Chapter 2- Principles Of Pumping Flashcards
Maximum theoretical height to which it would be possible to lift water by suction
34 feet
Water under pressure is obtained from 1 of 3 principal sources for fire fighting:
1) Hydrants w/connecting supply mains from a MUNICIPAL PUMPING STATION
2) Hydrants w/connecting supply mains from an ELEVATED STORAGE RESERVOIR
3) Hose supply line(s) from 1 or more pampers as in a RELAY OPERATON
Maximum height to which water may be lifted in practice is from ___________
26-28 feet
Dependable operating lift for fire pumps in reasonable good condition should not be expected to exceed ___________.
15-20 feet
The _________ consists basically of one or more impellers mounted on a shaft rotating in a housing & is produced in 3 general classifications for fire service use:
Centrifugal
Single stage
Parallel-Series, &
Multi-Stage
In the _______ pump, quantity of discharge is directly proportional to the speed of the pump! and speed has no direct bearing upon the pressure developed other than as governed by the restriction of the oriface through which the quantity passes
Positive displacement pump
In the _________ pump! the quantity of discharge is also directly proportional to the speed of the pump when pumping at a constant pressure! but unlike the displacement pump! at constant quality.
Centrifugal
All priming systems & positive displacement pumps for rated fire service use must be capable of developing ______ vacuum
22 inches of Hg
For LAC, the capacity of discharge rate for the priming system requires that it be capable of “priming all capacity pumps”, including 1250 gpm, when operating at ______ within ________.
10 feet of lift
30 seconds
For a 1500 gpm pump, the priming time limit is ______ @ ____ feet lift.
45 seconds
10 feet lift
All relief valves & pressure operated governors are required to limit the pressure rise to a max of __________ net above the set pressure.
20 psi
Usually the pressure setting (of relief valve) is approximately ____ psi above the operating pressure.
5
When cavitation occurs, you should:(3)
1) Reduce discharge rate
2) use a larger suction line, or
3) Lower the lift
When drafting, a lift not in excess of _______ is preferable although necessity may require greater lift on occasions.
10-12 feet
When setting up for draft, attach rope to suction strainer & submerge strainer end of hose in body of water. If possible, strainer should be submerged @ least _____ and should not be within ___ of the bottom.
18”
12”
