PP 003: Pumping Theory

Question 1

What actions can be considered when realising you have overrun the pump supply?
Five answers

Answer 1

Consider an increase in supply or new water source

Reduce number of jets

Reduce branch flow settings

Reduce appliance engine revs

Consider withdrawing crews

Question 2

What are the two types of pump found on front line pumping appliances?

Answer 2

Centrifugal pump

Positive displacement pump

Question 3

What are the two parts of a single stage, centrifugal pump?

Answer 3

Impeller

Volute

Question 4

What does the impeller do?

Answer 4

Imparts kinetic energy to the fluid. The impeller is the rotating component of the centifugal pump

Question 5

What does the volute do?

Answer 5

Converts the kinetic energy to pressure energy

Question 6

What three things can a centrifugal two stage pump do?

Answer 6

High volumes of water at low pressure

Low volumes of water at high pressure

Both high and low simultaneously

Question 7

What is the working pressure and flow rate of the hose reel?

Answer 7

115-150lpm at 35-40 BAR

Question 8

What is the capacity of the water tank?

Answer 8

1400 litres

Question 9

What is the capacity of the foam tank?

Answer 9

127 litres

Should only be filled to three of the four bars, around 90 litres, to prevent the breather tube becoming blocked

Question 10

How many litres per minute can a pump deliver?

Answer 10

Should be 4000lpm, but practically it can only deliver 2700lpm

Question 11

A sudden increase in the low pressure guage could indicate what?
Three answers

Answer 11

Branch being shut down

Kinks in the delivery hose

Vehicles or debris on the delivery hose

Question 12

A sudden decrease in a low pressure guage could indicate what?
Three answers

Answer 12

Branches being opened

Burst delivery hose

Appliance tank is empty

Question 13

What can cause momentary fluctuations in the low pressure guage readings?

Answer 13

Pulse spraying techniques

Question 14

Name the switches on the pump that are water related, not foam related?
Seven answers

Answer 14

Function (Master) button

PTO switch

Tank to pump switch

Autofill switch

Hose reel pressure switch

Hose reel right switch

Hose reel left switch

Question 15

What hoses should be used to augment supplies to the pump?

Answer 15

Twinned 70mm hose

Question 16

How do you get the optimum flow minder reading?

Answer 16

Switch off the autofill switch

Wait for the water level guage to drop to three bars

Switch the autofill back on

Read the flow minder guage

Question 17

What actions should be taken if a hydrant length bursts?

Answer 17

Give command ‘burst hydrant length’

Close the inlet valve of burst length

Monitor water levels, ask for reduction if necessary

When new hose is ready, give ‘knock off hydrant’ command

Change the burst length with the new hose

Give the ‘water on hydrant’ command

Open the inlet valve and monitor the flowminder

Question 18

What does the pressure release valve do?

Answer 18

Releases pressure in the hydrant length

Question 19

What should be done if the autofill valve fails?

Answer 19

Operate the emergency autofill bypass valve

Notify the IC or sector commander

After the incident, or as soon as possible, the appliance should be taken off the run

Question 20

How much water does the emergency autofill bypass valve deliver?

Answer 20

1000lpm