Pumps And Primers Flashcards
What is priming?
The removing of air in the pump and replacing it with wate
What can’t a centrifugal pump do that a positive displacement pump can?
Pump gasses
Why must we flush all hydrants?
To prevent stones and debris damaging and effecting the impeller/ pump efficiency
What is the snail shell shaped part?
Volute
Give an example of a 3 stage centrifugal pump?
The Hp hose reel pump on the MAN
What is the pro and con for centrifugal pumps?
Pro-the move a lot of water and are simple.
Con- can’t supply enough pressure for hosereels
Name 4 types of pump?
Centrifugal,peripheral, ejector, positive displacement
Another name for peripheral pump?
Regenerative
What is the advantage of peripheral/regenerative pumps?
It allows water to be delivered at both high and low pressures simultaneously
Required pump speed for hose reels?
3000rpm
What is an ejector pump?
Used to pump water and gases with an existing flow of water
When are submersible type ejector pumps commonly used?
Out of water from depths greater then the maximum practical suction lift
What is the principle of operation of an ejector pump known as?
The Venturi principle
What is the word used to describe surrounding water to join the propellants stream?(ejector pumps)
Entrained
What type of pump is the stirrup pump?
Positive displacement
Name two types of PD pumps?
Stirrup, peristaltic
How are the LPPs primed?
Using an exhaust gas ejector
How much air/ water can a reciprocating primer discharge every revolution?
1L
How do you know when a reciprocating primer as got rid of all the air?
A popping sound before the cam is disengaged
How do you know when the exhaust gas ejector primer has got rid of all air?
When clouds of steam issue from the exhaust
What is a pumps nominal output/duty point?
The pressure at which the pump is most effective. E.G:2250L/min at 7 bar
What is the maximum water relay pressure?
10 bar
Why should the 1st booster pump be closer to the base pump?
To compensate for the reduced output after suction.(reduced by 2 lengths)
Why should the incident ground pump be independent?
Branch ops won’t be effected by fluctuations in relay
Pump has a water reserve
Before charging the hose,Why should a spare delivery be left open when part of a relay?
To release air, to save releasing all air from all pumps at the fireground pump
What pressures should relay pumps be working at?
7 bars
How could you cool the LPP if used as the fireground pump?
Attach a dividing breech and trickle away some water
What is Water carrying/shuttling?
When distance between water source and fireground is very big. But dose not warrant a relay
What are 3 methods of water shuttling/carrying?
Appliances, flexitainrs,water carrier
What can a flexitainer hold?
5000L
What does the water carrier hold?
10000L
Steps for priming the LPP?
- Open manual priming valve
- start engine
- full throttle
- pull up priming lever
- when delivery gauge reads 1bar, and steam and water come out release.
- open delivery
- close priming valve
Which principle is used to prime the LPP?
Venturi
