Pumps and Motors Flashcards

1
Q

___ is measured in feet.

A

Head

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2
Q

It is best to use a ___ type of impeller for pumping water with a low volume of solids.

A

Closed

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3
Q

Atmospheric pressure at sea level is equal to ___ feet of water head.

A

34 (33.9) ft.

14.7 psi / 0.433 ft/psi = 33.9 ft

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4
Q

The study of fluid in motion is called ___.

A

Hydraulics

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5
Q

___ (flow rate with units of gpm) is plotted on the horizontal axis of a pump curve.

A

Capacity

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6
Q

___ (with units of feet) is plotted on the vertical axis of a pump curve.

A

Head

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7
Q

The resistance of a material to the flow of electrical current is measured in ___.

A

Ohms

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8
Q

The speed of a variable pump should be monitored to prevent ___ from occuring.

A

Cavitation

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9
Q

The __ ___ must be determined first when designing a pump station.

A

Head requirements

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10
Q

Centrifugal pumps with ___ ___ impellers are the type most commonly used by water systems.

A

Radial flow

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11
Q

___ ___ is the amount of energy in feet required to overcome resistance to flow in a pipe.

A

Friction head

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12
Q

An ___ ___ pump has the ability to rotate it’s discharge 360 degrees.

A

End suction

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13
Q

The temperature of a centrifugal pump motor ___ should be checked with a thermometer once a ___.

A

Bearings, month

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14
Q

The ___ ___ houses the packing and lantern ring in a centrifugal pump.

A

Stuffing box

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15
Q

The ___ ___ is at the top of the stuffing box and can be tightened or loosened to control packing leakage.

A

Packing gland

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16
Q

A ___ ___ is used to prevent air leakage along the pump shaft when it is operating under suction lift conditions.

A

Lantern Ring

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17
Q

A ___ ___ is used in place of packing when the pump suction pressure is equal to or greater than 60 psi.

A

Mechanical Seal

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18
Q

The heart of the pump is called the ___.

A

Impeller

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19
Q

The first oil change on a newly installed pump should be performed after ___ month(s) of opertation.

A

1

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20
Q

Bearings that maintain the radial positioning of a pump shaft are called ___ ___.

A

Radial Bearings

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21
Q

Pump shaft packing is usually replaced when tightening the packing gland does not reduce shaft ___ or the packing gland can no longer be ___.

A

Leakage, tightened.

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22
Q

A ___ changes alternating current to direct current by allowing the electric current to flow in one direction but blocking flow in the opposite direction.

A

Rectifier

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23
Q

Bearings on a line shaft pump can be lubricated with either ___ or ___.

A

Oil, Water

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24
Q

Pump shaft ___ is designed to wear out over time during normal use.

A

Packing

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25
Q

Manufacturers typically design pumps such that the first critical speed is at least ___% higher or lower than rated speed.

A

20%

26
Q

___ ___ is the theoretical angular velocity that excites the natural frequency of a rotating object, such as a shaft.

A

Critical Speed

27
Q

To make instillation easier, impeller wear rings can be ___.

A

Heated

28
Q

The flow capacity of a centrifugal pump is ___ related to total head.

A

Directly

29
Q

The amount of liquid that can be raised by a given pressure is called ___ ___.

A

Pressure head

30
Q

When water recirculates within a centrifugal pump casing around the impeller due to a blockage of the pump discharge, the recirculation is called ___.

A

Slip

31
Q

___ head is the amount of energy in feet that the pump supplies to a fluid.

A

Pump

32
Q

A ___ ___ is a horizontal load, that runs parallel to a pump shaft.

A

Thrust load

33
Q

A lantern ring is also called the ___ ___.

A

Seal cage

34
Q

The impeller of a centrifugal pump is “___” to the shaft so that it rotates with the shaft.

A

“keyed”

35
Q

A ___ valve usually serves as the pump suction isolation valve.

A

Gate

36
Q

In a split case centrifugal pump, the ___ of stages is equal to the number of ___ sized impellers.

A

Number, differently

37
Q

As the total head of a system increases, the volumetric flow rate that a centrifugal pump delivers is reduced ___.

A

Proportionately

38
Q

___ and ___ forces determine the behavior of electricity.

A

Electric, magnetic

39
Q

If a pump looses its prime because the suction line has an air pocket, the operator should open the ___ piping air ___ valves.

A

Suction, bleed-off

40
Q

Ohms’ law says that ___ = (amps) x (ohms)

A

Volts

41
Q

The height a liquid can be raised vertically by a given pressure is called ___ head.

A

Pressure

42
Q

Pressure gauges connected to both suction and discharge sides of a pump should be connected to the taps ___ on the pump to determine ___ pressure.

A

Supplied, differential

43
Q

Bearings should not be lubricated with ___ ___ (made from animal fat) because they form acids when they begin to break down.

A

Animal oil

44
Q

Inspection of the shaft and coupling alignment should be performed every 6 months or ___, if a problem is suspected.

A

Immediately

45
Q

Electrical conductors usually fail because of ___ failure.

A

Mechanical

46
Q

The current rating of a fuse should be ___ to or slightly ___ than the current rating of the circuit device or that it protects.

A

Equal, larger

47
Q

A ___ stores energy and consists of a pair of metallic plates that are separated by an insulated material called a dialectic.

A

Capacitor

48
Q

___ is a condition where a pump is subject to frequent cycling due to pressure surges that effect the pump controller.

A

Racking

49
Q

A ___ ___ is used to measure the average power of a load over a specific time interval.

A

Demand meter

50
Q

A ___ ___ is frequently used on large equipment to check whether all the current entering the system comes out of the system.

A

differential relay

51
Q

A ___ ___ is used on synchronous motor starters to sense when the motor has reached synchronizing speed.

A

Frequency relay

52
Q

Thermal ___ ___ are placed on each phase of a power supply to open up a control circuit and stop a motor, if the current becomes excessive.

A

overload relays

53
Q

A wound-rotor ___ ___ and controller will provide for a “soft start” to a motor.

A

induction motor

54
Q

Insulators usually fail because of excessive ___.

A

heat

55
Q

Atmospheric pressure at sea level is equal to ___ feet of water head (14.7 psi / 0.433 ft/psi = 33.9 ft.)

A

34

56
Q

At sea level, the total vacuum is ___ inches of mercury (often round to ___ inches).

A

29.92, 30

57
Q

If a centrifugal pump with a single volute is operated at more than ___% of it’s design capacity, an excess radial load will result, causing premature bearing failure.

A

120%

58
Q

___ head is the amount of energy in feet that a pump supplies to a fluid.

A

Pump

59
Q

Motor-winding insulation should exhibit at least ___ ___ of resistance.

A

1.0 megohm

60
Q

A ___ coupling is easy to install and remove.

A

split

61
Q

Although some phase imbalance will occur in all electrical systems, it should not exceed ___.

A

5%

62
Q

A ___ relay is frequently used to detect ___ ___ and initiate an automatic switchover to another power supply.

A

voltage, power loss