Liberty Distribution Exam Prep 1

Front 1

From the list below select the type of pipe joint that permits flexible pipe alignment, is inexpensive to manufacture, and is easy to assemble.

Back 1

Push-on joint

Front 2

According to AWWA Standard C651, disinfecting a newly installed water main requires 24-hour exposure to minimum free chlorine residual of ______ mg/L?

Back 2

25 mg/l

Front 3

From the list below, select the water quality parameter that requires a grab sample because it cannot be collected as a composite sample.

Back 3

Ph

Front 4

When measuring free chlorine residual, what method is the quickest and simplest?

Back 4

DPD color comparator

Front 5

What type of water storage facility is most likely to contain non-potable water?

Back 5

Emergency storage tank

Front 6

What type of temperature sensor uses a semi-conductive material?

Back 6

Thermistors

Front 7

What type of temperature sensor uses a semi-conductive material?

Back 7

Tensile and flexural strength

Front 8

From the list below, choose the type of pipe that would most likely collapse or become distorted under a partial vacuum.

Back 8

Steel

Front 9

The speed of a variable speed pump should be monitored to prevent __________ from occurring.

Back 9

Cavitation

Front 10

Concrete piping using bell and spigot type joints is appropriate for installation:

Back 10

In all locations

Front 11

New polyvinyl chloride pipe has a C-value of about:

Back 11

150+

Front 12

The ideal residential water system pressure ranges from:

Back 12

50 to 75 psi

Front 13

The disinfectant residual entering the distribution system from a water treatment facility must not be less than:

Back 13

0.2 mg/L for more than 4 hours during periods when the system is serving water to the public

Front 14

Protecting steel pipe from external corrosion is best accomplished by:

Back 14

Cathodic protection

Front 15

From the list below, select a type of joint for polyvinyl chloride piping.

Back 15

Bell and spigot type

Front 16

What type of pipe joint consists of two machined surfaces?

Back 16

Flanged joint

Front 17

For systems that only use surface water, what must be measured at the same time and at the same sampling points in the distribution system that total coliforms are sampled?

Back 17

Residual disinfectant concentration

Front 18

The inlet thread on a standard AWWA corporation stop is called a ___________ thread.

Back 18

Mueller thread

Front 19

From the list below, select a type of joint for ductile iron piping.

Back 19

Restrained joint

Front 20

Fire hydrants should not be installed on a water main that is less than ______ inches in diameter.

Back 20

6

Front 21

Bell and spigot connecting pipe (push-on joint) is easier to lay with the bells facing uphill when the main is being laid on a slope steeper than:

Back 21

6%

Front 22

Packing is designed to:

Back 22

wear and deteriorate with normal use

Front 23

Full lengths of 48-inch ductile iron pipe using push-on joints has a maximum deflection of ____ degrees.

Back 23

3 degrees

Front 24

What type of valve is used to prevent the collapse of a pipe?

Back 24

Air-and-vacuum relief valve

Front 25

What is the main function(s) of the meter yoke?

Back 25

Ensure proper alignment and support for meter

Front 26

A plat is a:

Back 26

Map

Front 27

Which type of temperature measuring device uses two wires of different materials?

Back 27

Thermocouple

Front 28

What is one advantage chlorine has over other disinfectants?

Back 28

Chlorine has a persistent residual.

Front 29

What type of pipe is durable, strong, has high flexural strength, is corrosion resistant, and is easily tapped?

Back 29

Ductile iron

Front 30

Which of the following type of chlorine is called HTH?

Back 30

Calcium hypochlorite

Front 31

A movable follower ring is used with a:

Back 31

Mechanical joint

Front 32

Average soils require an angle of repose of ________ to prevent a trench cave-in.

Back 32

1:1

Front 33

Who should the water system contact to ensure proper disposition of groundwater from a pipe trenching project?

Back 33

Local regulatory agency

Front 34

Select the type of joint that can be used for steel piping from the choices below?

Back 34

Rubber gasket joint

Front 35

A __________ valve is a special kind of check valve.

Back 35

Foot

Front 36

A __________ valve is a special kind of check valve.

Back 36

Foot

Front 37

A water sample collected for chlorine analysis must be analyzed within _____ minutes of collection.

Back 37

15

Front 38

What is the most common method of feeding chlorine gas?

Back 38

Vacuum feeder

Front 39

What is the "heart" of a pump called?

Back 39

Impeller

Front 40

The correct protective methods for backflow-prevention devices in order of most effective to least effective is:

Back 40

air gap,RPZ, DCVA,and VB.

Front 41

What is used to stop air leakage into the casing around a pump shaft when the pump is operating under suction lift conditions?

Back 41

Lantern ring

Front 42

The bearings that maintain the radial positioning of a pump shaft are called:

Back 42

Radial bearings

Front 43

What is the best mechanical compacting equipment to use for sand in shallow lifts?

Back 43

Hand-controlled plate tampers

Front 44

When following the partial fill (two-step) method for disinfecting a water storage tank, the initial dosage of 50 mg/L of available chlorine should be held in the partially filled tank for:

Back 44

At least 6 hours

Front 45

When installing new water main pipe, the trench excavation should extend:

Back 45

Just ahead of the pipe installation

Front 46

Casing pipe used to enclose a large diameter water main under a railroad crossing should have a diameter that is _____ to _____ inches larger than the outside diameter of the water main bells.

Back 46

2 to 8

Front 47

Compression fittings used with copper or plastic tubing seal by means of a:

Back 47

compressed beveled gasket

Front 48

All sensors that respond to liquid pressure will perform poorly if:

Back 48

Air enters the sensor

Front 49

A water system must report a positive fecal coliform test to the primacy agency within:

Back 49

24 hours

Front 50

Samples to be tested for coliforms are collected in 125 mL sterile plastic bottles that contain

Back 50

sodium thiosulfate

Front 51

The primary criteria for sizing water mains is:

Back 51

adequate fire flow at an appropriate pressure

Front 52

Where is the lantern ring and packing held in a centrifugal pump?

Back 52

Stuffing box

Front 53

What is the detention time requirement when disinfecting a storage tank with sodium hypochlorite by filling the tank with chlorinated water so that 10 mg/L of free chlorine remains following the required contact time?

Back 53

24 hours

Front 54

The lantern ring is also called the:

Back 54

Seal cage

Front 55

Which is the Maximum Contaminant Level for total trihalomethanes (TTHMs)?

Back 55

0.080 mg/l

Front 56

Following maintenance on a water storage tank, the tank must be disinfected and a ___________ test must be performed. The bacteriological test must be negative before the tank is placed in service.

Back 56

Coliform test

Front 57

A _________ joint is primarily used in exposed locations.

Back 57

Flanged

Hint 57

I

Front 58

Push-on or mechanical joints connecting ductile iron pipe are used:

Back 58

where flexibility is required

Front 59

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

Back 59

Rectifier

Front 60

A __________ joint is not flexible and therefore should not be buried.

Back 60

Flanged

Front 61

Which agency sets legal limits on the concentration levels of harmful contaminants in public water systems?

Back 61

United States Environmental Protection Agency

Front 62

From the list below, choose a type of joint used to connect ductile iron piping?

Back 62

Push-on joint

Front 63

What is the purpose of an altitude valve used on water storage tanks?

Back 63

To stop the flow of water into the tank when it is full

Front 64

From the list below, choose which valve will have the highest head loss when fully open?

Back 64

Globe valve

Front 65

If poor soil conditions require bringing in special bedding material, the new material should not contain more than _____ % clay or silt.

Back 65

12%

Front 66

A(n) _______ _______ type of pump has the ability to rotate its discharge 360°.

Back 66

End suction

Front 67

Fire flow requirements dictate that water mains smaller than 6 inches should only be used:

Back 67

To complete a grid

Front 68

What is the best mechanical compacting equipment for deep narrow trenches so workers don’t have to enter the trench?

Back 68

Boom-mounted plate tampers

Front 69

To make installation easier, impeller wear rings can be:

Back 69

Heated

Front 70

Data manipulations using the basic elements of automated mapping, facility management, and geographic information systems are often used for distribution system _________ and ________.

Back 70

modeling and analysis

Front 71

From the choices below, select the type of joint used for concrete piping.

Back 71

Bell and spigot type

Front 72

What is the required bolt torque for a mechanical-joint on a standard 48-inch ductile-iron water main?

Back 72

120 to 150 ft-lb

Front 73

First draw samples for the analysis of lead and copper water must be collected from taps where the water has stood motionless in the plumbing for at least _______ hours.

Back 73

6

Front 74

What type of valve usually serves as the pump suction isolation valve?

Back 74

Gate

Front 75

From the valves listed below, choose which type of valve operates similar to a diaphragm valve.

Back 75

Globe valve

Front 76

Areas requiring high fire flow capacity require the minimum static pressure to be:

Back 76

35 psi or greater

Front 77

Hypochlorous acid is:

Back 77

A weak acid

Front 78

A _________ __________is a horizontal load, that runs parallel to a pump shaft.

Back 78

Thrust load

Front 79

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

Back 79

Pump

Front 80

How many feet of water will equal the atmospheric pressure at sea level?

Back 80

34

Front 81

The best disinfectant to use for disinfecting long lengths of large diameter pipe is:

Back 81

Chlorine gas

Front 82

What is the most common type of centrifugal pump in use?

Back 82

Radial flow impellers

Front 83

According to the fire insurance underwriters, no water main should have a diameter less than _____.

Back 83

6 inches

Front 84

A ___________ valve should be installed at dead-end water mains to allow for flushing.

Back 84

Blow-off valve

Front 85

What thrust control device is easy to use, especially in locations where there a lot of existing utilities or structures?

Back 85

Restraining fittings

Front 86

The residual pressure in a large main should be greater than ______ psi during a fire flow event.

Back 86

20

Front 87

The amount of liquid that can be raised vertically by a given pressure is called:

Back 87

Pressure head

Front 88

Pipe cleaning by the air-purging process is used on water mains that are _____ inches in diameter or smaller.

Back 88

4

Front 89

Which is plotted on the horizontal scale (x-axis) of a pump curve?

Back 89

Capacity (flow rate)

Front 90

Identify the type of pipe that can no longer be used for public water supplies.

Back 90

Asbestos cement