Water Relay Flashcards
Water relay involves spacing a number of ____ at regular_____ along a route between the water source and the point where the _____ is needed.
Water relay involves spacing a number of pumps at regular intervals along a route between the water source and the point where the water is needed.
A water relay is used when the water supply is ____ from the ______ and required _______ the water from that location to the fireground.
A water relay is used when the water supply is distant from the fireground and required moving the water from that location to the fireground.
• The _____ of the tanker, filling ____, _____ time and fireground requirements (L/m) will dictate the ________ of tankers required to “_______” the water.
• The capacity of the tanker, filling time, travel time and fireground requirements (L/m) will dictate the numbers of tankers required to “shuttle” the water.
- ____ circuit water relay is when the first pump takes water from a source and ____ it through hose lines into some form of ___ such as a portable dam, ____ tank or another tanker.
- The second pump then ____ water from that reservoir through it’s suction hose and delivers it to the next ____ or its _____ destination.
- Open circuit water relay is when the first pump takes water from a source and pumps it through hose lines into some form of reservoir such as a portable dam, collar tank or another tanker.
- The second pump then draughts water from that reservoir through it’s suction hose and delivers it to the next reservoir or its final destination.
Open Circuit water relay
• Advantages
– Hose and equipment doesn’t need to be ___ ___ ___
– Filling of _____ can take place when and as required
– ____ trucks can fill a reservoir or alternatively ___ from a reservoir
– General ____ with resources and equipment
– Pumps can be replaced without ____ the water ________
Open Circuit water relay
• Advantages
– Hose and equipment doesn’t need to be left in place
– Filling of reservoirs can take place when and as required
– Multiple trucks can fill a reservoir or alternatively draught from a reservoir
– General flexibility with resources and equipment
– Pumps can be replaced without interrupting the water supply
Open Circuit water relay
• Disadvantages
– Unable to ___ supply ___ from previous pump
– Delivery pressure must be generated at __ ___ of the pump relay
– Need for ____
– Ability to ____ individual reservoirs
– _____ to setup
Open Circuit water relay
• Disadvantages
– Unable to harness supply pressure from previous pump
– Delivery pressure must be generated at each leg of the pump relay
– Need for reservoirs
– Ability to overflow individual reservoirs
– Manpower to setup
Closed circuit water relay
A ____ circuit water relay is when water is pumped at the water source through hose lines connected ____ to the inlet of a second (booster) pump.
The second pump may in turn be _____ to the inlet of a third pump, and so on until water is __________ to the fire ground.
Closed circuit water relay
A closed circuit water relay is when water is pumped at the water source through hose lines connected directly to the inlet of a second (booster) pump.
The second pump may in turn be connected to the inlet of a third pump, and so on until water is delivered to the fire ground.
Closed circuit water relay
• Advantages
– Ability to harness generated pressure from _____ pump(s)
– _____ equipment required
– No need for ____
– ____ flow of water from the base pump to the _________ pump
– Easier to deliver ____ volumes and _______ to the fireground
Closed circuit water relay
• Advantages
– Ability to harness generated pressure from previous pump(s)
– Less equipment required
– No need for reservoirs
– Continuous flow of water from the base pump to the fireground pump
– Easier to deliver large volumes and pressures to the fireground
Closed circuit water relay
• Disadvantages
– Requires ____ standard of pump operation
– ____ between pumps is vital
– Flow of water _____ if pump replaced or if hose burst
– Can take _____ to setup and shutdown
Closed circuit water relay
• Disadvantages
– Requires higher standard of pump operation
– Communication between pumps is vital
– Flow of water interrupted if pump replaced or if hose burst
– Can take time to setup and shutdown
Distance between pumps depends on:
- The quantity of water required at fire ground.
- The diameter of hose used or available.
- The number of hoselines between pumps.
- The topography of the relay route.
- The capacity of each pump.
Calculating distance between pumps.
- Best performance of each pump is it’s ___ point - ____.
- Allow for final delivery pressure of ___ kpa at each pump and ensure residual inlet pressure of ____ kpa.
- Therefore we have ___ kpa available to overcome the _____ loss and loss due to ___.
Calculating distance between pumps.
- Best performance of each pump is it’s duty point - 700kpa.
- Allow for final delivery pressure of 700 kpa at each pump and ensure residual inlet pressure of 100 kpa.
- Therefore we have 600 kpa available to overcome the friction loss and loss due to head.
Formula to calculate number of hoses required in pump relay
Number of hoses = 600kpa +/- Static head
Friction loss per length
Static head is also known as:
net head
Forming The Relay
- 1st appliance to attack fire from tank supply. Becomes _____ pump.
- _____ pump at water supply
- Calculate ____ between pumps
- Hose laid and pumps _____
- Each booster pump releases ____ from system through ___ delivery as the water advances
- Pumps ____ only when water is in ____ casing
- Base pump runs at ____
- Booster pumps, when receive water, close bleed delivery and pump at ______
- ____ pump increases to ____
- Each successive booster pumps increase to _____ with ______ in reserve on the inlet gauge.
Forming The Relay
- 1st appliance to attack fire from tank supply. Becomes fireground pump.
- Largest pump at water supply
- Calculate distance between pumps
- Hose laid and pumps located
- Each booster pump releases air from system through unused delivery as the water advances
- Pumps engage only when water is in pump casing
- Base pump runs at 500kpa
- Booster pumps, when receive water, close bleed delivery and pump at 500kpa
- Base pump increases to 700kpa
- Each successive booster pumps increase to 700kpa with 100kpa in reserve on the inlet gauge.
Shutting Down The Relay
- Fireground pump ___________ to all pumps in relay of _________ shutdown
- All pumps ________ imminent shutdown
- ______ pump reduces delivery pressure to ____ kPa
- Next booster pump reduces pressure to ____ kPa
- _____ pump reduces pressure to _____ kPa
- _______ pump returns pump to ____ and then ________ pump
Next booster pump returns pump to _____ and ______ pump
Base pump ____ _____
As all pumps keep ________ opened, no water _________ is trapped between pumps and is allowed to ______.
Shutting Down The Relay
- Fireground pump communicates to all pumps in relay of imminent shutdown
- All pumps acknowledge imminent shutdown
- Fireground pump reduces delivery pressure to 500 kPa
- Next booster pump reduces pressure to 500 kPa
- Base pump reduces pressure to 500 kPa
- Fireground pump returns pump to idle and then disengages pump
Next booster pump returns pump to idle and disengages pump
Base pump shuts down
As all pumps keep deliveries opened, no water pressure is trapped between pumps and is allowed to drain.
