Chapter 10 Flashcards
Chapter 10
The driver operator must first made the pump operational and then prepare to use?
At least one of the three sources of water to supply the pumping operation (335)
When making a fire pump operational begins?
After the Apparatus is properly position and the parking brake has been set
how to prevent pump from over heating
circulator bypass or booster cooling valve to recirculate water back in the tank (337-38)
During drafting operations, the amount of friction loss is____to the amount of water moving through the hose or appliance
Proportional
pumping at a low residual pressure while being supplied by another apparatus is____ dangerous. This may cause the ____ to____,interrupting the supply of water. it may also lead to______of the pump
equally/hose /collapse,/cavitation
Transfer valve must be in parallel (volume)position when priming:(358)
Two-stage pumps
A pump in series (pressure) position may(358)
Trap air that will need to be removed
To create an effective fire stream during drafting operations,a lift of no greater than____ is recommended
20 feet for 60% capacity of the pump
As air is evacuated from the pump the compound gauge on the intake will register a vacuum reading
1 inch of mercury for 1 foot of lift required
Priming typically take 10 to 15 seconds but not to exceed
30 seconds (45 seconds in pump larger than 1250 GPM)
Vacuum is measured from the surface of the water
To the eye of the pump’s impeller
When opening the discharge (using a draft)if the pressure dropped below____pause a moment to allow it to stabilize before opening it further
50psi
Water temperature below 35°F or above 90°F may adversely impact The ability of the pump to reach (356)
Capacity
Driver engineer should maintain the residual pressure of at least ____ on their master gauge intake during pumping operation (340)
20 PSI
When using 2 1/2 or 3 inch to supply the pumper off the hydrant the lines should be(344)
Kept as short as possible to avoid excess friction loss
When pumping in relay the supplying pumper should supply
20 psi plus friction loss and engine pressure should not exceed 250 psi
If a circular tank is 12 feet in diameter 15 feet high is 3/4 full and water is being removed from the tank at a rate of 500 GPM, approximately how many minutes will it takes before the tank is empty
x
Class AA hydrant
Light blue at 1500 gallons per minute
Class A hydrant
Green at 1000 to 1499 gallons per minute
Class B hydrant
Orange at 500 to 999 gallons per minute
Class C hydrant
Red at less than 500 gallons per minute
The water supply from an onboard water tank is(336)
The sole source of supply for many incidents
The two basic pressurized water supply sources are a fire hydrant and(339)
Supply hose from another pumper.
In order to partially open the tank fill valve and not create the potential for pump cavitation, some driver open the valve the distance of their thump to the pump panel with their hand on the valve control.(338)
True.
As the discharge volume from the fire pump increases,(339)
the incoming pressure from the supply source may drop due to friction lost in the water system
If discharge flow volume is increased too much when operating from a pressurized water source(339)
Intake pressure from the supply source may be reduced to a point that may damage the pump
During pumping operations, driver/operators should maintain a residual pressure on the master intake gauge: (340)
Of at least 20psi
Hydrants served by large mains that are in the interconnected in a grid pattern receive their supply(340)
From several directions and usually have lesser amount of segmentation and deterioration
The least desirable hydrant are those located on(340)
“Dead end mains”that are served by smaller mains from only one direction.
Dead end mains hydrants generally have(340)
Higher amounts of sediments and deterioration,which further reduce their capacity
A pumper may need to be placed at the hydrant to make use of all available pressure
In a long lay with large flow demands
Which of the following is the purpose of a four-way hydrant valve in making a lay? (341)
Allows a second arriving pumper to be connected without
interrupting the flow of water to the original supply line
Which of the following consists of laying hose from the fire to the water source? (344)
Reverse lay
Which of the following would be used when the driver/operator first reports to an incident location in order to size up the scene before laying a supply line? (344)
Reverse lay
executing a reverse lay is a common method for setting up water supply operation relay pumping operation using ______as a supply line(344)
medium diameter hose
the reverse lay is the most direct method of supplementing____ ____ or performing_____ _____(344)
hydrant pressure/drafting operation
When a pumper is connected to hydrant and not discharging water, the pressure show on the intake gauge is
static pressure
the driver should close the tank to pump valve after transition to
an external water supply
When the pump is discharging water, the intake gauge display the
Residual pressure
The difference between the static pressure and a residual pressure
Determine how much more water the hydrant can supply
The amount of friction loss in the intake hose depends on
The diameter and length of the hose as well as the intake strainer and any adapters in use
During drafting operations,the ability to overcome losses in pressure is
Limited to atmospheric pressure at sea level
With the pump moving water, the vacuum reading on the master intake gauge will provide an indication of
The remaining capacity of the pump
Most pumps are able to develop a vacuum capacity of approximately
22” of mercury
During cavitation, the pressure drops below atmospheric and
The boiling point of water drops to the point that the water changes to a vapor and creates a void composed of water vapor,steam
The temperature of the water, the height of the lift,and the amount of water to be discharged.
Affect the point at which cavitation begins
What are some indication that pump is cavitating
1•The pressure gauge on the pump well fluctuate and hose streams may pulsate creating a distinctive sound as the water leaves the nozzle.
2• (severe case)noise from the pump sounding
gravel passing through the pump
3• (surest indication) lack of reaction on the
pressure gauge to increases in the throttle
Water temperature will also affect drafting operations
True
Water below _____ or___may adversely impact the ability of the pump to reach capacity
35°F or above 90°F
All fire pumps meeting NFPA and underwriter’s Laboratories Inc. requirements are rated to pump
The capacity at 10’ of lift
if the lift is less
the capacity of the pump is higher
If the lift is greater
The capacity city decreases
Pressure differential
x
A pumper in good working order I can lift water and a maximum of
25’
To create an effective fire stream
A lift of no greater than 20’ is recommended. With the pump operating at about 60% of it rated capacity
When priming the pump and beginning drafting operations, a two- stage pump: (358)
must have the transfer valve in the parallel (volume) position.
Most priming pumps are intended to work most effectively when the engine is set at
A rate between 1000-1200 rpm
If an Apparatus features a vacuum-primer, the engine RPM should be kept
As low as possible without causing the engine to stall
As the air is evaluated from the pump the master intake gauge will register
vacuum reading (should equal 1” of mercury for 1’ of lift required)
Vacuum is measured from the surface of the water
To the eye of the pump’s impeller
the most common cause of an inability to prime? (359)
An air leak that prevents primer from developing enough vacuum to successfully draft water
The most common cause of an air leak is
Open drain or valve
The entire priming action typically requires 10-15 seconds. However,when up to 20 feet of intake hose lifting a maximum of 10 vertical feet,
It may take as long as 30 seconds (45 seconds in pumps larger than 1250 gpm)
After successfully priming the pump, the throttle setting should:
slowly be increased before attempting to open any discharges.
Open the desire discharge valve slowly while observing the discharge pressure
True
If the pressure drops below 50 psi
Pause for a brief time to allow it to stabilize before opening the valve further
Opening the valve too quickly may cause
Air to enter the pump causing a loss of prime
The driver/operator should not attempt to set the discharge pressure to the desire value
Until water is flowing and the gauge is stabilized
Once the desired pressure has been established and the hoselines are in service
Set the relief valve or pressure governor
The most common source of problem while operating at draft
Air leak on the intake side of the pump
If the discharge pressure gauge begins to fluctuate with corresponding loss of vacuum on the intake gauge,
Air is most likely coming into the pump along with the water. (Couplings should be re-check for tightness)
If there is not enough water above the drafting strainer
A Whirlpool may be allowing air to enter the pump.
If the onboard tank is empty
The tank to pump line may be a source of leakage
While the pump is operating, a gradual increase in the vacuum maybe noted with no change in the flow rates
This is an indication that a blockage is developing
After a pump has been operating at high rate of discharge
A blockage often occurs
The most common place for a blockage to occur is
In the strainer
Blockage may also occur against the strainer located at the intake of the pump
In this case, the pumping in operations must be discontinued while the intake hose is removed to access and clear the strainer
After the pump has been drained and the connections removed
Operate the positive displacement primer for several second until primer oil or fluid comes out of the discharge from the priming pump
When shutting down the drafting operation, why should the positive displacement primer be operated for several seconds until primer oil or fluid comes out of discharge from the priming pump
Aids in lubrication of priming pump
The automatic water supply for sprinkler system is designed to supply only
A fraction number of the total fire sprinklers at any given time
fire department connection may consist of a Siamese with at least
Two 2 1/2 inch female connections connected to a clapper Inlet, or one larger diameter sexless connection
Wet standpipe system that contain water on the pressure
May be used as soon as the hose line is stretched and the valve opened
Generally friction loss in the standpipe is small unless the flow is very large
True
Do not use pump discharge pressure in excess of 185 psi
Unless the standpipe system, hoses,and appliances has been designed to function under high-pressure
For each floor above the fire department connections that will have operating fire streams
Add approximately 5 psi
When a standpipe system is known to be equipped with pressure reducing valve
The elevation pressure used must be based on the total height of the standpipe or zone being used
When a dry standpipe system is charged, water will be discharged: (365)
at all points where caps are off and valve is open
the most likely scenario if a supply line that was charged suddenly loses water
The supply line has burst
The most likely scenario if a supply line loses water but the supply line is intact
The hydrant or water main has failed
All pumps meeting NFPA and Underwriters Laboratories Inc. requirements are rated to pump their capacity at
10 feet of lift
If the lift is _____, the _____, of the pump is highter; if the lift is _____, the capacity _____.
less, capacity, greater, decreases
Pumper in good working order can lift water a maximum of _____. However,all available atmospheric pressure is required to overcome this lift. Making the remaining ______of the pump of little value for fire suppression
25 feet,capacity
To create an effective fire stream during drafting operations,a lift of no greater than____ is recommended
20 feet for 60% capacity of the pump
As air is evacuated from the pump the compound gauge on the intake will register a vacuum reading
1 inch of mercury for 1 foot of lift required
The ability to overcome losses in pressure is limited to atmospheric pressure at _____. This pressure decreases approximately _____ or 1 inch of Hg for each _____ of alitude gain.
sea level (14,7 psi) 0.5 psi, 1,000 feet
