Flashcards in Chapter 12 - Relay Pumping Operations Deck (49)
- Using two or more pumpers to move water over a long distance by operating them in series; water discharged from one pumper flows through hoses to the inlet of the next pumper and so on.
Relay Operation ( also known as Relay Pumping )
- Pumper that takes water from a hydrant or static source and pumps under pressure to the next apparatus in the relay pumping operation.
Water supply pumper
Water supply pumpers should be the apparatus with the largest ?
Some jurisdictions refer to water supply pumpers as ?
- 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.
- 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
Some fire departments, especially those that have occasion to make many long hose lays, employ hose _________ to assist in relay pumping operations.
- Term used within the Incident Command System for a mobile piece of apparatus that has the primary function of supporting another operation.
ex. Water tender or fuel tender
It is possible for a hose tender to carry a mile or more of ?
large diameter hose (LDH)
- Relay supply hose of 3 1/2 to 6 inches in diameter; used to move large volumes of water quickly with a minimum number of pumpers and personnel.
Large Diameter Hose (LDH)
Basically the need for relay pumping is determined by the amount of ________ required at an incident and the __________ between the incident scene and the water source.
water / distance
If the amount of flow through a relay operation needs to be increased, depending on the size of the supply hose and fire flow requirements, at least one of three conditions must be met:
* The ___________ of the supply hose or the _________ of hoselines must be increased.
* The pump __________ __________ of the pumpers involved in the relay must be increased.
* More __________ must be added to the relay to overcome friction loss or elevation.
* diameter / number
* discharge pressure
True or False:
If pumpers in the relay operation increase their pump discharge pressure, the volume of water through the system will always increase ?
this action will not necessarily increase the volume of water
Centrifugal pumps are rated to pump at their maximum volume capacity at ______ psi at draft. When pumping at pressures higher than _____ psi, the volume capability of the pump is reduced proportionately.
150 / 150
At no time should discharge pressures exceed the pressure at which hose or appliances have been ?
Elevation pressure is not affected by the amount of water being moved only by the ____________.
Increasing flow during a relay operation may be accomplished by placing ?
additional pumpers in the system
Relay operations may use ______ to supply a low flow rate where the distance between each pumper exceeds the length of supply hose carried on each pumper.
Fire department pumpers are rated to flow their maximum volume at 150 psi, ____ percent of their maximum at 200 psi, and ____ percent of their maximum at 250 psi at draft.
70 / 50
When relaying long distances, the hose lays between each pumper should be as ?
equalized as possible
A relay pumping operation begins with the ________ ________ pumper working from the water source.
The source pumper does not have the __________ pressure at the intake that the relay pumpers receive that aids in preventing cavitation.
For their own safety and the 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 ________ pump and the _________ diameter of hose used in the relay.
smallest / smallest
Once water supply has been established, the source pumper should open a __________ or allow water to discharge through a ______ ______ until the first relay pumper is ready for water.
discharge / dump line
The relay pumper should be waiting for water with a _____ ______ or __________ open and the pump out of ______.
dump line / discharge / gear
When the source and relay pumpers are ready, the __________ supplying the hose line on the source pumper is opened while the valve on the ______ ______ is closed in a coordinated action.
discharge / dump line
- Secured hoseline that is used to handle excess water during a relay operation.
It is advisable for the D/O to maintain an intake pressure of ____ to ____ psi as a relay pumper.
20 to 30 psi
As water begins to reach each pumper, the D/O should _____ any air from the line before opening the intake valve.