12 - IFSTA Chapter 12 Flashcards
The need for relay pumping is determined by what?
The amount of water required at an incident
and
The distance between the incident scene and the water source.
Centrifugal pumps are rated to pump at their maximum volume capacity at draft at what PSI?
150 psi
Driver/operators as the relay pumper should maintain an intake pressure of what?
20 -30 psi
To establish a stable operating condition, attack pumpers equipped with an adjustable intake relief valve should set it to what psi?
50-75 psi
When the need for a relay pumping operation has ended, the operation should be discontinued
From the fire scene first
A relay operation is
Using two or more pumpers to move water over a long distance by operating them in series
The pumper that takes water from a hydrant or static source and pumps it under pressure to the next apparatus in the relay pumping operation is called what?
Water supply pumper (aka source pumper)
Increasing flow during a relay operation may be accomplished by what?
Placing additional pumpers in the system
When relaying long distances, the hose lays between each pumper should be what?
As equal as possible
A relay pumping operation begins with what pumper working from the water source?
Largest capacity pumper
A secured hoseline that is used to handle excess water during a relay operation is called what?
Dump line
The introduction of a large amount of air into the pump may cause what?
All of the above
Large diameter hose (LDH) is how big in diameter?
3.5 to 6 inches
The process of releasing a liquid or gas under pressure, such as releasing air from a regulator or cylinder of a self-contained breathing apparatus is called what?
Bleed
What device serves an important role in the safety of a relay operation?
Pressure governor
Clear communications between each driver/operator and the Water Safety Officer is important for what reason?
Safety for all personnel
Appliances that are intended to enhance firefighter safety and reduce the possibility of damage to the pump are called?
Pressure relief valve
A term used within the Incident Command System for a mobile piece of apparatus that has the primary function of supporting another operation is called what?
Tender
The second most important consideration for a relay is what?
Distance
A factor in some relay operations may include what?
Elevation pressure
Fire department driver/operators commonly participate in relay operations. Which type of apparatus can be used for relay pumping?
Any type equipped with an adequately sized pump
What type of operation uses two or more pumpers to move water over a long distance by operating them in series?
Relay
At what psi are centrifugal pumps rated to pump at their maximum volume capacity at draft?
150 psi
What is the maximum waterflow distance(in feet) per pumper when flowing 250gpm through 2 ½ inch hose and a discharge pressure of 200psi?
1,440
What is the maximum volume percentage a fire department pumper is rated to flow at 250 psi?
50
A relay pumping operation begins with the largest capacity pumper working from where?
The water source
For their own safety and efficient operation of the system, all personnel involved in the relay operation must understand that the overall capacity of the system is determined by the?
Smallest pump and the smallest hose diameter used in the relay
In a relay pumping operation, when should the coordinated closing of a dump line take place?
While opening the discharge supplying the hoseline
Apparatus equipped with pressure governors should be set in which mode when acting as the attack pumper and in which mode while working as a relay pumper?
Pressure mode for attack, and rpm for relay
There are several steps when shutting down a relay operation. Beginning with the attack pumper and coordinating with the other relay pumpers, each driver/operator should 1. decrease the throttle, 2. Open the dump line valve, and then?
Disengane the pump
When drafting from a static source, the draft pumper may need to develop what type of pump discharge pressure in relation to the other pumpers in the relay?
Higher
Attack pumpers equipped with an adjustable intake relief valve should be set between 50 and 75 psi. If an attack line is shut down or the amount of discharge decreases, what happens to the friction in the supply line and the residual pressure respectively?
Decreases, increases
During long relay operations smaller capacity pumps may require what type of residual pressures as the relay opeation stabilizes?
Higher
To maintain safety for all personnel, clear communications between which two people is important when the need for relay pumping has ended?
Driver, water supply officer
Which method consists of deploying portable folding drop tanks at each intake for pumpers?
Open relay
Which pumper takes water from a hydrant or static source and pumps it under pressure to the next apparatus in the relay pumping operation?
Water supply pumper
What kind of valves, that are also equipped with a gate valve, allows the water supply to the pump to be shut off?
Screw-on intake pressure relief valve
For relay pumpers equipped with an adjustable intake relief valve, they should be set to 10 psi above the static pressure of the water system to which it is attached or how many psi above the discharge pressure of the previous pumper in the relay?
10
In a relay operation, it is advisable for drivers to maintain an intake pressure of how much psi as a relay pumper?
20-30
Drivers should not attempt to correct minor fluctuations as long as the intake pressure does not drop below how many psi?
20
The pumper that takes water from a hydrant or static source and pumps it under pressure to the next pumper in the relay operation is called?
water supply pumper
The pumper that should have the largest capacity in a relay operation is the?
water supply pumper
The pumper that can be smaller capacity due to its ability to use acquired energy of previous pumpers in the relay is the?
relay pumper
In a relay pumping operation, the fire attack pumper is?
the pumper supplying attack lines and appliances
If the amount of flow through a relay operation needs to be increased, one option may be to?
increase the pump discharge pressure of the pumpers in the relay
Centrifugal pumped have a maximum rated capacity at what pressure during drafting?
150 psi
Which of the following will allow pumpers to operate at lower pressures and maximum flows within the relay operation?
placing additional pumpers in the system
When placing a relay into operation, the relay pumpers intake pressure should be maintain at?
20 to 30 psi
Which of the following devices serve an important safety role in relay operations due to constant increasing of pressure flow?
pressure governors
When drafting from a static source, which pumper may need to develop a higher pump discharge pressure than the other pumpers in the relay?
Water supply pumper/source pumper
If an apparatus is equipment with a pressure governor, what mode should be used to charge attack lines?
pressure mode
If an apparatus is equipment with a pressure governor, what mode should be used to draft from a static source?
RPM mode
When in a relay operation what pumper should be shit down first to limit damage to pumps?
fire scene
In order to prevent water hammer at any point in the relay system, all valves must be closed?
slowly
When operating in a relay operation the driver operator should not correct minor pump fluctuations as long as the intake pressure does not drop below?
20 psi
Which of the following best describes the type of hose diameter used in local jurisdictions to complete a relay?
a variety of hose diameters
Which of the following will reduce damage to the pump and other water supply components if a water hammer occurs?
pressure relief valves
If an attack line is shut down, or the amount of discharge changes, fiction loss in the supply line decrease and?
residual pressure increases
Late arriving pumpers can tie into the relay operations and boost pressure and volume without interrupting water supply flows by?
inline relay valves
Which of the following on the intake pressure relief valve allows air to bleed off as the incoming supply hose is charged?
Bleeder valve
What is it called when you are using two or more pumpers to move water over a long distance by operating them in series with water being discharged from one pumper, flows through hoses to the inlet of the next pumper?
Relay operation
Also known as a source pumper, which pumper in a relay operation should have the largest pumping capacity?
Water supply pumper
Which pumper in a relay operation is responisble for supplying the attack lines and appliances needed for fire suppression?
Fire attack pumper
What will have a major impact on the design of the relay system?
Amount of water required
Centrifugal pumps are rated to pump their maximum volume capacity at what PSI?
150
When pumpers operate at pressures higher than their maximum volume capacity, what happens to the volume capacity?
It is reduced
At no time should discharge pressures exceed what?
The pressure at which hose or appliances have been service tested
What is the only variable that affectes elevation pressure?
Topography
What two variables dictate the overall capacity of a relay operation?
Smallest pump and the smallest hose
How should the relay pump be waiting for water?
Dump line open and pump out of gear
Apparatus equipped with pressure governors should be set in what mode when acting as the attack pumper?
Pressure mode
Which NFPA would a driver/operator refer to for further information regarding the placement of appliances and relief devices?
1962
How many methods of relay pumping are there?
2
What are the methods of relay pumping?
Open and Closed
What can be placed along the length of supply hose that would permit a later arriving pumper to connect to the relay operation without interrupting the supply?
Inline relay valve
What is one way to increas the amount of flow through a relay operation?
Diameter of the supply hose or the number of hose lines must be increased
What will always increase when the length of the lay increases?
Friction loss
Apparatus equipped with pressure governors should be set in what mode when acting as the relay pumper?
RPM Mode
Which appliances are intended to enhance firefighter safety and reduce the possibility of damage to the pump and other water supply components that may be caused by water hammer when valves are opened too quickly or intake pressure rises dramatically?
Reley relief valves
How much residual pressure should the relay pumpers maintain?
20-30 psi
What must all driver/operators maintain for residual intake pressure?
20psi
What pumper should be at the water source in a relay?
largest pumping capacity
What can happen at any point in a relay if valves are not closed slowly?
water hammer
In a relay operation, what should the adjustable intake relief valve be set at on a relay pumper connected to another pumper?
10 psi above the discharge pressure of the previous pumper in the relay
what should the attack pumpers have their adjustable intake relief valve set between?
50 & 75 psi
What might a smaller capacity pumper require in a long relay operations as the relay starts to stabilize?
higher residual pressures
What an effective communication between pumpers if no other communication is available
firefighters as messengers
Open relay method takes advantage of what for each pumper?
portable folding drop tank
What does open relay method eliminate?
pressure surges and inconsistent supply
What NFPA should be refered for information reguarding placement of relief devices?
1962
What are 2 main types of relay methods?
open and closed relay methods
What pumper is located at the scene in a relay operation?
fire attack pumper
What is the pumper called in a relay operation that receives water from the pumper at the source and increases the pressure for the next pumper?
relay pumper
what is the process of releasing a liquid or gas under pressure called?
Bleed
what is a dump line?
Secured hoseline that is used to handle excess water during a relay operation
What happens to a relay pressure if going up hills?
pressure increases
Why is distance an important consideration in a relay operation?
more friction loss will be encountered
What can happen if you fail to keep a static water supply moving in a relay?
loss of prime
How do you increase the pressure of a relay operation?
increase the pump discharge pressure of the pumpers in the relay
What are 2 important relay pumping considerations?
water requirement and distance from water source to scene
Using two or more pumpers to move water over a long distance while operating them in series is called what?
Relay Pumping
The longer the hose lay, what happens to friction?
There will be more friction loss
If the amount of flow through a relay needs to be increased, what is not a condition that must be met?
More hoseline must be added to move more water
Centrifugal pumps are rated to pump a maximum of what?
150 psi
When pumping at pressures higher than 150 psi, what happens to the volume capability of the pump?
Reduced proportionately
Failure to keep water moving through the pump when using a static water supply may result in what?
Loss of prime or the pumper overheating
What is the hoseline that is used to handle excess water during a relay operation?
Dump Line
As a relay pumper, it is advisavle to maintain an intake pressure of what?
20-30 psi
What is the process of releasing a liquid under pressure?
Bleed
When acting as the attack pumper in a relay operation, what mode should the pump be in?
Pressure Mode
When working as a relay pumper, what mode should the pump be in?
RPM Mode
When operating in RPM Mode, if the pressure increases beyond a preset range, what will happen?
The pressure governor will reduce the engine RPMs
What operating mode allows the pressure regulator to attempt to maintain a specific pump pressure by adjusting the engine RPMs as needed?
Pressure Mode
For relay pumpers equipped with an adjustable intake relief valve, what should they be set to?
10 psi above the static pressure or the discharge pressure of the previous pumper in the relay
If an attack pumper is equipped with an adjustable intake relief valve, what should it be set to?
50-75 psi
The DPO should not attempt to correct minor fluctuations in intake pressure unless what happens?
The intake pressure drops below 20 psi
When a relay needs to be shut down, where should it be shut down first?
At the fire scene
During relay pumping, this may be employed to provide an alternate water supply system.
Open Relay Pumping
What is the appliance intended to enhance firefighter safety and reduce the possibility of damage to pumps that may be caused by water hammer?
Relay Relief Valves
DPOs must remember that when operating from a draft, the bleeder valve must be in what position (if connected to an intake with a manual shutoff)?
Closed
What devices typically feature one LDH inlet and a combination of MDH and LDH discharges?
Discharge monitors
What allows a pumper to connect to the valve to boost pressure in the hose?
Inline relay valve
Which of the following is equipped with a gate valve to allow the water supply to the pump to be shut off?
Screw-on intake pressure relief valve
What information does NFPA1962 provide?
Placement of relief devices
What does generally happen when medium diameter hose is used?
Multiple hoselines are laid
Which method consists of deploying portable folding drop tanks at each intake?
Open relay
What must the driver do in order to avoid turbulence in the folding tanks?
Place hard sleeve and supply hoses opposite to each other
When the need for relay pumping has ended, where should the operation be discontinued from first?
Fire scene
The relay shut down procedure has 3 steps, what is the second step?
Open dump line valve
What psi should the adjustable intake relief valve be set at in attack pumpers?
Between 50 and 75
Intake relief valves in relay pumpers should be set at?
10 psi
Which mode should an apparatus with pressure governor be set at while working as a relay pumper?
RPM
Which device serves an important role in safety of a relay operation?
Pressure governor
What is the advisable intake pressure that a driver should mantain as a relay pumper?
20 to 30 psi
Process of releasing a liquid or gas under pressure?
Bleed
What is the secured hoseline used to handle excess water in a relay called?
Dump line
What determines the overall capacity of the relay system?
Smallest pump and smallest diameter of hose
What is the costumary formula do determine the amount of pumpers needed for a relay?
P=R/D+1
How can flow be increased during a relay operation?
Adding pumpers
What is a centrifugal pump rated maximum volume capacity at draft?
150psi
Using two or more pumpers to move water over a long distance by operating them in a series is known as?
Relay operation
The pumper that takes water from a hydrant or static source and pumps it under pressure to the next apparatus in the relay pumping operation is known as the what?
Water supply pumper
The pumper(s) connected within the relay that receive water from the source pumper and raise the pressure while supplying the next apparatus is known as what?
Relay pumper
The pumping apparatus located at the fire scene that recieves water from the relay and is responsible for for supplying attack lines is known as what?
Attack pumper
What is the minimum size for a supply line to be considered “LDH”?
3½”
Which of the following is NOT a factor that directly affects friction loss?
Size of the discharge being used
What is the maximum volume capacity that a centrifugal pump is rated to?
150 PSI
When pumping at pressures higher than 150 PSI, the volume capability of the pump does what?
Reduced proportionally
What is the best way to increase the flow of water during a relay operation?
Place additional pumpers within the relay
Pumpers are rated to flow 50% of their maximum volume at what PSI at draft?
100 PSI
How is the need for relay pumping is determined?
By the amount of water required at an incident and the distance to the water source
Where should the engine with the largest pumping capacity be placed in a relay operation?
At the water source
The overall capacity of a relay operation is determined by what factor?
The smallest pump and diameter of hose in use in the relay
What is the first thing a source pumper should do once the water supply has been established from draft before supplying the relay?
Open a discharge to keep the water moving through the pump
How should the relay pumper be ready to receive water from the source pumper?
With a discharge open and the pump out of gear
A secured hoseline that is used to handle excess water during a relay operation is known as what?
Dump line
During a relay operation, a driver/operator should maintain an intake pressure of what PSI in the relay?
20-30 PSI
The process of releasing a liquid or gas under pressure is known as?
Bleeding
How should apparatus with pressure governors be set in a relay operation?
The attack engine in pressure mode, the rest of the engines in the relay in RPM mode
A pumper in a relay operation equiped with an adjustable intake relief valve should set the relief valve to what pressure?
10 PSI above the static pressure of the incoming water source
Driver/operators must ensure that all pumpers maintain a residual intake pressure of what?
20 psi
Where should pressure decreases begin in a relay?
Attack Pumper
What NFPA standard should drivers refer to regarding placement of relief devices?
1962
What type of relay method consists of deploying portable folding drop tanks at each pumper?
Open
In order to avoid turbulance in a portable folding drop tank, where should the hard sleeve and supply hoses be placed?
Opposite ends
Once the need for a relay has ended, where should the operation be discontinued from?
Fire Scene
Attack pumpers that have adjustable intake relief valves, should have the intake relief valve set between what psi?
50-75 psi
Relay pumpers equipped with adjustable intake relief valves, what psi should they be set above the static pressure of the water supply system?
10 psi
A relay pumper equipped with a pressure governor shoul be in what mode while acting in a relay?
RPM
Relay pumpers should maintain an intake pressure of at least what?
20 psi
When can the pump on a relay pumper be engaged?
Once a steady flow of water is issued from the dump line
How should a relay pumper be waiting for water?
Discharge open and pump out of gear
The overall capacity of the relay system is determined by what?
Smallest pump and smallest diameter of hose
Where should the ;argest capacity pumper be in a relay?
Source
What two factors determine the need for relay pumping?
Amount of water and distance to incident
Fire department pumpers are rated to flow there maximum volume at what psi?
150 psi
Fire department pumpers are able to flow 70 percent of their maximum volume at what psi?
200
At 250 psi, fire department pumpers are capable of flowing what percentage of their maximum volume?
50%
Centrifugal pumps are rated to pump their maximum capacity at what psi when at draft?
150 psi
In order to be effective, relay operations require what?
All of the above
When using two or more pumpers to move water over a long distance by operating them in a series is known as what?
Relay pumping
Any type of apparatus equipped with what can be used in relay pumping?
Adequately sized pump
A pumper that takes water from a hydrant or static source and pumps it under pressure to the next apparatus in the relay pumping operation is called what?
Water supply pumper
A pumper connected within the relay that receive water from the source pumper, raises the pressure and then supplies water to the next apparatus is called what?
Relay pumper
What is the term used within the Incident Command System for a mobile piece of apparatus that has the primary function of supporting another operation called?
Tender
Large Diameter Hose (LDH) is what size in diameter?
3.5 - 6 inches
What can assist relay pumping operations that require large lengths of supply hose?
Hose tender
The need for relay pumping is determined by what?
Amount of water required at an incident and distance between the incident scene and the water source
The second important consideration for a relay is what?
The distance
Centrifugal pumps are rated to pump at their maximum volume capacity at what pressure?
150 PSI
Centrifugal pumps are rated to pump at 75% their maximum volume capacity at what pressure?
200 PSI
Centrifugal pumps are rated to pump at 50% their maximum volume capacity at what pressure?
250 PSI
When relaying long distances, the hose lays between each pumper should be what?
Equal
The process of allowing air to escape from a hoseline before or during operations is called what?
Bleed
When should a source pumper open a discharge or allow water to discharge through a dump line until the first relay pumper is ready for water?
Once water supply has been established
A secured hoseline that is used to handle excess water during a relay operation is called what?
Dump line
Relay pumpers equipped with an adjustable intake relief valve should be set to what PSI above the static pressure of the water system to which it is attached
10 PSI
Attack pumpers equipped with an adjustable intake relief valve should be set where to establish a stable operating condition?
50 - 75 PSI
The driver/operator of the attack pumper should not attempt to correct minor fluctuations as long as the intake pressure does not drop below what?
20 PSI
When the need for relay pumping has ended, the operation should be discontinued from where?
Fire Scene
Which operation is when water discharged from one pumper flows through hoses to the inlet of the next pumper?
Relay operation
What apparatus should have the largest pumping capacity?
Water supply pumpers
Which apparatus may be of smaller capacity due to its ability to use the aquired energy of previous pumpers ?
Relay pumper
This apparatus is responsible for supplying the attack lines and appliances required for fire suppression:
Fire attack pumper
What type of apparatus is used to assist in relay opertions when some fire departments have to make long hose lays?
Hose tenders
What is commonly divided into attack and supply line categories?
LDH
This is determined by the amount of water needed and the distance between the incident and water source?
Relay pumping
What is the second important cosideration of a relay?
Distance
If the water supply must be pumped uphill, the pressure loss on the lay is greater than what?
Simple friction loss
What could be a factor that will shorten the length of hose each pumper must supply and allow to operate at lower pressures?
Placing additional pumpers in the system
What is the elevation pressure affected by?
Topography
P=R+1/D is the formula to determine what?
Relay distance
How should the hose lays between each pumper be when relaying long distances?
As equalized as possible
All of the following are general guideline for safe and efficient relay operation except:
Positioning
When drafting from a static source, this pumper may need to develop a higher pump discharge than the others:
Largest capacity pumper
Choose the most accurate about, the source pumper does not have the residual pressure at the intake that;
Relay pumpers receive that helps prevent cavitation
What is determined by the smallest pump and the smallest diameter of hose in a relay?
Overall capacity of the system
What is the mximum advisable intake pressure a driver can maintain as a relay pumper?
30 psi
What will cause reduced residual pressure and the intake relief valve could close?
Increase in demand by attack pumper
This device will allow later arriving pumpers to boost pressure and volume without interrupting water supply?
Inline relay valve
Which pumping operation is described as using two or more pumpers to move water over a long distance?
Relay operation
In relay pumping operations, which pumper takes water from the hydrant or static water source and pumps it under pressure to the next apparatus in the relay?
Water supply pumper
In relay pumping operations, which pumper is connected within the relay that receive water from the source pumper, raises the pressure, and then supplies water to the next apparatus?
Relay pumper
Which pumping position in relay operations should the apparatus with the largest pumping capacity take?
Water supply pumper
In relay pumping operations, what is the apparatus that is located at the fire scene that recieves water from the relay and is responsible for suppling the attack lines and appliances for fire suppression?
Fire attack pumper
What can be utilized to assist in relay pumping operations where long hose lays may have to be made?
Hose tenders
Centrifugal pumps are rated to pump at their maximum volume capacity at what psi at draft?
150 psi
What is the result of pumping at pressures higher than 150 psi?
The volume capability of the pump is reduced proportionately
Fire department pumpers are rated to flow what percent of their maximum volume at 200 psi?
70
Fire department pumpers are rated to flow what percent of their maximum volume at 250 psi?
50
It is advisable for driver/operators to maintain an intake pressure of what, as a relay pumper?
20-30 psi
When relaying long distances, the hose lays between each pumper should be what?
As equalized as possible
The overall capacity of the relay system is determined by what?
The smallest pump and the smallest diameter hose
Attack pumpers equipped with an adjustable intake relief valve should be set between what psi to establish a stable operating condition?
50-75 psi
For relay pumpers equipped with an adjustable intake relief valve, they should be set to what psi above the static pressure of the water system to which it is attached?
10 psi
Which relay method consists of deploying portable folding drop tanks at each intake for pumpers in the relay operation?
Open relay method
Which relay method consists of using multiple LDH in between relay pumpers?
Closed relay method
The need for a relay operation is based on what two factors?
Amount of water required and distance between the scene and water source
Relay operations should be shut down from where?
The fire scene
What appliance can reduce the possibility of damage to the pump and other water supply components that may be caused by water hamer when valves are operated too quickly or intake pressures rise dramatically?
Pressure relief valves
The pumper that receives water from the source or another relay pumper, raises the pressure, and supplies water to the next apparatus is called?
relay pumper
The need for a relay operation is based on which two factors?
amount of water required and distance between the scene and water source
which of the following will allow pumpers to operate at lower pressures and maximum flows within the relay operation?
greater than simple friction loss
When relaying long distances, if pumpers carrying different diameters of supply hose are to be used in the operation, distance?
must be adjusted to compensate for each size of hose
What two factors determine the overall capacity of a relay system?
smallest pump and the smallest diameter of hose hosed used in the relay
Centrifugal pumped have a maximum rated capacity of what pressure during drafting?
250 psi
Once the relay is in operation the driver/operator of the attack pumper should not attempt to correct minor fluctuations as long as the intake pressure does not drop below?
20 psi
Why might the open relay method be employed in a relay operations?
provide an alternate water supply system
Which of the following is a characteristic of an open relay?
deploys portable folding drop tanks at each intake for pumpers in the relay operation
What type of relay requires no adapters or other appliances to connect intake hoses in the system?
open relay
If an apparatus is equipment with a pressure governor, what mode should be used to charge attack lines?
pressure mode
If an apparatus is equipment with a pressure governor, what mode should be used to draft from a static source?
RPM mode
When in a relay operation what pumper should be shit down first to limit damage to pumps?
fire scene
In order to prevent water hammer at any point in the relay system, all valves must be closed?
slowly
When operating in a relay operation the driver operator should not correct minor pump fluctuations as long as the intake pressure does not drop below?
20 psi
Which of the following best describes the type of hose diameter used in local jurisdictions to complete a relay?
a variety of hose diameters
Which of the following will reduce damage to the pump and other water supply components if a water hammer occurs?
pressure relief valves
If an attack line is shut down, or the amount of discharge changes, fiction loss in the supply line decrease and?
residual pressure increases
Late arriving pumpers can tie into the relay operations and boost pressure and volume without interrupting water supply flows by?
inline relay valves
Which of the following on the intake pressure relief valve allows air to bleed of as the incoming supply hose is charged?
Bleeder valve
What pumper takes water from a hydrant or static source and pumps it to the next appartatus in a relay?
water supply pumper
What pumper should have the largest pumping capacity?
water supply pumper
what pumper is located at the fire scene and supplies the attack lines?
attack pumper
what pumper receives water from a pumper and ups the pressure to send to the next apparatus?
relay pumper
What is considered Large diameter hose?
3.5 -6 inch hose
What happens with a longer hose lay?
more friction loss
what must happen for pumper to overcome great friction loss?
add more pumpers
what pressure are cetrifugal pumps rated to pump the maxium volume capacity at?
150 psi
what happens to the rated capactiy of a centrifugal pump if the pressure is over 150 psi?
volume of pump is reduced proportionately
At what percentage does a centrifugal pump flow at 200psi?
70%
At what percentage does a centrifugal pump flow at 250psi?
50%
At what percentage does a centrifugal pump flow at 150 psi?
100%
what is the process of releasing liquid or gas under pressure?
bleed
What is a secured hoseline that is used to handle excess water?
dump line
Where the largest capacity pumper in a relay operation?
at the source
which relay uses portable folding tanks at each pumper?
open relay
where do you shut a relay down from?
the fire scene first
What can help the relay reach the flow requirements form late arriving pumpers?
inline relay valve
When may a relay operation be needed?
wherever a water supply is too far
what relay method needs no adapters or other appliances?
open relay
What instances can force drivers to use relay pumping operations?
Remote water source
What is considered using two or more pumpers to move water over a long distance by operating them in series?
Relay Operation
Which pumper takes the water from the water source and pumps it under pressure to the next apparatus in the relay?
Water supply pumper
What type of pumper should be avoided to be used as the water supply pumper and why?
Smaller pumper due to limitations in fire flow
Which pumper is a pumper connected within the relay that receives water from the source pumper or another pumper of it’s kind, raises the pressure and then supplies water to the next apparatus?
Relay pumper
Which pumper is the apparatus located at the fire scene?
Fire attack pumper
What is the range of diameter for LDH considered to be?
3.5”-6”
What determines the need for relay operations?
The amount of water required at an incident and the distance between the scene and the water source
What happens to the friction loss as the distance the water travels increases?
Increases
If the amount of water needs to be increased, what must occur?
The diameter of the hose must be increased, or the PDP must be increased or more pumpers need to be added to the relay
What are centrifugal pumps rated to pump at for max GPMs?
150psi
What is the maximum waterflow distance for a pumper that is flowing 1000gpms with one 4” hose?
825ft
What percent of max GPMs does a pumper deliver if pumped at 250 psi?
50%
What is the formula to determine the number of pumpers needed at a relay operation?
P= R/D +1
What should happen to the distances of the hose lays between pumpers during long relay operations?
They should be as equalized as possible
Where should the largest capacity pumper be placed during relay operations?
At the water source
Once the water supply has been established, what should the source pumper do until the first relay pumper is ready for water?
Open a discharge or allow water to discharge through a dump line
What is a secured hoseline that is used to handle excess water during a relay operation?
Dump line
What should the driver/operator do prior to opening an intake valve when receiving water?
Bleed any air from the line
Where should the relay operation be shut down from first when the need for relay is over?
From the fire scene
Using two or more pumpers to move water over a long distance by operating them in a series
Relay operation
Pumper that takes water from a hydrant or static source and pumps it under pressure to the next apparatus in the relay pumping operation.
Water supply pumper
Pumper or pumpers connected within the relay that receive water from the source pumper or another relay pumper, raises the pressure, and then supplies water to the next apparatus.
Relay pumper
Pumping apparatus located at the fire scene that receives water from the relay and is responsible for supplying the attack lines and appliances required for fire suppression.
Fire attack pumper
is determined by the amount of water required at an incident and the distance between the incident scene and the water source.
the need for relay pumping
Centrifugal pumps are rated to pump at their maximum volume capacity at how many psi at draft?
150
fire department pumpers are rated to flow 70 percent of their maximum at how many psi at draft
200
fire department pumpers are rated to flow 50 percent of their maximum at how psi at draft.
250
(Customary and Metric) — Relay Distance
P = R/D+ 1
P
Total number of pumpers needed
R
Relay distance
D
Distance from
overall capacity of the system is determined by what used in the relay?
smallest pump and the smallest diameter of hose
Failure to keep water moving through the pump when using a static water supply may result in loss of prime or overheating the pump, either of which
would delay the operation
Secured hoseline that is used to handle excess water during a relay operation
Dump line
It is advisable for driver/operators to maintain an intake pressure of what psi as a relay pumper?
20 to 30
As water begins to reach each pumper, the driver/operator should do what before opening the intake valve?
bleed any air from the line
Once the relay operation is flowing water at the desired pressure, the driver/operator of the attack pumper should set the pressure governor
at an appropriate level
For relay pumpers equipped with an adjustable intake relief valve, they should be set to what psi above the static pressure of the water system to which it is attached?
10
Using 2 or more pumpers to move water over a long distance by operating them in series is called?
Relay Operation
A term used in ICS for a mobile piece of apparatus that’s primary function is supporting another operation is called?
Tender
An apparatus that takes water from a hydrant or static water source and pumps it under pressure is called?
Water Supply Pumper
A pumper(s)connected with in a relay that receives water, raises the pressure and supply’s another pumper is called?
Relay Pumper
The pumper that supply’s the attach lines is called?
Attack Pumper
What inch range is considered large diameter hose?
3 1/2” to 6”
What will have a major impact on the design of a relay system?
Amount of water required
At what PSI do fire department pumpers flow there maximum volume?
150
What are the three parts to the relay distance formula?
Pumpers, distance, Distance from table12.1or 12.2
A safe and efficient relay operation depends on 3 things, what are they?
Coordination, communication, planning
What pumper should be the drafting pumper in a relay?
Largest capacity
The overall capacity of a relay system is determined by?
Smallest pump capacity/ hose diameter
When a pump is at draft, what must it do to keep a draft?
Move water
A second hose line that is used to handle excess water during a relay is?
Dump line
What is recommended to maintain as the minimum intake pressure in a relay?
20-30 PSI
What needs to be done before an intake valve is opened in a relay?
Bleed incoming line
What pumper should be in RPM in a relay
Relay pumper
What pumper should be in the Pressure mode in a relay?
Attach pumper
What pumper shuts down first in a relay?
Attack Pumper
A relay method where each pumper drafts from a pit is called?
Open Relay Method
