2nd Volume - HVAC/R Fundamentals Flashcards Preview

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Flashcards in 2nd Volume - HVAC/R Fundamentals Deck (132):
1

What is the most common cause of electric shock?

extension cord abuse

2

What are two basic groups of safety directives that apply to the HVAC/R career field?

AFIs and Air Force Occupational Safety and Health (AFOSH) standards

3

What directive states safety policy, sets up mishap prevention program requirements, and assigns responsibilities for program elements?

AFI 91–202, The USAF Mishap Prevention Program

4

Which regulation establishes policy and assigns responsibilities for managing the AFOSH program and applies to all Air Force civilian and military personnel worldwide, including members of the Air National Guard and Air Force Reserve?

AFI 91–301, Air Force Occupational and Environmental Safety, Fire Protection and Health (AFOSH) Program

5

Which regulation prescribes safe practices and procedures for personnel engaged in maintaining and operating electrical systems and facilities?

AFI 32–1064, Electrical Safe Practice.

6

What has the Air Force set up to protect personnel from the harmful effects of hazardous noise?

Hearing Conservation Program

7

A hazardous noise exists if you have to ---BLANK--- to be understood.

shout at 3 feet (a loud voice at 1 foot)

8

When working on circuits over ---BLANK---, workers must not work alone; instead, a safety observer must be present.

300 volts

9

What are the four basic causes of burns?

Thermal, Chemical, Electrical, and Nuclear

10

Which burns are caused by excessive heat?

Thermal

11

What are the three categories of thermal burn damage?

First, Second, and Third Degree

12

Which burn classification is normally associated with sunburns where there’s a reddening of the skin but doesn’t blister or burn through the different layers of skin?

First degree

13

Which burns are characterized by blisters appearing on the first layer of skin?

Second degree

14

Which is the most severe burn a person can get and damages the skin through the top layer and sometimes through the fat that lies beneath it?

Third degree

15

Which burn destroys the nerve endings?

Third degree

16

What happens to the area of a third degree burn?

becomes dry, leathery, and discolored (charred, brown, or white)

17

What are two types of cross connections?

Inlet and Direct (or pressure)

18

What is any actual or potential link or path of flow between a potable water supply and a source of contamination or pollution?

cross connection

19

What type of connection is used to fill a receptacle that’s open to the atmosphere?

Inlet-type connection

20

What is the reversal of the normal water flow in a system?

Back-siphonage

21

What is the reversal of the normal water flow in a system caused by a negative pressure in the supply piping?

Back-siphonage

22

What type of connection is one in which the potable waterline is connected to a nonpotable line or pressurized vessel?

Direct-or pressure-type connection

23

The backflow of ---BLANK--- into a potable water supply would cause a minor change in the water quality

a Class I substance

24

The backflow of ---BLANK--- into a potable water supply could cause illness or death if consumed by humans.

a Class III substance

25

What are the five types of backflow prevention devices?

1. Air gap, 2. Atmospheric-type vacuum breaker, 3. Pressure-type vacuum breaker, 4. Double check valve, 5. Reduced pressure backflow preventer

26

What is a physical separation of the potable and nonpotable system by an air space?

Air Gap

27

For an air gap to work properly, the vertical space between the supply line and the flood-level rim must be at least

two times the inside diameter of the supply pipe and it can’t be less than 1 inch and need not be more than 12 inches

28

Which type of breaker is designed to prevent back-siphonage of Class I substances into a potable water supply?

Atmospheric-type vacuum breaker or Pressure-type vacuum breaker

29

Which type of breaker prevents a vacuum from occurring on the discharge line by allowing air to enter the line?

Atmospheric-type vacuum breaker

30

Which breaker must be installed on the discharge side of the last control valve and above the highest usage point?

Atmospheric-type vacuum breaker

31

Which breaker can’t be used under continuous pressure or be subjected to backpressure?

Atmospheric-type vacuum breaker

32

Which breaker device has a moving, spring-loaded disc float and check valve in the body?

Pressure-type vacuum breaker

33

Which device is used in direct connection-type systems to prevent the backflow of Class I and II substances into the potable water supply?

Double check valve

34

What valve can be used in continuous pressure systems that are subject to backpressure or back-siphonage?

Double check valve

35

Which device has two independently operating, spring-loaded check valves in the body?

Double check valve

36

Which type of backflow preventer may be used on all direct connection-type systems?

reduced pressure backflow preventer

37

What type of backflow preventer is designed to prevent the backflow of all three classes of substances into the potable water supply?

reduced pressure backflow preventer

38

Which backflow preventer is used in continuous pressure systems that are subject to backpressure or backsiphonage?

reduced pressure backflow preventer

39

Which backflow preventer is equipped also with two independently operating spring-loaded check valves, which are located in the body?

reduced pressure backflow preventer

40

Who is responsible for reporting unsafe acts or conditions?

Everyone

41

Which AFI covers areas relating to electrical installations and systems?

32-1064

42

Which AFOSH standard covers areas relating to working around machinery?

91-12

43

Select the statement that best describes your individual responsibility relative to the Air
Force Occupational Safety and Health (AFOSH) program?

Report safety, fire, and health hazards promptly.

44

Leaving tools scattered about is an indication of

Poor housekeeping

45

What types of mishaps must be reported to the safety staff?

All mishaps

46

Select the Air Force program that was established to protect personnel from the harmful effects of hazardous noise.

Hearing Conservation Program.

47

What is the best protection against noise damage?

Isolate systems or pieces of equipment that exceed acceptable noise limits.

48

A safety observer must be present if you are working with a voltage over

300 volts

49

Mechanical equipment that has exposed moving parts must be completely enclosed in a suitable metal guard if the equipment is located above the floor by less than

8 feet

50

When working on rotating equipment, you should avoid

wearing loose clothing

51

Second-degree burns are characterized by

blisters appearing on the first layer of skin

52

When a thermal burn victim has had his or her clothes on fire, and the skin and clothes are still hot, you should immerse them in

cold water for a maximum of 10 minutes

53

Which burn treating statement is correct?

Cover the burned area with a dry, sterile dressing to decrease heat loss

54

What type of cross connection exists if the spout on a sink faucet extends below the overflow rim?

Inlet

55

Which type of backflow preventer is used to prevent back-siphonage of Class I substances and may be used under continuous pressure but not subjected to back-pressure?

Atmospheric-type vacuum breaker.

56

Which type of backflow preventer can be used on all direct connection-type systems to
prevent the backflow of all three classes of substances into the potable water supply?

Reduced pressure backflow preventer.

57

Which backflow preventer is used in continuous pressure systems that are subject to backpressure or backsiphonage?

reduced pressure backflow preventer

58

Which backflow preventer is equipped also with two independently operating spring-loaded check valves, which are located in the body?

reduced pressure backflow preventer

59

The size of a pipe is referred to as

nominal

60

What are the two grades of steel pipe?

1. Standard, or schedule 40, 2. Extra strong (or heavy), or schedule 80

61

What are the most commonly used materials for piping?

Steel, Iron, Copper, and Plastic

62

What is galvanized pipe is coated with?

zinc

63

What is galvanized pipe mostly used for?

domestic water applications

64

What piping does HVAC/R technicians primarily deal with?

black iron piping

65

What are the four most common types of fittings used in HVAC/R systems?

1. Thread, 2. Flange, 3. Flared, 4. Compression Joint

66

What type of fittings are used mostly on steel piping?

Thread and flanges

67

What type of joints are used with copper lines?

Flared and compression

68

How are pipe fittings measured?

by Inside Diameter, not outside diameter

69

What is the main method for joining small diameter pipe?

Threading

70

What limits the threading for various refrigerants and pipe sizes?

ASME Standard B31.5, Refrigeration Piping

71

Pipe with a wall thickness ---BLANK--- than ---BLANK--- should not be threaded.

Less, standard weight

72

What fittings can be used for large pipe and all piping materials?

Flange fittings

73

What fittings are commonly used to connect to equipment, valves, and wherever it may be necessary to open the joint to permit service or replacement of components?

Flange fittings

74

For steel pipe, flanges are available in a pressure rating to ---BLANK---

2,500 psig

75

What three tasks are performed when preparing pipe for fabrication?

1. Measure the pipe, 2. cut the pipe, 3. thread the pipe

76

What fabrication tasks will ensure a minimum of improper or defective connections, and ensure there is a minimum leakage and loss of fluid?

1. Measure the pipe, 2. cut the pipe, 3. thread the pipe

77

What are three methods of measuring pipe?

1. End-to-center, 2. end-to-end, 3. center-to-center

78

Which pipe measurement is taken from the center of an elbow or tee screwed on one end to the opposite end of the pipe?

End-to-center

79

Which pipe measurement is made by first tightening an elbow on the threaded end of a pipe?

End-to-center

80

Which pipe measurement is made without any fittings?

End-to-end

81

What measurements are usually shown on pipe drawings?

Center-to-center

82

Which pipe measurement is the distance between the centers of two fittings in a line of pipe?

Center-to-center

83

What is the first thing you do when making a center-to-center measurement?

put a fitting on the end of the pipe

84

To cut a pipe with a pipe cutter, first open the jaws of the cutter by turning the handle ---BLANK---

Counterclockwise

85

After the wheels contact the pipe on a pipe cutter, rotate the handle ---BLANK---

one-fourth of a turn in a clockwise direction

86

When using a pipe cutter, what puts a "bite" on the pipe causing a groove in the pipe when the cutter is rotated?

rotating the handle one-fourth of a turn in a clockwise direction

87

When using a pipe cutter, what happens if you do not rotate the pipe cutter one turn to make a complete cutting mark around the pipe before turning the handle clockwise to make the cut deeper?

The pipe cutter will make spiral marks around the pipe instead of making on complete circle

88

What happens if you do not remove the burr from a threaded pipe?

The burr hinders the flow of liquids or gases in the pipe

89

What is used to remove a burr from the end of a threaded pipe?

A pipe reamer

90

What are two methods of threading pipe?

Hand and power threading

91

How many threads should be made on pipe with a size of 1/8 inch

27 Threads per inch

92

How many threads should be made on pipe with a size of 1/8 inch

27 Threads per inch

93

How many threads should be made on pipe with a size of 1/4 to 3/8 inch

18 Threads per inch

94

How many threads should be made on pipe with a size of 1/2 to 3/4 inch

14 Threads per inch

95

How many threads should be made on pipe with a size of 1 to 2 inches

11.5 threads per inch

96

How many threads should be made on pipe with a size of 2.5 to 12 inches

8 threads per inch

97

When using a power threader, how far do you insert the pipe into the chuck?

so it protrudes about 8 inches beyond the face of the chuck

98

What are two important factors of pipe fabrication?

1. Assembly of threaded joints, 2. Pipe expansion and flexibility

99

During pipe fabrication, what must be done to attain ample flexibility to accommodate thermal and other movements?

Disigning pipe bends and loops or using supplemental devices such as expansion joints

100

What can happen if you fail to design piping to accommodate thermal and other movements?

1. Failure of pipe and support from over-stress and fatigue, 2. Joint leakage, 3. Detrimental forces and stresses in connected equipment.

101

Copper tubing may be ---BLANK---

Hard drawn or annealed

102

Which copper pipe comes in 20 foot lengths?

hard drawn copper pipe

103

Which tubing is soft-tempered and comes in rolls?

Annealed copper tubing

104

For refrigeration systems, how is tubing size measured?

using outside diameter (OD)

105

What is the difference between plumbing tubing application sizing and refrigeration sizing?

plumbing uses Inside diameter, while refrigeration uses outside diameter

106

How are heating tubing applications sized?

The same as plumbing, using inside diameter (ID) - AKA "nominal-size tubing"

107

What types of tubing are mostly used on waterlines?

nominal-sized tubing - K and L

108

Outside diameter tubing is normally how much bigger than plumbing tubing?

1/8 inch

109

7/8 inch outside diameter (OD) tubing for refrigeration is equal to what Inside Diameter (ID) for plumbing?

3/4 inch

110

What are the three types of copper tubing mostly used in HVAC/R?

1. K, 2. L, and 3. ACR

111

What is used to identify K type copper pipe?

A green-colored band and a stencil on the surface

112

Which copper pipe has the thickest wall?

K type

113

Which copper is mostly hard drawn but can be soft temper?

K type

114

What is used to identify L type copper pipe?

A blue-colored band and a stencil on the surface

115

Which copper is used for recirculating water, refrigerant, and potable water inside buildings?

L Type

116

How can L copper be purchased?

20 feet hard drawn or 25 to 100 feat annealed (soft) coils

117

What is on ACR tubing when it is purchased or new?

Plugs on the ends

118

What do the plugs on the ends of ACR tubing indicate?

That the tubing has been dried and charged with nitrogen from the factory

119

What is the purpose of the plugs (or seals) on the ends of new ACR tubing?

to reduce oxidation within the tube

120

What type of stainless steel tubing is mostly used in the refrigeration trade?

low-carbon, nickel, and chromium stainless steel

121

Why is aluminum being used in refrigeration systems?

because it is lightweight and has a high heat conductivity rating

121

Why is aluminum being used in refrigeration systems?

because it is lightweight and has a high heat conductivity rating

122

What fittings are used when an item needs to be readily replaced or the system needs to be leak-free?

Flare

122

What fittings are used when an item needs to be readily replaced or the system needs to be leak-free?

Flare

123

What fitting is used when you need a permanent connection (or fix)?

Sweat (or solder) fitting

123

What fitting is used when you need a permanent connection (or fix)?

Sweat (or solder) fitting

124

What are the two basic types of tube benders?

1. Bending springs, 2. Lever type

124

What are the two basic types of tube benders?

1. Bending springs, 2. Lever type

125

Which tubing bender can be used when you don't need a high degree of accuracy?

Bending spring

125

Which tubing bender can be used when you don't need a high degree of accuracy?

Bending spring

126

Which tool is used to make tubing bends when a high degree of accuracy is required?

Lever-type bender

126

Which tool is used to make tubing bends when a high degree of accuracy is required?

Lever-type bender