Pump Ops Chpt 9 Flashcards
Although no longer used as high capacity pumps, some are still in service for high pressure stream fire fighting. These multi cylinder pro driven pumps can provide pressures up to 1000 psi for high pressure fog lines, or to inject foam concentrate into water line or manifold at higher pressure than the water is creating.
Piston pumps
From a stand point of design, Rotary type pumps are the simplest of all fire apparatus pumps
Rotary pumps
Rotary gear pumps consist of two gears that rotate in a tightly meshed pattern inside a water tight case
Rotary gear pumps
Are constructed with moveable elements that automatically compensate for wear, maintaining a tighter fit with closer clearances as the pump is used.
Rotary vane pumps
In a ________, the rotor is mounted off center inside the housing. The distance between the rotor and the housing is much greater at the intake than at the discharge
Rotary vane pump
Nearly all modern fire apparatus feature a _____ as their main pump. This pump is classified as a nonpostive displacement as it does not pump a definite amount of water with each revolution.
Centrifugal pump
The operation of a ______ 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.
Centrifugal pump
The_________ acts as a disk receiving its water through the eye in its center.
Impeller
The _______ transmits energy in the form of velocity to the the water.
Impeller
The ______ houses the impeller assembly, collects the water, and confines it in order to convert the velocity to pressure
Pump casing
The off center mounting of the impeller within the casing creates a water passage of gradually increasing size as it nears the discharge outlet of the pump. This section of the pump is called the _______.
Volute
Pumps used in the fire service constructed with a single impeller are referred to as a ________.
Single stage centrifugal pumps
These may consist of front mount pumps, power takeoff, auxiliary engine driven, and midship pumps they use a single intake impeller and a simple casing to provide flow capacities up to 2,250 gpm(9000L/min).
Single stage centrifugal pumps
To minimize the lateral thrust of large quantities of water entering the eye of the impeller, a ________ may be used. The _______ takes the water in from both sides; the reaction of each side being equal and opposite cancels out the lateral thrust.
Double-suction impeller
_____ have an impeller for each stage mounted in a single housing
Multistage centrifugal pump
If a two stage pump is rated at 1000 psi, each impeller supplies ______ to the pump discharge manifold. At that point, the two streams combine to create 1000 gpm available to the the discharges at a net pressure of 150 psi.
500 psi
When the transfer valve is set in the _______, all the water from the intake manifold is directed into the eye of the first impeller.
Pressure position
Setting the transfer valve to ______ greatly increases the maximum pressure that may be attained; however, increasing the pressure results in a corresponding loss in volume.
Series (pressure)
The process of switching between pressure and volume is sometimes referred to as “________.”
Changeover
If there is any question as to the correct position for the transfer valve, it is best to operate in ________ rather than series (pressure).
Parallel (volume)
In the _______, the pump will be capable of supplying 100 percent of its rated capacity at 150 psi at 10 feet of lift with 20 feet of suction hose while drafting.
Parallel mode
Newer pumps use a _______. This valve may be activated by electricity, air pressure, or by water pressure itself. Many ______ operate at pressures as high as 200 psi.
Power operated transfer valve
Are essential to the operation of a multistage pump. Should a valve stick open or closed, or be hampered by debris, the pump will not operate.
Clapper check valves
The pressure in the Volute is much higher than that in the intake side of the pump at the eye of the impeller. A very close tolerance must be maintained between the pump casing and the hub of the impeller. This opening is usually limited to _____ or less.
.01 inch (0.25)
To restore the pumping capacity without replacing the entire pump, _____ or clearance rings in the pump casing may be replaced to maintain the preferred spacing between the hub of the impeller and the pump casing.
Wear rings
The most common type of seal packing material is composed of rope fibers impregnated with ______ or ____.
Graphite or lead
Pumps powered by gasoline or Diesel engines independent of the vehicle drive engine are examples of ______.
Auxiliary pumps
Mechanism that allows a vehicle engine to power equipment such as a pump, winch, or portable tool; it is typically attached to the transmission
PTO power takeoff drive
I the past, conventional PTO units were limited to pouring pumps up to approximately 500 gpm. However, some manufacturing now provide full torque_____ that allow for the installation of pumps as large as 1,250 gpm.
Full torque power takeoffs PTOs
To use a ______, the chassis should have a front of engine PTO option that provides a coupling to the front of the crankshaft.
Front-mount pump
The driver/operator may check to see that the transmission is in the correct gear by observing the speedometer reading after the pump is engaged. With the engine idling and the pump engaged, most speedometers will indicate between ____ to ____.
10 to 15 mph
The piping system and the fire pump itself must be capable of withstanding a ______ before being paced into service.
Hydrostatic test of 500 psi
According to NFPA 1901 pumpers with a capacity of 500 gpm or less should have piping capable of flowing ______. Pumpers with a capacity greater than 500 gpm should be able to flow at least _____.
250 gpm
500 gpm
A minimum of _____ piping, valves, and elbows must be used to supply discharges where 11/2-, 13/4-, or 2-inch handlines are attached .
2 inch
All valves should be designed and maintained so that they are easily operable at pressures of unto ______.
250 psi
According to NFPA 1901, apparatus equipped with tanks of less than 1000 gallons must have a tank fill line of at least_____ in diameter.
1 inch
Tanks greater than 1000 gallons must be provided with at least a _______ tank fill line.
2 inch
The most common type of valve is the ____ that permits the full flow of water through a line with a minimum friction loss.
Ball type valve
Are most commonly operated by a hand wheel
Gate valves
NFPA 1901 requires some type of pressure control device to be part of any fire apparatus pumping system. This device must operate within _____ to ____ seconds after discharge pressure rises and restricts the pressure from exceeding 30 psi above the set level.
3 to 10 seconds
Although there are several types available, the most common relief valve uses a _________.
Spring-controlled valve
Is designed to regulate the engine speed to match the pump discharge requirements.
Pressure governor
The electronic governor also features ________ protection by returning the engine to idle when the intake pressure drops below 30 psi. These governors are accurate and quick to respond, eliminating the need for a discharge pressure relief valve.
Cavitation
These devices are constructed of materials that do not require lubrication; therefore, oil is not required in the priming process. ______ may slo be installed into an older apparatus as an environmentally friendly initiative.
Oil-less primers
Are generally found on skid mounted pumps or older fire apparatus. This type of primer uses the same principle as a foam eductor. Exhaust gases from the vehicles engine are prevented from escaping to the atmosphere by an exhaust deflector. These gases are diverted to a chamber where their passing velocity creates a vacuum
Exhaust primers
The ______ is a simple device that makes use of the vacuum already present in the intake manifold of any gasoline-driven engine.
Vacuum primer
An air priming system uses the compressor to supply an airline to a jet pump that creates a _______ that primes the pump using no mov g parts or lubricants
Venturi effect
The ____ is connected to the intake side of the pump and measures either positive pressure or a vacuum.
Master intake gauge
This gauge is usually calibrated from ___ to ___ psi of positive pressure and from ___ to ____ inches of mercury on the negative side.
O to 600 psi
0 to 30 inches
When the vacuum reading is approaching ____, the pump is nearing its capacity and is not able to supply additional lines
20 inches
The _____ displays the engine speed in revolutions per minute
Tachometer
The _______ displays the temperature of the coolant in the engine that powers the fire pump
Pumping engine plant temperature indicator
The pump operators’ panel may be equipped with an audible or visual indicator that warns the driver/operator when the pump will overheat.
Pump overheat indicator
The _____ provides a relative indication of the battery condition
Voltmeter
Indicates the status of the vehicles alternator and charging system
Ammeter
Pump pressure indicators, commonly called ______, may be connected to the individual discharge outlets of the fire pump. These gauges must be connected to the outlet side of the discharge valve so that the pressure being reported is the pressure actually supplied to the hose lines after the valve
Discharge gauges
This device is use to increase or decrease the speed of the engine that powers the fire pump. An increase or decrease in engine speed will allow the driver/operator to control the amount of pressure that the fire pump supplies to the discharge
Pumping engine throttle
The ______ is used to operate the priming device when the pump will draft from a static water supply
Primer control
This device displays the quantity of water held in the onboard water tank, allowing the driver/operator to anticipate the length of time attack hose lines may be operated until an external water source is needed
Water tank level indicator
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. The cooler features a number of small tubes surrounded by a water jacket that is connected to the discharge of the fire pump.
Marine cooler
In the _______, the water supplied by the fire pump passes through a coil or tubing mounted inside the cooler so that it is immersed in the coolant.
Immersion system
Are becoming an increasingly more popular method of priming pumps on modern fire apparatus
Air primers
This device is used to increase or decrease the speed of the engine that powers the fire pump. An increase or decrease in engine speed will allow the driver/operator to control the amount of pressure that the fire pump supplies to the discharge. There are several types of throttles available,including a throttle knob called a ______,that can be turned clockwise or counter clockwise to achieve required pressure
Vernier
Operate using a small piston that moves back and fourth in a cylinder
Piston pumps
Most of the rotary pumps in use today are either
Rotary gear or rotary vane construction
This is one of the most common types of pumps used to prime a centrifugal fire pump
Rotary vane pumps
Nearly all modern fire apparatus feature a ______ as their main pump
Centrifugal pump
Three main factors influence a centrifugal fire pump discharge pressure
Amount of water being discharged
Speed at which the impeller is turning
Pressure of water when it enters the pump from a pressurized source
Any ______ on the fireground must be carefully coordinated with attack crews so that they will be prepared for a slight interruption during transfer
Changeover
Newer model centrifugal pumps may be equipped with a ______ that opens to allow overheated water to circulate between the pump and the main tank or into the atmosphere
Thermal relief valve
Heat develops by friction where the packing rings come into to contact with the shaft. In order to overcome this a spacer, known as a _______ is supplied with the packing to provide cooling
Lantern or slinger ring
Are most common to initial attack, wild land, or mobile water supply applications
PTO driven fire pumps
In order to minimize pressure loss within the apparatus, all hoses and piping must be designed to
Run as straight as possible with a minimum number of bends or turns
On pumps not equipped with a ______ the tank fill line can be used in conjunction with the tank to pump valve to circulate water through the pump to prevent overheating when no water is flowing
Thermal relief valve
Some pumps are equipped with a ______ that serves the same function as a circulator valve by diverting a portion of the discharge water into the tank
Booster line cooling valve bypass valve
The most common actuators for ball type valves are either
Push pull handles or quarter turn handles
Are most commonly operated by quarter turn handles
Butterfly valves
NFPA 1901 requires that all intakes or discharges that are 3 inches or greater be equipped with
Slow acting valves
It is generally recommended that the intake relief valves be set to open when the intake pressure rises more than _____ above the necessary operating pressure
10 psi
Intake relief valves are intended to reduce the possibility of damage to the pump and discharge hoselines caused by _____ when valves or nozzles are closed too quickly
Water hammer
A _____ is needed to create the vacuum that makes drafting possible
Priming device
Most modern pumpers use
Positive displacement primers
Although some apparatus feature primers that are driven off the transfer case of the transmission, an ______ is the most popular means of powering rotary vane priming pumps as they may be operated efficiently regardless of engine speed
Electric motor
Because the oil reservoir for the priming pump is often mounted higher than the pump itself, a ______ is provided to break the siphon action as the tank drains
Vent hole
The operator manual supplied by the fire pump manufacturer should specify the preferred engine speed for priming but, in general, the range is between
1000 to 1200 rpm
Most new pumpers are equipped with
Oil less primers
Because engine vacuum is greatest at near idle speed, the primer works best at low engine rpm
Vacuum primers
Are becoming an increasingly more popular method of priming pumps on modern fire apparatus
Air primers
An _____ uses the compressor to supply an airline to a jet pump that creates a Venturi effect that primes the pump using no moving parts or lubricants
Air priming system
During _____, the rpm required to pump the rated capacity is determined and the information is recorded on an identification plate on the pump panel
Acceptance testing
The primary function of an ________ is to control the temperature coolant in the apparatus engine during pumping operations.
Auxiliary coolant system
