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
