Pumps and Motors

Question 1

___ is measured in feet.

Answer 1

Head

Question 2

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

Answer 2

Closed

Question 3

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

Answer 3

34 (33.9) ft.

14.7 psi / 0.433 ft/psi = 33.9 ft

Question 4

The study of fluid in motion is called ___.

Answer 4

Hydraulics

Question 5

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

Answer 5

Capacity

Question 6

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

Answer 6

Head

Question 7

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

Answer 7

Ohms

Question 8

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

Answer 8

Cavitation

Question 9

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

Answer 9

Head requirements

Question 10

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

Answer 10

Radial flow

Question 11

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

Answer 11

Friction head

Question 12

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

Answer 12

End suction

Question 13

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

Answer 13

Bearings, month

Question 14

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

Answer 14

Stuffing box

Question 15

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

Answer 15

Packing gland

Question 16

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

Answer 16

Lantern Ring

Question 17

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

Answer 17

Mechanical Seal

Question 18

The heart of the pump is called the ___.

Answer 18

Impeller

Question 19

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

Answer 19

1

Question 20

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

Answer 20

Radial Bearings

Question 21

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

Answer 21

Leakage, tightened.

Question 22

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

Answer 22

Rectifier

Question 23

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

Answer 23

Oil, Water

Question 24

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

Answer 24

Packing

Question 25

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

Answer 25

20%

Question 26

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

Answer 26

Critical Speed

Question 27

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

Answer 27

Heated

Question 28

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

Answer 28

Directly

Question 29

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

Answer 29

Pressure head

Question 30

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

Answer 30

Slip

Question 31

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

Answer 31

Pump

Question 32

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

Answer 32

Thrust load

Question 33

A lantern ring is also called the ___ ___.

Answer 33

Seal cage

Question 34

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

Answer 34

"keyed"

Question 35

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

Answer 35

Gate

Question 36

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

Answer 36

Number, differently

Question 37

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

Answer 37

Proportionately

Question 38

___ and ___ forces determine the behavior of electricity.

Answer 38

Electric, magnetic

Question 39

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

Answer 39

Suction, bleed-off

Question 40

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

Answer 40

Volts

Question 41

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

Answer 41

Pressure

Question 42

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

Answer 42

Supplied, differential

Question 43

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

Answer 43

Animal oil

Question 44

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

Answer 44

Immediately

Question 45

Electrical conductors usually fail because of ___ failure.

Answer 45

Mechanical

Question 46

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

Answer 46

Equal, larger

Question 47

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

Answer 47

Capacitor

Question 48

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

Answer 48

Racking

Question 49

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

Answer 49

Demand meter

Question 50

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

Answer 50

differential relay

Question 51

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

Answer 51

Frequency relay

Question 52

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.

Answer 52

overload relays

Question 53

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

Answer 53

induction motor

Question 54

Insulators usually fail because of excessive ___.

Answer 54

heat

Question 55

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

Answer 55

34

Question 56

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

Answer 56

29.92, 30

Question 57

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.

Answer 57

120%

Question 58

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

Answer 58

Pump

Question 59

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

Answer 59

1.0 megohm

Question 60

A ___ coupling is easy to install and remove.

Answer 60

split

Question 61

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

Answer 61

5%

Question 62

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

Answer 62

voltage, power loss