Before being placed into service, the piping system and the fire pump itself must be capable of withstanding a hydrostatic test of:
500 psi (3 500 kPa).
When using a static water source, prime the pump by
removing all or most of the air from the pump.
Which type of positive displacement pump is the simplest of all fire apparatus pumps, from the standpoint of design?
Rotary pump
Modern versions of quarter-turn handles lock by:
rotating the handle in a clockwise direction.
Registers pressure as it leaves the pump, but before it reaches gauges for each individual discharge line
Master discharge pressure gauge
Generally found on skid-mounted pumps or older fire apparatus and require a great deal of maintenance to remove carbon deposits?
Exhaust primers
Purpose of using an oil supply or other type of fluid with conventional primers?
Seals the gaps between gears and case
powered by gasoline or diesel engines independent of the vehicle-drive engine?
Auxiliary engine driven pump
NFPA® 1901 requires all components of piping system to be:
made of corrosion resistant material.
Which may be part of a skid-mount assembly or may be mounted on pickup trucks?
Auxiliary engine driven pump
A characteristic of valves that control most of the intake and discharge lines from the pump?
Must be constructed to be airtight
Which type of pump has power supplied through the use of a split shaft gear case (transfer case) located in the drive line between the transmission and rear axle?
Midship pump
Which of the following displays engine speed in revolutions per minute?
Tachometer
Single-stage centrifugal fire pumps use a single intake impeller and a simple casing to provide flow capacities up to:
2,250 gpm (9 000 L/min)
For which of the following pumps is pressure determined by changes in the vehicle’s speed?
PTO
When pumping in the series (pressure) position:
all water from the intake manifold is directed into the eye of the first impeller.
the main feature of relief valves?
Ability to relieve excessive pressure within the pump discharge
Which pump design has the disadvantage of the driver/operator being more directly exposed to oncoming traffic than in other pump-mounting positions?
Front-mount pump
In multistage centrifugal pumps, the impellers generally
Have the same capacity
Pressure control devices that are a part of a fire apparatus pumping system must restrict the pressure from exceeding:
30 PSI
