Pumping Flashcards
What is a pump?
Machine, driven by external power, to give energy to fluid
What are the two types of pump used on front line appliances?
Centrifugal pump
Positive displacement pump
What features does a centrifugal pump have?
Main LFB pump used on appliances, external power is road engine, cannot pump gas or air
What features does a positive displacement pump have?
Work by moving a piston through a cylinder, bicycle pump is an example, can pump gas, examples are stirrup pump used on chimney fires and priming device found on light portable pump, hand operated
What parts does a centrifugal pump have?
Impeller
Volute
What does the impeller do?
Imparts kinetic energy to the fluid, rotating part of centrifugal pump, central inlet is called ‘eye of the pump’
What does the Volute part of the centrifugal pump do?
Converts kinetic energy to pressure energy
What is the PTO?
‘Power Take Off’ - in Fire appliance, impeller is fixed to drive shaft driven by road engine, power is diverted from road wheels to seperate drive shaft by engaging the PTO
What is a UMP?
‘Universal Multi Pressure Pump’ - low pressure impeller and peripheral impeller is fixed to same drive shaft, housed within same casing
What is the major pump used in LFB Mercedes appliance and what is its features?
‘Godiva World Series multi pressure pump’ - it supplies high volume of water at low pressure, low volumes at high pressure, both low and high simultaneously
What pressures and flow rates do the hose reels operate at/produce when being supplied from a peripheral impeller?
35-40 bar
115-150 lpm
How much in litres does the appliance tank contain when full?
1400 Litres, each light contains a quarter of tank
What are the pump gauges in the appliance?
Water tank contents indicator Rev counter Compound gauge High pressure gauge Low pressure gauge
What is low pressure gauge reading?
Used to make sure pump is delivering correct pressure to the branch operators
What could a sudden increase in a low pressure gauge indicate?
1) Branches being shut down
2) kinks in the delivery hose
3) Vehicles or debris on delivery hose
What could sudden decrease in low pressure gauge reading indicate?
1) Branches being opened
2) burst delivery hose
3) appliance tank empty
What is the Engine speed joystick?
Increases or decreases speed of pump giving more or less pressure to the water at delivery outlet of pump
What is PTO switch?
Engages PTO?
What is function (master) button?
Must be depressed at same time as pump control switches for them to operate
What must happen in order for the appliance pump to work?
1) Engine must be running and incident/speed switch engaged in cab
2) once pumping operator must continually monitor and adjust controls to maintain desired pressure & flow of water to branch
What do you do when operating the pump?
1) Air dump switch
2) press and hold function button and PTO switch
3) check lights on PTO switch illuminates
What do you do when hose reels are no longer in use? And why?
Switch to low pressure ‘LP’, significantly reduces noise, fuel consumption and exhaust emission, prevents pump from overheating
What is provided to avoid overheating?
Automatic thermal Relief valve, disengage PTO if pump is not required immediately
What do you do if a delivery is left open for cooling?
A length of 70mm hose should be attached to direct water to a suitable drainage point
What can the pump operator do if the supply is overrun?
PO can calculate the number of branches to be closed or flow setting to be reduced in order to restore balanced flow
What is a flow metre?
Registers flow rate of water going into the tank in LPM, allows pump operator to assess quality of hydrant supply and monitor systems working correctly
What is Auto fill valve?
Water flowing from inlet collecting head to appliance tank passes through AFV, it makes sure tank remains above 3/4 full without overflowing
What do you do if length of soft suction hydrant bursts?
Inlet valve controlling its flow should be closed until hydrant can be shut down and hose replaced, prevents water flowing down burst length and spilling everywhere
What should supplies alway be?
Twinned from the same source (appliance or hydrant)
What is overrunning the supply?
Where pump is delivering more water than it is receiving through the augmented supply
How do you prevent the occurrence of overrunning?
Pump operator should observe flow metre when auto valve is fully open, reading given will be total quantity available for use without overrunning supply.
How is overrunning recognised?
Falling level of water tank contents indicator
What steps to be taken after overrunning is recognised?
1) increase the supply
2) regulate amount of water delivered by reducing no. of jets, branch flow settings, appliance engine revs
Pump operators should?
1) site the appliance appropriately
2) establish branch settings and supply flow
3) Monitor gauges, flow meter and water tank contents indicator to prevent overrunning, ensure correct pressure delivery to branches and make sure pump is performing correctly
4) overview of incident
5) observe hazard area
6) establish radio communication
Why do you keep hand on top of branch?
Stop gloves from getting wet
Prevent kick back from force of water
What are the checks done on the appliance?
Make sure equipment is stowed correctly
Make sure replenished
Make sure equipment is in operational use
What is the theoretical maximum lift when lifting from open water?
10m
