pumps for private water systems Flashcards
1
Q
how is a pump able to lift water from a well
A
by creating a partial vacuum in the pumping chamber
2
Q
how does the diameter of a well affect pumping capacity
A
by limiting the size of pump you can install
3
Q
what is the maximum theoretical lift of a centrifugal pump used as a suction pump
A
close to 34 feet
4
Q
why is a jet pump capable of a greater suction lift than a centrifugal pump
A
jet pumps are better at developing negative pressure than centrifugal pumps
5
Q
what is the difference between a shallow well and a deep well
A
depth to the pumping level of the well
6
Q
how does the altitude of a pump installation affect pump selection and installation methods
A
higher elevations do not have as much atmospheric pressure
7
Q
how does friction loss affect the use of a suction pump
A
by reducing the amount of work done by atmospheric pressure
8
Q
what condition may cause cavitation for a centrifugal pump
A
pump is working at maximum lift capacity
9
Q
what are centrifugal pump suction lines installed with positive grade from the well to the pump inlet
A
for better air elimination when priming
10
Q
how may drawdown in a well affect an aquifer
A
drawdown can allow the aquifer to start releasing sand
11
Q
why should pump capacity be matched to well capacity
A
to prevent aquifer problems from developing
12
Q
when is a well considered to be a deep well
A
when the wells pumping level is deeper than 24 feet
13
Q
why are some jet pumps called convertible jet pumps
A
the jet assembly can be removed from the pump and placed in a well
14
Q
which piston pump can be offset from the top of a well
A
shallow well piston
15
Q
which pumps may produce enough pressure to damage a pressure system
A
reciprocating and submersible pumps
16
Q
what are helical screw pumps usually used for
A
pumping slurries and sludges
17
Q
when a shut off valve is placed on a tank tee for a residential installation which side of the tank tee should i be placed on
A
outlet of tank tee
18
Q
what is the pressure output of submersible pump impeller stage
A
9psi per stage
19
Q
why does a submersible pump require a check valve at its outlet
A
to stop water from draining out of the drop pipe through the pump
20
Q
what types of impellers are used on centrifugal pumps
A
closed, semi closed, open
21
Q
what device is used on the outlet of two pipe jet pumps to allow the pump to produce the most water possible
A
a flow control fitting or valve
22
Q
list the six components of a private water system
A
-electric motorized pumping unit
-pressure tank
-air volume control
-pressure switch
-relief valve
-foot valve
23
Q
what is the correct ratio of water to air in a standard pressure tank
A
1/3 air and 2/3 water
24
Q
a standard galvanized pressure tank that has lost its air charge is said to be
A
waterlogged
25
a standard galvanized pressure tank that contains 33.3% air and 66.6 % water will release 20% of its water before the pump must start again. this volume of water is called
usable water
26
an installation that requires air to be replenished in the pressure tank requires an air volume control. the two most common types of air volume control are
float type and diaphragm
27
the electrical device that turns the pump on and off is called a
pressure switch
28
a _______ is a type of vertical lift check valve on the suction end of the piping in the well
foot valve
29
define the term HEAD
a pressure expressed in terms of height of a water column in feet
30
define the term pressure
a measurement expressed in unit of weight per area, for example, pounds per square inch.
31
a pump works by creating a _______ on the inlet side of the pump, which allows atmospheric pressure to force water into the suction line
negative pressure
32
one pound of pressure will lift a column of water _____
2.31 feet
33
to convert feet of head to psi, multiply by ____
.433
34
list four types of pressure tanks
-standard galvanized tank
-floating disk
-diaphragm
-bladder
35
an air volume control is used on a bladder type pressure tank true of false
false
36
there is no contact between the water and the tank when the _______ type of pressure tank is used
bladder
37
what are the five steps for selecting and sizing of a private water system
-discharge pressure
-suction pressure
-pump capacity
-two pump system
-type of pump
38
list two things that will happen if the wire size to the pump is too small to adequately meet the power requirements
1 the expected life of the electric motor will be reduced
2 electrical energy will be lost in the form of heat in the feeder circuit
39
list two reasons why a well must be protected from surface water
1 surface water could contaminate a well
2 surface water could puddle and freeze, damaging pipe and other components
40
list four different types of wells
-drilled
-driven or jetted
-dug
-bored
41
you notice a reduction in the amount of water available from the well and a scale formation is present on the surface of the plumbing fixtures. what is the problem and how would you correct it
a reduction in the amount of water available from the well and mineral building up on plumbing would be caused by mineral scale building (encrustation) on a perforated well casing. this problem is corrected by cleaning the pump and acidizing of the well by a licensed well driller
42
how much water is needed per person on a daily basis
60 US gals (230 litres)
43
why does the amount of water needed by hogs vary so greatly
gender, size differences, and lactating status create varying demands
44
what is the rule of thumb for sizing sprinkler lines based on national fire protection standard 13D
3/4" to supply one sprinkler,
1" to supply two sprinkler heads
45
how is freeze protection provided for a cistern that cannot be buried deeply enough
by placing insulation suitable for the purpose over the tank
46
why does a buried cistern require a vent line for the cistern
the vent allows the cistern to operate under atmospheric pressure conditions
47
after an uncoated concrete cistern is filled. you observe the water level has lowered in the cistern, even though no one has used any water. what causes this?
uncoated concrete is porous and will allow water to soak into it lowering the cistern water level
48
why is the vent terminal of a cistern arranged to point back toward the ground
so precipitation cannot enter the vent
49
why is drinking water with no additional treatment rarely collected directly from lakes
the water may appear to be clean but could be contaminated by animals using the watershed for the lake
50
why are water intakes placed at various levels in a lake
to allow an operator to collect the cleanest possible water from a lake during periods of the year when the lake turns over due to temperature differential
51
how are springs classified into three different categories
by how the water from the spring comes to the ground surface
52
when placing an impoundment box, over a spring to provide for water collection, how is the spring opening prepared?
with as little disturbance as possible to the opening
53
what factors influence waters ability to dissolve soluble material
solubility of material, time of contact, ph of water, temperature of water
54
how does a well screen filter material out of water coming from an
unconsolidated aquifer
the screen relies on bridging of larger material near the screen to filter finer material
55
what is well development
the cleaning of an aquifer by a drill rig to ensure the well water is as clean as possible
56
how are wells generally sorted as to their type?
by the type of equipment that was used to make them
57
what is the definition of a positive displacement pump
it has a defined volume for every cycle/revolution
58
what is the different between a single acting piston pump and a double acting piston pump
-single acting moves water in one direction only
-double acting moves water in both directions
59
what is the definition of a non positive displacement pump
no defined volume for each revolution or cycle
60
how does a centrifugal pump work
as water moves through the impeller the water velocity causes a lower pressure at the inlet
61
what happens when you increase the length of the impellers ? what happens when you increase the width of the impellers?
(with the samne RPM speed)
-longer impellers will result in higher pressure
-wider impellers will result in higher volume
62
what would happen if you put two centrifugal pumps in series? in parallel?
-series will increase the pressure
-parallel will increase the volume
63
what is the definition of a shallow well? a deep well?
-shallow well can be used up to aprox 25' in depth
-deep well can be used up to 250' in depth
64
what is drawdown level?
the level the water will fall to once the pump starts and moves water
65
what is the most common type of shallow well pump?
the jetted shallow well pumpwh
66
at is a jet pump? what is the difference between shallow well jet pump and deep well jet pump?
-jet pumps use an ejector and venturi to increase the negative pressure at the inlet
-the difference is the location of the jet
67
what is the theoretical suction lift of a shallow well jet pump? what is the practical suction lift?
34' max theoretical
25' max practical
68
how high can each of these two pumps lift water? what determines the height each can lift water?
depends on atmospheric pressure 14.73 at sea level
69
how many pipes run into the water in a shallow well jet pump installation? how about in a deep well installation?
-shallow well only needs one pipe
-deep well needs 2 pipes
70
explain how the ejector (jet assembly) works in a deep well pump?
the jet is down in tthe well where it can produce max gain
71
where would the jet assembly be located for a shallow well jet pump? how about for a deep well jet pump?
-in a shallow well jet the jet is located on the nose of the pump
-in the deep well, the jet is in the well above the suction inlet
72
there are two pipes that run down into the water in a deep well jet pump installation. what would the sizes typically be? what are the names of the two pipes?
the suction line is larger than the drive line normally by one pipe size. 1-1/2' and 1-1/4' typically
73
a deep well jet pump diverts some of the water that has drawn up from the well right back down into the well. what is the name of the valve that adjusts how much water goes to the house , and how much goes back down into the well?
"flow control valve"
-optimize for max gain
-use a gauge to set up the valve
74
if a pump created 30psi, how high could it lift water (ignoring friction)
use 30 x 2.31 or 30 divided by .433
75
a shallow well jet pump is installed directly above a well. what detiermines the maximum height above the well at which the pump can be located?
governed by the psa (absolute pressure) 14.73
76
what determines the size of the suction pipe for a shallow well jet pump
the type of pipe/ gpm capacity/ length of line
77
what is it called when the pump starts and stops frequently? how can you prevent this from happening?
-short cycling
use a larger pressure tank
78
what is the function of a pressure switch? what is the typical cut in and cut out pressures of a pressure switch?
-it keeps the system under constant pressure
-typical setting cut in at 25 psig and cut out at 35 psig
79
what is cavitation and what causes it?
cavitation is the lack of pressure at the suction inlet causing the formation of vapour bubbles to occur
80
what are the three steps which must be taken before starting a pump?
-prime the pump
-check for leaks
-check for free moevement
81
a water main had a pressure of 60psi going through it. it has to serve a building in which the highest fixture requiring water is 45 feet above the main. the fixture is a lavatory. there is a friction loss of 20psi. is there enough pressure in the main to get the water to the fixture and have the fixture operate properly?
60psi - (45 x .433) -20 = 20.515psig.
yes
82
how does a submersible pump create enough pressure to move water long vertical distances?
-multistages that add pressure each time it goes through an impeller
83
what should be installed in the discharge line from a submersible pump to prevent the line from losing water
a foot valve/ check valve is incorporated into the pump at the top, just below the suction line
84
what is the function of an air volume control
to maintain the proper amount of air in the pressure tank
85
a fixture is located 6 meters above a pneumatic tank and pump. it takes 100kpa to function. the system loses 30kpa to friction from the tank to the fixture. what should the minimum pressure switch setting be in order for the system to work properly
100kpa + (6m x 10kpa/m) + 30 kpa = 190kpa
86
what type of pump is a booster pump in a highrise building? when is it needed
?
-impeller type
-to provide enough pressure for the upper floors
87
why are centrifugal pump suction lines installed with positive grade from the well to the pump inlet?
for better air elimination when priming
88
if a pump has a total head of 240 feet and a suction head of 19 feet, what would be the discharge head
240 - 19 = 221
89
the discharge side of a jet p[ump has a polyethylene water service pipe connected to it. how would the polyethylene pipe be attached to the outlet of the pump?
use a barbed adapter + 2 stainless hose clamps ( alternate direction of gear)
90
what phase are large high amperage motors usually supplied with?
3 phase
91
what would be the colours of a 120 volt three wire cable?
black, white , and green
92
how would you suppoert 400 foot submersible pump
it may be supported by the pitless adapter
93
what is the diameter of a typical residential submersible well pump? and what size casing would be need to accommodate it ?
3-5/8" is a very common industry size pump diameter. this pump fits into 4 or 6 inch well casing
94
what is a convertible jet pump? when is it required to move the jet assembly from the pump and install it into the well?
a pump that can be used fopr shallow well use or when need, the jet can be moved down into the well for deep well use over 25' in depth
95
what factors will govern how many gallons of water will be moved by a centrifugal pump
friction is the obstacle to moving water so the pressure developed must overcome this friction. and then flow will begin. so calculate total head and gpm's needed.
96
what is a torque arrestor used for? where is it located and how is it secured to the pipe?
it prevents damage by controlling flex movement of the pipe against the pipe walls caused by the starting and stopping action of the submersible pump. uses hose clamps to secure to the suction line above the pump
97
what is a pump curve used for? how do you read a pump curve?
all pump manufacturers provide a pump curve to indicate the capacity of the pump. it is used to predict pump output based on the feet of head in the system. feet of head is on the vertical scale and GPM is given on the horizontal scale
98
what types of pumps require priming
any pump with an impeller must be primed with water before it can be started. the suction will also need to be primed so the pump does not become air bound
99
what type of electrical reading would give any clues about how a pump is running?
measure the current draw using a clamp or forked multimeter, these use inductive pickups so they are much safer to use. too much current usually means too high of a load. too little current load is usually due to no water movement
100
what does the term locked rotor amperage draw refer to?
a stalled rotor, can be cause by a jammed impeller. but the load is very high and will soon trip a breaker or trip a fuse
101
what is the function of an air volume control? where is it used ?
only used on pressure tanks without a diaphragm, it keeps the air volume inside the tank at the correct level required to the air being absorbed by the water in the tank
102
