PUMPS AND PRIMERS

Question 1

definition of a pump

Answer 1

mechanical device driven by an external source used for transmitting energy to fluids

Question 2

what must a pump be?

Answer 2

• self contained
• lightweight
• can handle large quantitates of water
• produce high pressure
• reliable
• easy to operate/maintain

Question 3

what are the types of pumps

Answer 3

• Pos. displacement
• Centrifugal
• Peripheral
• Ejector

Question 4

state characterises of Pos displacement pumps

Answer 4

• pump liquids/gasses
• effeciant (85%)
• no priming needed

Question 5

can centrifugal pumps work with water/gas and what flow does it provide?

Answer 5

no just water!

-constant flow (needs priming device to remove air from system)

Question 6

what is the PTO

Answer 6

POWER TAKE OFF

Question 7

what are centrifugal pumps used in

Answer 7

mian pumps/ LPP (light portable pump)

Question 8

how do centrifugal pumps work

Answer 8

water gets thrown to outside of pump casing (volute) by central spinning wheel (impeller). the faster the impeller rotates=higher pressure

Question 9

what does the volute do

Answer 9

channels water from periphery of impeller to the outlet. reduces velocity of water as it passes. reduced turbulance pf water caused by impeller

Question 10

what is the water flow in centrifugal pump

Answer 10

enters eye of the pump, spinning impeller imparts energy driving water to edges, water enters volute increasing pressure, (lost water in centre is resupplied by pressure fed/suctioned water)

Question 11

characteristics of centrifugal pumps

Answer 11

• at any speed where no flow is present, pressure is @max
• pressure decreases as delivery valves open and flow increases
• when pump speed is high, pressure/flow is high
• when suction lift increases pressure/flow decreases

Question 12

advantages of centrifugal pumps

Answer 12

• simple to maintain
• can be run against closed deliveries without damage
• light/compact (relative to output)
• driven directly from internal combustion engine

Question 13

disadvantages of centrifugal pumps

Answer 13

• needs separate priming device to work from open water

- less efficient that Pos displacement pumps

Question 14

define primer

Answer 14

mechanical device used to evacuate a volute

Question 15

what are peripheral pumps used on

Answer 15

used mainly as hose reels (allow higher pressures due to smaller centrifugal pumping unit)

Question 16

can peripheral pumps produce higher pressures @ relatively low running speeds

Answer 16

YES

Question 17

what is the DUTY POINT of peripheral pumps

Answer 17

227 7pm @ 24bar

Question 18

what are operating principles for peripheral pumps

Answer 18

• water enters a tube surrounding guide vanes, drops down to base, thrown out several times to peripheral
• with each spiral action adding force/pressure to the water prior to it leaving via outlet

Question 19

what are the pump guages

Answer 19

• LPD (low pressure displacement)
• Compound (pos/neg)
• High pressure delivery
• Oil/water delivery

Question 20

what are pressure gauges output

Answer 20

• Low pressure (jets)

- High pressure (hose reels)

Question 21

BRANCH OUT OF CONTROL (process)

Answer 21

-firefighter that ids. issue shouts “branch out of control”
-pump operator immediately lowers revs on pump or if multiple hose lines are in use, start closing effected delivery
-2 firefighters (visors down) crawl along hose line to branch (hands on hose line)
-@branch its held in position and closed down!
(Type A branches, either lay on hose until shut off or pick up carefully and resume normal position)

Question 22

What are the pump rates for a Hose reel, 45J and 70mmJ?

Answer 22

Hose reel= 115l/m

45mmJ= 450l/m

70mmJ= 900l/m