DPO Flashcards
Finish Mechanical Foam is a….
Completed product after air is introduced in the solution and leaves the nozzle
The purpose of the check valve in a fire department connection is to prevent…
Water from a sprinkler system from flowing back
Pump discharge pressures should not exceed ___psi unless the standpipe system has been designed to withstand higher pressures
185psi
Which type of fire pumps must be primed using an external priming device?
Centrifugal
Once the power take-off has been properly activated and the pump is engaged, the vehicle speedometer should show a speed of….
Slightly above 0 mph
A___distribution system is a network of water mains which provides circulating feed
Grid
Using the coefficient method, determine the pressure loss due to friction in the hose assembly
86.5 psi
Fire gels work by….
Entrapping water instead of air
A hydrant with the largest capacity will be one that is connected to a …..
Primary feeder
One method of calculating the capacity of a water shuttle operation in gpm is…..
Travel time divided by the required flow
The amount of work that a pump must do to produce a fire stream is the _____pressure
Pump Discharge
If a fire department connection is found inoperable, the best way to bypass it so operations can be performed is….
Stretch a medium size diameter supply line into the building and connect it to the standpipe hose outlet on the first floor
A dual pumping operation is…..
Placing one pumper at a hydrant and a second pumper connected intake to intake
Water flowing through hoses and appliances results in….
Friction Loss
Water temperature greater than 90 degrees F can cause _____in the fire pump
Decreased capacity
In a _______hydrant, a small drain valve opens as the hydrant is closed
Dry barrel
A piercing nozzle would be used on……
An attic fire
In-line relay valves allow for…..
Late arriving pumpers to hook up without interrupting operations
TO prevent water hammer, it is important to close nozzles, hydrants, valves, and hose clamps……
Slowly
An operator should prime a pump when operating…..
From a static source
When performing a capacity test, the desired net pump pressure should be _____psi
150 psi
The process that causes foam concentrate to move through an in-line foam eductor and into the water stream is the _____principle
Venturi
A _____depends on an external water source to provide the water
Dry Standpipe System
You should switch from pressure to volume when…..
More than half of the rated capacity of the pump will be required.
Compressed air form systems result in…..
Greater reach of fire stream
The selection of a proportioner depends on…..
Required ratio of foam and length and size of the attack line
The flow from a 1-inch nozzle tip with nozzle pressure of 50 psi is approximately ____gpm
210 gpm
To reduce carcinogen exposure after a fire, you should…..
Transport contaminated gear way from passenger compartments
All gauges used for service tests must have been calibrated within _____days
60
Pump discharge pressure is equal to…..
NP + TPL
_____ is a force-per-unit area with the measurements of force in pounds and the measurement of area in square inches
Pressure
Relay Operations should be shut down from the _____first
Attack pumper
Discharge manifolds may be used in relay operations to ……
Support more than one attack pumper
The pressure remaining once water has begun flowing is ______ pressure
Residual
Which is a fire hose appliance carried on a fire apparatus
Gated wye
The 50 percent pump capacity test is conducted at a net pump pressure of…..
250 psi for 10 minutes
Which valve determines whether the pump is operating in series or pressure mode
Transfer valve
Which foam has a surfactant added that it makes more fluid
Fluoroprotien
One way to increase the efficiency of water shuttle operations is to ….
Decrease the time required to fill the tender
An increase in vacuum while drafting indicates a……
Clogged strainer
During a water shuttle operation requiring two pumpers, the pumper located near the emergency scene is the…..
Dump site pumper
The recommended nozzle pressure for smooth bore master streams is _____psi
80
A common reason for eductor failure is……
Improper cleaning and maintenance
When pumping from a tank and attack lines are being used intermittently, which is a way the pump operator can ensure the pump does not overheat
Set the circulator valve to tank position
When positioning a pumper to supply a fire department connection, the apparatus operator must consider the……
Positioning requirements of the other apparatus
Which type of pump may be used as the priming pump of a centrifugal pump?
Rotary vane
While transferring water from one dump tank to another, which method is most effective?
Jet siphon
An operator obtains a reading of 17 inches of mercury on the intake gauge while drafting and flowing water. This indicates….
A lift of approximately 19 feet
Theoretically, the maximum distance a pump can lift water at sea level is _____ feet
33.9
High energy foam systems introduce…..
Compressed air into the foam solution prior to discharge into the hose line
The recommended nozzle pressure of 2 1/2” hand lines with solid bore tips is ____ psi
50
Hose that is laid from the fire to the hydrant is considered a ……
Reverse lay
Discharge manifolds may be used in relay operations to……
Support more than one attack pumper
Available flow from hydrants is estimated by determining the percent drop between the static and _____pressures
Residual
Fire pumpers must carry one straight ladder, one extension ladder, and…….
An attic ladder
Nozzle reaction is explained by the law of physics that states…..
For every action there is an equal and opposite reaction
For drafting purposes, lift is measured from the….
Surface of the water to the pump intake
Which statement about foam is true
IT works by separating, cooling, or suppressing
A 2,000 gallon tender makes the round trip between the dump site and fill site in 12 minutes. The flow rating for that tender is ______ gpm
150
A relief valve by-passes excess water from the discharge side of the pump to the____
Pump intake
The residual pressure reading at the intake gauge in a relay pumping operation should stay above ____psi to prevent damage to the pump
20
A _____ indicates flow in gallons per minute
Flow meter
What is the approximate pump discharge pressure necessary to deliver 600gpm through a fog nozzle on deck gun using (3) 2 1/2” lines? The lines are 400’ long and the deck gun is elevated 20 feet above the pumper (Deck gun FL= 10 psi)
150
When color coding fire hydrants, what color will the bonnet be on a hydrant rate to flow 750 gpm
Orange
_____ pressure is the difference between the pump discharge pressure and the incoming pressure from the hydrant
Net pump discharge
When a pumper is supplying four lines of 2 1/2” hose, each equipped with a 250gpm fog nozzle at 100 psi and each 300 feet long, what is the discharge pressure
138psi
A distributor nozzle could be used on
An attic fire
When using foam to extinguish a fire, the suppressing method
Prevents the release of flammable vapors
The minimum depth of water required to pull a draft using a barrel strainer is
4 feet
Which is a fire hose appliance carried on a pumper?
Gated Wye
What would be a common problem when looking at a static water source for drafting?
Accessibility
The friction loss in 300’ of 3” fire hose with 2 1/2” couplings flowing 500 gpm is approximately
60 psi
When priming a pump, it is necessary to….
Make the pump as air tight as possible
____ consist of a return water line connected from the discharge side of the pump back tot he intake side of the pump
Around the pump proportioners
What is the flow from a 2” nozzle with ideal nozzle pressure? (gpm=29.7 x d2 x sq rt NP)
1063gpm
The actual maximum height to which water will be lifted when the intake gauge reads 9” of mercury is ______ feet
10.17
Which is a feature of a wet barrel hydrant
Does not require draining after use
The spiral chamber of a centrifugal pump in which the velocity given to water by the impeller is converted into pressure is the……
Volute
The kinds of liquids that are lighter than water are those with a specific gravity
Less than 1
What is the friction loss in 300” of 2 1/2” rubber lined hose flowing 350 gpm
74 psi
Using the hand method, determine the pumps discharge pressure required to supply the hose assembly…..
150 psi
______ are controlled by monitoring the water flow and controlling the speed of a positive displacement foam concentrate pump
Variable-flow, variable-rate direct injection systems
The theoretical lift for a pump at sea level is _____feet
33.9
Using an in-line eductor, the back pressure must not exceed _______ pressure
70% of the inlet
In relay pumping operations, the ______should be positioned nearest the water source
Largest capacity pumper
The total friction loss in 500’ of 3” hose with 2 1/2” couplings with 300 gpm flowing is approx
36 psi
When calculating the time for a shuttle operation, timing starts when the
Dump valve is opened on the tanker
In a water distribution grid, the _____supplies individual hydrants
Distributor
Each fire pump impeller in a housing is a
Stage
The collapse zone of a building should be ______ the structure
One and a half times the height
The recommended pressure for standard fog nozzles is
100 psi
During an extended period of pumping, a gradual increase in engine temperature is noted. A step to reduce this condition would be
Open aux cooler
When using foam to extinguish a fire, the cooling method
REduces the temperature of the fuel and adjacent surfaces
If the friction loss is 300 feet of hose at 70 psi, what will the friction loss be in 650 feet of the same size hose flowing the same amount of water?
105 psi
Centrifugal fire pumps may make use of
Positive intake pressures
PDP is equal to
NP + FL
Pressure control devices must operate within _____ with an increase of 30 psi
3-10 seconds
Which primer utilizes the venturi principle
Exhaust primer
Apparatus equipped with water tanks larger than 500 gallons must provide a tank-to-pump flow rate of ______ gpm
500
What is a characteristic of dry hydrants
Found near lakes or rivers
