FIRE PUMP THEORY AND OPERATION Flashcards
Pages 20-29
Fire Pump Theory and Operation
JFRD engines are built by pierce and are fitted with midship mounted Waterous ____ ____.
These are either single-stage or two-stage and rated at _____, _____, or _____ GPM capacity.
Centrifugal pumps
1500, 1750, 2000
Fire Pump Theory and Operation
Even though the various pumps differ in appearance at the pump panel, they operate in a similar manner and share construction features. In simplest terms the modern fire pump has ____ primary sections.
which are?
Three
- Intake manifold
- Discharge manifold
- Centrifugal pump assembly
Fire Pump Theory Operation
JFRD engines are powered by six-cylinder turbo-charged diesel motors, manufactured by Caterpillar ( ___ or ___ ) or Cummins ( ____ ).
C12 or C13
ISL series
Centrifugal Pump Theory of Operation
The impeller discharges water into _____, the chamber which directs pressurized water into the discharge manifold.
As motor speed (RPM) increases, the _____ of the impeller(s) increase.
As water enters the impeller(s) at low pressure the centrifugal force of the rotating impeller(s) increases ____.
volute
velocity
pressure
Pump Shift
The pump shift control is a pneumatic switch located in the cab at the engineer position. There are 3 positions -____, ____, and ____.
ROAD, NEUTRAL, and PUMP
Pump Shift
The transfer case cannot engage both ____ and ____ simultaneously.
PUMP and ROAD
Pump Shift
The ____ position is used only in the event of failure with the pump shift requiring use of the manual pump shift control.
NEUTRAL
Two- Stage Pumps
In PRESSURE each impeller provides pressure in _____
series
Two-Stage Pumps
Utilize a ___ socket and socket wrench to change settings if the electric valve fails.
3/4
Two-Stage Pumps
In _____, the supply is divided, and water is routed to both impellers at the same time
Roughly ___% of the total pressure is produced by each impeller.
the VOLUME position is also called ____ or ____
VOLUME
50%
Parallel or capacity
Two-Stage Pumps
When pumping beyond 50% of a pumps rated capacity, you must be in ____.
VOLUME
Two-Stage Pumps
The normal position of the transfer valve is _____ which will produce maximum pump performance for the majority of pumping scenarios.
VOLUME
Single-Stage Pump
The main difference in operation from a two-stage pump is ____ ____. To pump high pressures the single stage pump requires higher ____.
A single stage pump will operate much like a two stage pump in _____.
motor speed
RPM
VOLUME
Intake Piping
Each steamer intake has installed a piston intake valve (PIV) or (BIV) intake valve. Both types of intake valves incorporate a ____ ____ valve, a ____-____ ____ ____ valve, a _____ valve to bleed air from the supplies hose, and a ___ ___ adapter.
The newer BIV is less ____ (allowing higher GPM) and is rated for ____
Water control valve
spring-operated pressure relief valve
bleeder valve
5” Storz
Restrictive
Drafting
Intake Piping
Both the internal pressure relief valve in PIV/BIV are preset to ___ ___
150 PSI
Intake Piping
The diameter of the intake pipe is determined by the ____ ____ of the pump.
All JFRD engines have ____ Steamer intakes which allow the pump to draw the rated capacity at draft through one steamer intake (_____ GPM) or both steamer intakes( _____ and ____ GPM).
Rated capacity
6”
1500 GPM
1750 and 2000 GPM
Intake Piping
The front and rear intake pipes are ___” in diameter and because of the reduced diameter will flow less than the steamers (____ GPM at Draft, ____GPM from a hydrant).
5”
1000 GPM “DRAFT”
1500 GPM “HYDRANT”
Intake Piping
____ and ____ have one additional intake inside the tailboard compartment. This intake is a direct tank fill and is painted ____ to distinguish it from the other connections.
E-7 and E-21
Red
Valves
The Electric front and rear intake valves take __-__ seconds to fully open or fully close.
15-20 seconds
Valves
The most commonly used valves are ____ ____ ____ and ____ ____.
The ____ ____ ____ valve allows booster tank water to be drawn into the pump to be pressurized and discharged.
Once hose lines are properly set and there is enough residual pressure, open the ____ ____ valve just enough to supply water to the tank without reducing residual pressure.
TANK TO PUMP and TANK FILL
TANK TO PUMP
TANK FILL
Discharging Piping
The master discharge gauge reads the ____ ____ ____ while the remote discharge gauges indicate pressure within the discharge ____ and ____ ____ only.
discharge manifold pressure
Piping and hose line
Gauge Construction
Each gauge is of the ____ type.
The pressure scale reads ____ PSI, and the vacuum scale reads ___ to ___ inches.
The threaded plugs in between are only used for ___ ___.
compound
0-600 PSI
0 to -30 inches
pump testing
Electric Primer
The electric primer is a ____ ____ pump driven by a small electric motor and activated by a ____ ____ on the pump panel.
Unlike the centrifugal fire pump, the primer is a ____ ____ ____ which can pump air and water.
When activated it creates a ____ within the fire pump, removing air so water can enter the pump.
Rotary vane
Pull handle
positive displacement pump
Vacuum
Pneumatic Primer
Newer engines utilize a ____ ____ activated by pressing a button on the pump panel.

pneumatic primer
Pneumatic Primer
If your primer is inoperative there are two alternative methods for bleeding air from the pump.
The ____ ____ discharge is the highest discharge on the pump and partially opening this valve will help purge air and prime the pump.
Small amounts of air can also be purged by partially opening the ___ ___ valve.
deck gun
TANK FILL
Pneumatic Primer
NOTE: both types of primer pumps draw current from the vehicle charging system. Although you can safely operate the primer at any pressure or RPM, for best performance set the RPM between
1000-1200
Motor Function Gauges
Oil pressure
15 PSI at idle
35-45 at speed
Motor Function Gauges
Coolant Temperature
180-220 degrees fully warmed up
Motor Function Gauges
Voltage
13 to 14.5 volts
Motor Function Gauges
Transmission Temperature
Under 300 degrees is normal
Pump Cooler/Recirculator
This valve controls a small discharge line that directs pump water to the ___ ___.
When opened it will flow less than ___ GPM and will remove hot pump water, to be replaced with cooler water from the supply.
If the pump is being supplied by a ____ or ____ in this valve is open, you will eventually overflow the booster tank.
This valve is generally only needed when ____ ____ are ____ but not ____.
booster tank
25 GPM
Tanker or hydrant
hose line are charged but not flowing
Engine Cooler or Auxiliary Cooler
This valve operates as a ___ ___.
To prevent overheating while the pump is operating open this valve to discharge cool pump water through the ____. 
Within the radiator is a coil of tubing and pump water flows through this coil to reduce the ____ ____.
Pump water in coolant never mix. This valve should be open anytime the current temperature exceeds the ____ ____.
The ____must be engaged for this valve to function. 
Heat exchanger
Radiator
Coolant temperature
Normal level
Pump
