Pumping Flashcards
5 Laws of friction loss
Friction loss increases directly with the length of the hose
Friction loss increases directly with the decrease in diameter
Friction loss increases directly as the square of the flow rate. Double flow equals 4 times pressure loss
Friction loss increases with the roughness of the interior of the hose.
Friction loss, for all practical purposes, is independent of pressure.
Friction loss DRISL
D Diameter of hose
R Roughness of hose
I Independent of pressure
S Square of the flow rate
L Length of hose
1m head equals
10 KpA
Loss of friction in each hose @ 500l/m?
38mm 220kpa
50mm 75kpa
65mm 25kpa
90mm 5kpa
The water supply for firefighting may come from
A static/open source such as a dam, creek or swimming pool.
A pressurised source such as a hydrant, the pump of another firefighting appliance or
an elevated tank.
What is a pump
A pump is a mechanical device that pushes or moves fluid or air from one place to another
2 main parts of pump
Volute - part of the pump casing itself and is shaped like the shell of a snail
Impeller - circular disc (the back shroud) with curved vane
Advantages of Centrufugal pump
Steady flow
Operates at variable pressures
Simple construction and operation
Easily maintained and less likely to be damaged
Pumps dirty or gritty water with minimal damage to pump
Small and compact
Flow can be interrupted without stopping engine
Can be connected to an internal combustion engine by direct drive
Disadvantages of Centrifugal
A centrifugal pump cannot displace air and needs to be primed if no water is present in the pump casing
An additional pump is required to do this, one that is able to displace the air and introduce water into the main pump casing
Requires different design features, rotation speeds and engine power combinations compatible with pumping water efficiently
Types of centrifugal pumps
SIngle stage
Multi stage - Series
- Parralel
Duty point - Flow from pumps
Heavy Pump
4000l/min @1000kpa 3m lift
MK5
3800l/min @1000kpa 3m lift
Compound gauge - green
The compound gauge shows atmospheric pressure.
Measures pressure on the inlet side of the pump. Can be positive when pressurised water is entering the pump (such as from a
reticulated supply)
Can be negative (red) when air is being displaced by the primer (such as when using tank supply or drafting from a static supply) or water supply is being overrun (attempting to deliver more water than is available from the pressurised supply)
Low pressure
Main pump
Orange MK5
Blue HEAVY
Shows the water pressure in the main pump or low pressure pump casing in kPa.
Gauge is labelled ‘low pressure’ as it is the outlet of the first impeller, which is a lower pressure than the outlet of the second impeller which is connected in series
Maximum operating pressure of the main pump is 1400kpa
High pressure - RED
Always red and linked to the hose reels
Maximum is 4000kpa
Mk5 2000kpa
Heavy 3000kpa
Portable pumps
Portable pumps are independent pumping units that can be carried by one or several firefighters. They are usually centrifugal pumps powered by a small diesel or two or four stroke petrol engine.
Mid mounted appliance pump
Located behind crew cabin and fixed to vehicle chassis.
The pump is driven by the vehicle’s engine through a power take-off which draws engine power through a
supplementary transmission and shaft to the pump.
PTO
The PTO is attached directly to the transmission. When activated, it directs power away from the vehicle driveline to the pump shaft.
Depending on the location of the PTO in relation to the transmission, some appliances will need to be placed in Drive (D) after PTO engagement to start the pump, whilst others can remain in Neutral (N) when the PTO is engaged. Since the PTO directs engine power to
the pump and away from the wheels, the appliance cannot be moved once the PTO is selected
Safety margin on compound
100kpa
HEAVY pumper details
Godiva WTB 4010 rear mounted Multi-Stage Pump
Water Tank Capacity 2000 litres.
Foam Capacity ‘B’ Class 300 litre
Low Pressure 4000 L/min at 1000 kPa
High Pressure 750 L/min at 5500 kPa – periphal pump
Maximum Flow Capacity 6200 L/min
No pump and roll
HEAVY pumper engagement
Stop the vehicle
Apply the park brake
Select N (neutral) on the transmission. The instrument cluster will display N-N.
EXT switch
Engage PTO (centre console) by rotating the switch clockwise.
Select Drive (D) on the Transmission The green OKAY TO PUMP light illuminates and the instrument cluster will display 4-4.
MK5 Pump specs - Pump KPA, Tank volume, LPM
Height: 3.10 metres.
Width: 3.00 metres over mirrors
Length: 8.10 metres.
Weight: 12.80 tonnes (Gross Vehicle Mass 16.00 tonnes).
Fuel: Diesel (200 litres capacity located on the offside).
Main Pump: Darley KSPAH 1000 mid-mounted single stage centrifugal pump with a 2nd stage high pressure.
Pump capacity: 3800 L/min at 1000 kPa.
Primer: Two (2) positive displacement vane type pumps.
Foam System Capacity 3% Foam 3800 L/min 6% Foam 2650 L/min
Water Tank Capacity: 1300 litres.
Foam Tanks Capacities: ‘A’ Class 25 litres. ‘B’ Class 300 litres.
Monitor Water 3800 L/min
MK5 pumper engagement
- Apply the park brake and place transmission in neutral.
- Switch on the pump master electrical switch (pause).
- Switch on the 2nd stage pump switch (pause).
- Switch on the main pump switch.
- Listen to hear that the pumps have engaged.
- Exit the appliance and check that both the main pump and 2nd stage pump lights are illuminated on the primary pump panel.
To disengage the main pump and second (2nd) stage:
1. Switch off the main pump – Pause and wait for light to go out.
2. Disengage the 2nd stage pump – Pause and wait for light to go out.
3. Switch off the pump master electrical switch.
4. Listen to hear whether pumps have disengaged
MK5 Pumper tanker engagement
- Apply the park brake and place the transmission in neutral.
- Switch on the pump master electrical switch – Pause.
- Switch on the 2nd stage pump switch – Pause.
- Switch on the main pump switch – Pause.
- Place the transmission in drive.
- Listen to hear the pumps engage.
- Exit the appliance and check that both the main pump and 2nd stage pump lights are illuminated on the primary pump panel.
To disengage the main pump and second stage:
1. Place the transmission in neutral.
2. Switch off the main pump – pause and wait for the light to go out.
3. Disengage the 2nd stage pump – pause and wait for the light to go out.
4. Switch off the pump master electrical switch
MK5 pump protection
Suction Relief Valve
Needs to be set to protect the pump from excess pressure entering
the pump. Set by the operator of the pump receiving water supply via relay pumping.
Discharge Pressure Relief Valve
Should be set when operating a pump in any mode, but is
particularly important when operating in manual mode (hand throttle). It is also used as a failsafe to ensure pressures greater than 1400 kPa are not delivered from the pump.
Emergency Stop Button
Activation of the emergency stop button will automatically reduce the engine speed/pump revolutions to idle speed.
Pump Overheat
In the event the pump overheating, a thermal relief will open
and discharge water to ground until pump has cooled. A
pump overheat warning light will activate.
Low Water Level Warning
Water level sensors are used to detect the water level at ¼ and ¾ of the tank’s capacity (to provide activation/deactivation signal).
When the water level falls below ¼ of the tank’s capacity, visual and audible warnings will be activated.
Impeller Cooling
This is the provision of constant bleed lines from the main pump discharge and 2nd stage discharge, to bleed a small quantity of water (approximately 18 L/min) to the water tank.
When the water tank is full, water will pass to waste
HEAVY pump protection
Pressure Relief Valve
Diverts water with excess pressure into the low pressure side of the pump
Thermal Relief Valve
This valve operates when the temperature of the water inside the pump increases to 45-50 degrees Celsius
It diverts the heated water to the ground and allows fresh water to circulate and cool the pump
Recirculation Valve
There is a small cooling line between the low and high pressure stages of the pump
There is a manually operated recirculation line between the pump outlet and water tank. It allows for filling of the water tank when there is a reticulated supply connected, as well as cooling the pump system as required
Cavitation Protection
The governor will automatically drop the engine RPM to idle when there is insufficient water supply entering the pump and there is a risk of cavitation occurring
This action is confirmed with the display of ‘WATER SUPPLY’ on the governor
Automatic Primers
The twin piston primers activate automatically when delivery pressure falls below 150kpa
Siting considerations
Wind direction
Proximity to the incident
Proximity to the water supply
Good operating procedures
Panel direction
Pump operator’s view
Oncoming appliances
Park clear of power lines or trees that may be affected by the fire
3 steps after pump engaged
1 – Get water into pump. From tank.
2 – Water out to fire, hose, reel, roof monitor
3 – Revs/KpA
What is pump and roll
Only available on MK5
Need to use Auxillary pump.
CAn drive and use hose reel and ground monitors
