IFSTA 9 Fire Pump Theory Flashcards
Define positive displacement pump
Self priming pump that utilizes a piston or interlocking rotors to move a given amount of fluid through the pump chamber with each stroke of a piston or rotation of the rotors
Which type of pump is referred to as a “constant flow machine”
Positive displacement pumps
What are three characteristics of positive displacement pumps
pg 295
Self priming
deliver a definite volume of water or air
exhaust air from pump deliver water
define piston pump
pg 296
Type of positive displacement pump using one or more reciprocating pistons to force water from the pump chambers
define rotary pumps
page 296
Simplest of all fire pumps small capacity low volume high-pressure or priming driven by electric motor or clutch
What are two types of rotary pumps
page 296
rotary gear
rotary vane
define rotary gear pump
page 296
two gears rotating a tightly messed pattern inside a water tight case
amount of water pumped depends on size of the pockets in the gears and speed rotation
define rotary vane pump
page 298
positive displacement pump using hydraulic systems a rotor with attached veins is mounted off center inside a pump housing pressure is imported on the water as a space between the rotor and pomp housing wall decreases. shelf adjusts with wear
most common type used in centrifugal fire pump primers

define centrifugal pump
page 298
non-positive displacement Pump with one or more impellers that rotate and utilize the centrifugal force to move water most modern pumps are this type
define impeller
page 299
Vained circulating member of the centripical pump that acts as the disc receiving water through the eye in a center transmits motion to water resulting in velocity
It’s speed determines the extent to which water may overcome the force of gravity
define volute
page 299
spiral divergent chamber which receives velocity energy of the water by the impeller and converts it to pressure
what three factors influences a centrival fire pumps discharge pressure
page 300
Amount of water being discharged
speed at which the impeller is turning
pressure of water when it enters a pump from a pressurize source (hydrant relay etc.)
define single stage centrifugal pump
page 300
Single impeller
maybe; front mount, PTO, auxiliary or midship
Flow capacity up to 2250 GPM
define multistage centrifugal pump
page 301
A pump with an impeller for each stage mounted in a single housing impeller is may be a denticle the same capacity on a single shaft capable of connecting and series or in parallel
define pumping in parallel
(volume position)
page 301
Total amount of water the pump can deliver is equal to the sum of all the impellers operating in stages together
Define pumping and series
(pressure position)
page 302
when transfer valve is set in pressure position all water from intake manifold is directed into the eye of the first impeller, The second impellar further increase pressure in delivers water a higher pressure into the discharge port
At what percent range is the first impeller increase pressure a discharge when pumping and series
page 302
50-70%
if there’s any doubt as to whether or not to operate and pressure or volume which should a driver operator choose
page 303
Volume (parallel mode)
the pump will be cable supplying 100% but really capacity at 150 psi at 10 feet of lift with 20 feet of suction hose while drafting
Power operated transfer valves may operate at pressures has high as what?
page 303
200 psi
The opening between the pump casing in the hub of the impeller is usually limited to what?
page 304
.01”, Any increase lessons the effectiveness of the pump
define wear rings
page 304
replaceable rings are attached to the impeller indoor pump casing to allow us all running clearance between impeller and pump casing without causing wear of either
to maintain the preferred spacing instead of replacing the entire pump
Which type of seal is the most common type used today to prevent air leaks between the shaft and the pump casing Because it requires no adjustment but does require operation of the pump regularly
page 306
Mechanical seals
what is the most common type of seal packing material?
page 306
Rope fibers impregnated with graphite or lead
what are packing rings
page 306
Primarily use on older fire pumps they wear with the operation of the shaft and can be tightened to address leaks
what type of seal offered superior resistance to warping stretching and corrosion
page 307
ceramic
Unlike centrifugal pumps positive displacement pumps can do what
3rd Ed page 296
Pump air
what provides for the movement of water through a piston positive displacement pump
3rd ed page 296
A piston that moves back-and-forth or upper down inside a cylinder
The output of the Piston positive displacement pump is determined by the size of the cylinder and what
2nd page 267
Speed of the piston travel
The capacity of a piston positive displacement pump it’s usually determined by the size of what
2nd page 267
cylinder
The rotary gear pump consists of what
3rd page 296
To gears that rotate in a totally messed pattern inside a watertight case
The total amount of water that can be pumped by a rotary gear pump depends on the size of the —— and the speed of rotation
3rd page 297
pockets in the gears
which of the following is one of the most common types of pumps used to prime centrifugal pumps
3rd page 298
Rotary vane pump
in a rotary vane pump how is the rotor mounted
3rd page 298
off center
The centrifugal pump imparts —— to the water and converts it to pressure within the pump itself
3rd page 298
velocity
The operation of a centrifugal pump is based on the principle that….
3rd page 299
revolving disc throws water introduced at its center toward the outer edge of the desk
The ——- of a centrifugal pump transmits energy in the form of velocity to the water
3rd page 299
impeller
The —— of the centrifugal pump collects the water & confines it, in order to convert the velocity to pressure
the casing
The —— of the centrifical pump is a water passage that gradually increases in cross-sectional area as it nears the pump discharge outlet
3rd page 299
volute
which three factors influence a centrifugal fire pumps discharge pressure
3rd page 300
Amount of water being discharged
speed at which the impeller is turning
pressure of water when it enters the pump from a pressurized source
Which centrifugal fire pumps impellers are capable of delivering the rated pressure while supplying 50% of the rated capacity, so that the total amount of water the pump can deliver is equal to the sum of each stage
3rd page 301
Multi stage centrifugal pump in the parallel position
what centrifugal pump works by directing all water from the manifold into the eye of the first impeller increasing the pressure and discharging 50 to 70% of the volume capacity through the transfer valve and into the eye of the second impeller
3rd page 302
Multistage centrifugal pump and series position
define changeover
3rd page 302
Process of switching between pressure and volume position
Most manufactures specify that the pump may remain in the pressure system until it is necessary to flow more than ——- of the rated volume capacity
2nd 275
1/2
packing rings are used to make a seal at the point where the shaft passes through what
3rd page 306
Pump casing
As packing rings wear with the operation of the shaft, the ——- can be tightened and the leak controlled
3rd page 306
Packing gland
what are supplied to provide Cooling and lubrication between the packing rings and shaft
3rd page 306
Lantern rings
Pumps equipped with —— will not drip and will not require adjustment
2nd 280
Mechanical seals
piping systems must be able to withstand a hydrostatic test of —— before being placed in service
3rd page 312
500 psi
tank to pump piping should be sized so that pumpers with a capacity of 500 GPM or less should be capable of flowing —— GPM from the booster tank
3rd page 312
250 gpm
Tank to pump piping should be sized so that pumpers with a capacity greater than 500 GPM should be capable flowing at least ——- GPM from the booster tank
3rd page 312
500
According to NF PA 1901, enough
2 1/2 inch or larger diameter outlets must be provided in order to flow what
3rd page 314
The rated capacity of the pump
all discharge valves should be designed so that they are easily operable at pressures up to what
3rd page 314
250 psi
Valves control most of the ——-lines from the pump
3rd page 316
intake & discharge
what type of valve permits full flow through the lines with a minimum of friction loss
3rd page 316
ball type
Gate valves are most often operated by what
3rd page 317
handwheel
butterfly valves are most often operated by what
3rd page 317
1/4 turn valve
automatic pressure control devices must not allow the pressure to exceed ——- psi above the set level
3rd page 319
30
which types of automatic pressure control devices are sensitive to pressure change and have the ability to relieve excessive pressure within the pump discharge
3rd page 319
Discharge pressure relief valves
which types of automatic pressure control devices are intended to reduce the possibility of damage to the pump and discharge hose lines caused by water hammer
3rd page 320
Intake pressure relief valves
which type of automatic pressure control devices use a pressure sensing element connected to the discharge manifold to control the action of the electronic pump amplified that compares pump pressure to electrical reference point
3rd page 321
Electronic governors
which type of automatic pressure control device relieves excessive pressure that is generally caused by shutting down one or more operating hose line
3rd page 321
Electronic governors
Which type of automatic pressure control device has an adjustable spring loaded pilot valve that acts as a relief valve to bypass water from the discharge to the intake chamber of the pump
3rd page 319
Intake pressure relief valves
which type of primer uses an oil supply or some other type of fluid to seal the gaps between the gears and the case and to act as a preservative and minimize deterioration
3rd page 322
Positive displacement primers
which type of primer is environmentally friendly and does not require lubrication
3rd page 323
Oil less primers
Which type of primer requires that any air leaks In the pump be kept an absolute minimum and it’s suction hose in gaskets be kept in good condition
2nd page 300
exhaust primers
which type of primer primes the pump by connecting a line from the intake manifold of the engine to the intake of the fire pump with a valve connected in the line to control it
3rd page 323
Vacuum primers
which pump panel instrument provides an indication of the vacuum present at the intake of a pump during priming
3rd page 324
Master Intake gauge
midship pumps may be operated by either a series of gears or what
3rd page 309
drive chain or belt
in mid ship mount pumps the gear ratio is set so that the rotation required for the impeller to deliver a rated capacity of the pump is usually how many times faster than the engine itself
3rd page 310
1.5 to 2.5
What two factors affect the maximum capacity that can be obtained from a midship pump
3rd page 310
Engine horsepower and size of the pump
Some pumps may deliver 500 to 2250 GPM
With the engine idling in the pump engaged most speedometers will indicate between —— to —— mph
3rd 310
10-15
Rear mount pumps
Better weight distribution in compartment space
Expose drivers on coming traffic
Maybe powered by split shift or PTO
many pumpers are equipped with tank to pump piping as large as —— inches in diameter
3rd 312
4”
where is the primer tapped into the pump
3rd 313
High Point on the suction side of the impeller Eye
intake lines are located where in relationship to the pump above below or in line with
3rd 313
below
What is the shape of the primary intake piping next to the fire pump
3rd 314
Becomes Square in shape near pump to eliminate the vortex which may occur in water that flows through circular piping
Pumps rated greater than —— GPM capacity may require more than one large intake connection at each location
3rd 314
1500
According to NFPA 1901, fire apparatus with a rated pump capacity of 750 GPM or more must be equipped with how many 2 1/2 inch discharges
3rd 314
2
According to NFPA 1901 fire apparatus with a rated pump capacity of less than 750 GPM are required to have how many 2 1/2 inch discharges
3rd 314
1
Discharges greater than ——- inches in diameter may not be located on the pump operators panel
2.5”
What size discharge piping & valves must be used to supply discharges of one and a half to 2 inch hand lines
3rd 314
2”
According to NFPA 1901 apparatus equipped with tanks less than 1000 gallons must have a tank fill line of at least —— inches in diameter
3rd 317
1
what is the most common actuator for ball type valves
3rd 316
Push pull handles or quarter turn handles
NF PA 1901 require all intakes or discharges that are ——- inches or greater in diameter to be equipped with slow acting valve controls
3rd 317
3”
NFPA 1901 requires pressure control devices to operate within how many seconds after the discharge pressure rises and restricts the pressure
3rd 318
3-10 seconds
NFPA 1901 requires a pressure control device to operate when it discharge pressure rises and restricts the pressure from exceeding —- psi above set level
3rd 319
30 psi
Define discharge relief valve
3rd 319
Valve controls pressure that is delivered to the hose line nozzle from the pump
define intake relief valve
3rd 319
Adjustable spring loaded pilot valve bypasses water from the discharge and a chamber of the pump permitting the pump to continue operation when pressure rises above working or set pressure
it is generally recommended that when using add-on intake pressure relief valves, they be set to open with the intake pressure rises more than —— PSI of necessary operating pressure
3rd 320
10
Define pressure governor
3rd page 321
Pressure control device controlling engine speed in eliminating hazardous conditions resulting from excessive pressure
When drafting or pumping from the tank, the closed (draft) position is used. therefore water returns to the —- side of the pump
3rd 321
intake
when pumping from a hydrant and in the hydrant (open) position is used so that the water is discharged where?
3rd 321
the ground
 What is the most popular method to power a rotary vein priming pump?
3rd 322
electric motor
What is the purpose of using an oil supply for conventional primer pumps
3rd 322
The thin film of oil draws into the pump and seals gaps between gears in the case
The oil fills and irregularities in the housing caused by sediment or debris
generally speaking what is the ideal engine speed for priming
3rd 322
1000-1200 rpm
When the vacuum reading on a master intake gauge approaches ——- inches the pump is nearing its capacity, and is not able to supply additional lines
3rd 325
20”
Define voltmeter
3rd 326
Device used for measuring existing voltage in electrical system specifically battery condition
define ammeter
3rd 326
gauge Indicating both the amount of electrical current being drawn from and provided to the vehicles battery. good indication of the status of the vehicles alternator and charging system
auxillary “marine type” cooling device
Auxiliary cooling device that is inserted into one of the hoses used in the engine cooling system so that the engine coolant must travel through it as it circulates through the system.
features small tubes surrounded by water jacket connected to the discharge of the fire pump
immersion type auxiliary cooling device
3rd 329
Auxiliary cooling device directing water supplied by the fire pump to pass through a coil or tubing mounted inside the cooler to the path so that it is immersed in the coolant
