Modern Refrigeration and

1
Modern Refrigeration and Air Conditioning
Althouse Turnquist Bracciano
PowerPoint Presentation by Associated Technical
Authors
PublisherThe Goodheart-Willcox Company,
Inc.Tinley Park, Illinois
2
Chapter 2
Refrigeration Tools and Materials
3
Modules

• Tubing and Fittings
• Refrigeration Tools
• Instruments and Gauges
• Supplies and Use

4
Learning Objectives
? List and discuss the various types of tubing
used in refrigeration work.
? Cut and fit tubing using approved methods.
? Demonstrate soldering and brazing techniques.
? Repair cracks and leaks in evaporators.
? Select the proper tools for servicing and
maintaining domestic refrigerators. ? Explain how
to use various hand tools.
5
Learning Objectives

• Discuss the procedures for threading steel pipe.
• Identify thread types.
• Identify different types of threaded fasteners.
• Demonstrate standard procedures for basic
  mechanical service and repair operations.
• Explain how to maintain and calibrate gauges.
• Compare cleaning methods and use of solvents.

6
Learning Objectives

• Explain the use of vacuum and compound gauges.
• Define various types of service valves.
• Discuss the importance of oil in refrigerating
  systems.
• Define purging and explain how it is done.
• Discuss the evacuation of a system.
• Follow approved safety procedures.

7
Chapter 2
TUBING AND FITTINGS MODULE
8
Tubing
2.1.1
ACR tubing is used for refrigeration and air
conditioning.
9
Soft CopperTubing
2.1.1

• Used in domestic and some commercial
  refrigeration and air conditioning.
• Annealed to make it flexible and easy to bend and
  flare.
• Must be supported by clamps or brackets.
• Used with flare fittings and soft soldered
  fittings.
• Can be work-hardened.

10
Hard-DrawnCopper Tubing
2.1.1

• Used in commercial refrigeration and air
  conditioning.
• Hard and stiff.
• Should not be bent.
• Should be brazed.

11
Nominal-SizeCopper Tubing
2.1.1
12
Steel Tubing
2.1.2

• Must be used with refrigerant R-717 (ammonia).
• Connected with flared or brazed joints.

13
Cutting Tubing
2.2.1

• Cut tubing using either a hacksaw or a tube
  cutter.
• Tubing should be straight and cut square (90)
• Remove burrs by reaming.

14
Cutting Tubing
2.2.1
15
Bending Tubing
2.2.1

• Tubing should be bent before installation so that
  no strain is placed on the fittings when
  installed.
• The minimum radius for a tubing bend is between 5
  and 10 times the diameter of the tubing.

16
Bending Tubing
2.2.2
17
Bending Tubing
2.2.1

• Bend tubing gradually.
• A bending spring may be used either inside or
  outside the tubing.

18
Bending Tubing
2.2.2
19
Bending Tubingcontinued
2.2.1

• A gear-type tube bender produces accurate bends.
• A triple-size tube bender can be used for 1/4",
  5/16", and 3/8" OD tubing.

20
Bending Tubing
2.2.2
21
Bending Tubing
2.2.2
22
Flared Connections
2.2.1

• Single-Thickness Flare
• End of tubing must be straight and square with no
  burrs.
• Place the flare nut on the tubing with the open
  end toward the end of the tubing.
• Insert the tube in the flaring tool so that it
  extends above the surface of the block.
• Tighten the clamp so the tube cannot move.

23
Flared Connections

2.2.1
24
Flared Connections

2.2.1
25
Flared Connectionscontinued
2.2.1

• Single-Thickness Flare
• Put a drop of refrigerant oil on the flaring tool
  spinner where it will contact the tubing.
• Tighten the spinner against the tube end one-half
  turn and back it off one-quarter turn. Advance it
  three-quarters turn and again back it off
  one-quarter turn.
• Repeat forward movement and backing off until the
  flare is formed.

26
Flared Connectionscontinued
2.3.1

• Double-Thickness Flare
• Double-thickness flares are recommended only for
  larger-size tubing, 5/16" and over.

27
Flared Connectionscontinued
2.3.1
Simple block and punch tool for forming double
flares on copper tubing.
Tube is clamped in body of flaring block.
28
Flared Connectionscontinued
2.3.1
Simple block and punch tool for forming double
flares on copper tubing.
Female punch bends end of tube inward.
29
Flared Connectionscontinued
2.3.1
Simple block and punch tool for forming double
flares on copper tubing.
Male punch is inserted in partially flared tube.
30
Flared Connectionscontinued
2.3.1
Simple block and punch tool for forming double
flares on copper tubing.
Male punch folds end of tube downward to
form double thickness and expand flare into final
form.
31
SolderedTubing Fittings
2.4.1

• Soldered joints are used for water pipes and
  drains.
• Use if the temperature required to melt the alloy
  used to join copper tubing is below 840F (450C).

32
Soldering Steps
2.4.1

• Cut tube and remove burr.
• Clean outside of tube with abrasive paper or
  cloth.
• Clean inside of fitting with wire brush, abrasive
  paper, or cloth.
• Apply flux thoroughly to outside of tube.

33
Soldering Steps
2.4.1
34
Soldering Stepscontinued
2.4.1

• Assemble tube and fitting.
• Apply heat torch until proper temperature.
• Remove flame and feed solder to the joint. If a
  large-size fitting, tap with a mallet while
  soldering to distribute solder evenly.

35
Soldering Steps
2.4.1
36
Brazing
2.4.2

• Brazing is used if the temperature required to
  flow the alloy is above 840F (450C).
• Used for refrigerant pipes and tubing.
• Produces a stronger bond than soldering.
• Can join similar and dissimilar metals.

37
Brazing Steps
2.4.2

• Degrease parts and clean joints.
• Fit the joints closely and support all parts.
• Apply recommended flux.
• Heat evenly to recommended temperature. Keep
  torch moving constantly in a figure 8 motion.
• Apply brazing alloy to the heated parts.
• Do not heat (melt) brazing alloy with the torch.
• Cool the joint.

38
Brazing Steps
2.4.2
39
Brazingcontinued
2.4.2

• CAUTION
• Acetylene is a highly flammable gas, especially
  when mixed with oxygen.

• Safety glasses should always be worn when
  brazing. Never point the torch (lit or unlit)
  toward an open flame or source of sparks.
• Light the torch only with a sparker do not use
  matches.

40
Brazingcontinued
2.4.2
CAUTION Carefully check the specifications of
the brazing alloy used. If it contains any amount
of cadmium, be certain that the workspace is well
ventilated. Do not breathe any of the fumes. Keep
fumes away from your eyes and skin. Cadmium fumes
are very poisonous. Never use a refrigerant,
oxygen, or compressed air when brazing.
41
Tube Couplings
2.5

• Tube couplings can be used to join aluminum
  tubes to copper tubes. Various methods are
  available, including
• Threaded mechanical fittings.
• Flared fittings.
• Compression fittings.
• Epoxy resin and adhesive kits.

42
Tube Couplings
2.5
43
Pipe Fittings and Sizes
2.8

• Pipe thread sizes are based on flow diameter,
  or approximately the diameter of the hole in
  the pipe (inside diameter, or ID).
• Pipe fittings are supplied with threads already
  cut.

44
Questions

• Which type of copper tubing must be used when
  making flares?

Soft copper tubing.

• Is it possible to use a tube bender on hard-drawn
  copper tubing?

No.

• Which type of tubing must be used on ammonia
  systems?

Steel tubing.

• What is the minimum radius when bending
  refrigerant tubing?

5 to 10 times the diameter of the tubing.
45
Questionscontinued

• When using a spring bender, is it placed on the
  inside or the outside of the copper tubing?

Either the inside or outside.

• Which two tools are used when making a flared
  fitting?

The flaring tool and the flaring block.

• When can soft solder be used in a refrigeration
  system?

Never only on water pipes and drain connections.

46
Questionscontinued

• Which alloy has a melting temperature below 840F
  (450C)?

Soft solder.

• If the required temperature of an alloy is above
  840F (450C), what material must be used?

Brazing material or silver solder.

• When working with refrigerant piping, how are
  sizes determined?

By the outside diameter (OD).
47
Questionscontinued

• When working with plumbing piping, how are sizes
  determined?

By the inside diameter (ID).
48
Chapter 2
REFRIGERATION TOOLS MODULE
49
Wrenches
2.9.1
The types of wrenches most commonly used in
refrigeration and air conditioning installation
and servicing are

• Socket wrenches.
• Box wrenches.
• Open end wrenches.
• Adjustable wrenches.

50
Socket Wrenches

2.9.1
51
Box Wrenches

2.9.1
52
Open End Wrenches

2.9.1
53
Adjustable Wrenches

2.9.1
54
Wrenchescontinued
2.9.1
Always pull on a wrench, rather than push on it.
The sudden loosening of the nut or bolt may cause
a serious hand injury.
55
Wrenchescontinued
2.9.1 and 2.9.2
The fixed end of a service valve wrench is used
to crack the service valve stem. This slight
opening of the valve needle allows a very slow
flow of refrigerant. For rapid opening and
closing of valves, the ratchet end may be used.
56
Hammers
2.9.2

• A ball peen hammer, a carpenters claw hammer,
  and a mallet are useful for the technician.
• Grasp the handle approximately two-thirds of the
  way back from the head.

57
Pliers
2.9.4

• Pliers are universal tools. A variety of pliers
  should be available to the technician.
• Use only pliers with insulated handles when
  working on electrical parts.

58
Screwdrivers
2.95
(Recommended average lengths are 2 1/2", 4", 6",
and 8".)
A complete set of screwdrivers is necessary for
installation and for shop work. The length of a
screwdriver is measured from the blade tip to the
handle.
59
Drills

2.9.7

• Drill designs are available for working metal,
  wood, plastic, and masonry.
• The shank of a twist drill carries a stamped
  identification giving the kind and size of the
  drill.
• Drills are sized by bit diameter.

60
Drillscontinued
2.9.7

• CAUTION
• When using drills, wear safety glasses to protect
  the eyes from flying chips.
• Electric drills should be grounded for safety.

61
Taps
2.9.8

• There are three types of taps available for
  making a hole.
• There are taps for every size or diameter thread
  and for each kind of thread.

62
Taps
2.9.8
63
Tapscontinued

2.9.8

• Dies cut external threads on round stock.
• There are dies for each type of thread and size.

64
Tapscontinued
2.9.8
The tap drill should be slightly larger than the
root diameter of the threads for which the hole
is being drilled.
65
Files

2.9.11

• Files are used for cleaning metal surfaces and
  shaping metal parts.
• They are classified according to tooth size,
  shape, and the number of directions the teeth are
  cut on the file.

66
Hacksaws

2.9.12
Hacksaws are used for cutting tubing and other
metal materials.
67
Questionscontinued

• When using an open-end wrench, how should it be
  used to prevent an injury?

It should be pulled toward you.

• What is the purpose of a tap?

It is used to create a threaded hole in metal
material.

• What is the purpose of a die?

It creates threads on an iron pipe or metal rods.
68
Chapter 2
INSTRUMENTS AND GAUGES MODULE
69
Instrumentsand Gauges
2.10.1
Instruments and gauges are used to determine
conditions (pressure and temperature) inside the
operating mechanism.
70
Thermometers
2.10.1

• Dial stem thermometers are easy to use.
• Their temperature ranges from 40F to 160F
  (40C to 70C).
• A digital thermometer has a temperature range of
  58F to 500F (50C to 260C).

71
Thermometers
2.10.1
72
Pressure Gauges
2.10.2

• Gauge manifolds include both a high-side gauge
  and a low-side (vacuum) gauge.
• They are often color-coded, with the low side
  blue and the high side red.

73
Pressure Gauges

2.10.2
74
Pressure Gaugescontinued
2.10.2

• A high-pressure gauge has a single continuous
  scale, usually marked off to read from 0 psi to
  500 psi.
• It is connected into the high-pressure side of
  the refrigerating mechanism.

75
Pressure Gaugescontinued
2.10.2

• Shown is a two-way digital manifold gauge set
  with LCD readouts.
• The low-side gauge indicates either vacuum or
  pressure reading from 0 to 29.9 inches of mercury
  or 0 to 99.99 psi.
• The high-side gauge reads up through 999 psi.

76
Pressure Gaugescontinued
2.10.2

• A compound gauge measures both pressure and
  vacuum.
• It is usually calibrated from 0 to 30" Hg and
  from 0 psi to 240 psi.

77
Pressure Gaugescontinued

2.10.2
78
Micrometers
2.11.2

• Micrometers are available in both U.S.
  conventional (calibrated in inches and decimals
  of an inch) and SI metric (calibrated in
  millimeters and decimals of a millimeter) units.

79
Micrometers
2.11.2
80
Questionscontinued

• Which thermometer has a greater range, a dial or
  digital type?

A digital type.

• What is the color code of a refrigeration gauge?

Blue is the low side, red is the high side gauge.

• What is the pressure range of the high-side gauge
  that is most commonly used in the field?

0 to 500 psi.

• What is the range of a low-pressure (compound)
  gauge?

From 0 to 30 inches of mercury negative pressure
and from 0 to 240 psi positive pressure.
81
Chapter 2
SUPPLIES AND USE MODULE
82
Machine Screws
2.12.1

• Machine screws are made of steel, stainless
  steel, brass, or other material.

83
Gaskets
2.12.2

• Gaskets are often used between surfaces.
• Metal is the most common gasket material.
• Replacement gaskets must not be thicker than the
  original gaskets.

84
Cleaning Solvents
2.13.3

• Carbon tetrachloride should never be used in
  cleaning refrigeration or air conditioning
  mechanisms. It is toxic and can be absorbed
  through the respiratory system or the skin.

85
Cleaning Solventscontinued
2.13.3

• CAUTION
• Never use gasoline for cleaning. It has a low
  flash point.

86
Refrigerants
2.13.4

• Classified by a cylinder color code.
• Cylinders for different refrigerants must not be
  interchanged.
• Never fill refrigerant cylinders over 80 of
  capacity.
• Do not vent refrigerant directly into the
  atmosphere.

87
Refrigerants
2.13.4
Color codes for the most commonly used
refrigerants.
88
Refrigerant Oil
2.13.5

• The type of oil used must match the type of
  refrigerant used.
• The new azeotropic mixtures and R-134a use polyol
  ester-based oils.
• The traditional refrigerants require mineral oil.
• Use oils with a low pour point to avoid wax
  separation at the lowest temperature in the
  system.

89
Service Valves
2.14

• Enable the technician to seal off parts of the
  system while installing gauges, recharging, or
  discharging the system.
• One-way service valves have only one opening that
  can be opened or closed.
• The two-way service valve has two openings.

90
Service Valves
2.14
91
Vacuum Pump
2.16

• Used to remove vapors, gases, and fluids from a
  refrigerant.
• The pump must run continuously for some time
  while a deep vacuum is drawn on the system.

92
Questionscontinued

• What is the maximum capacity when filling a
  refrigerant cylinder?

It should be filled to no more than 80.

• Which type of oil does R-134a use?

Polyol ester-based oil.

• Traditional refrigerants such as R-12 require
  which type of oil?

Mineral oil.
93
Questionscontinued

• What are two types of service valves used in the
  refrigeration field?

One-way and two-way service valves.

• Which component is used to remove air and
  moisture from a refrigeration system?

A vacuum pump.
94
Safety
2.17

• Files should never be used without handles.
• Wear goggles when drilling. Chips may fly.
• Do not use emery cloth to clean tubing when
  preparing for soldering.
• Never use oxygen to pressure test for leaks.
• Never use carbon tetrachloride for any purpose!
  It is toxic and can be absorbed through the skin.
• Brazing materials may contain cadmium. Fumes from
  heated cadmium are poisonous! Work in a
  well-ventilated space.

95
Safety
2.17

• Refrigerant cylinders should never be filled to
  more than 80 of their capacity.
• Always crack service valves and cylinder valves
  before opening. This gives quick control of the
  flow of gases.
• NEVER purge refrigerant directly to the
  atmosphere.

96
Glossary

• acr tubing
• Tubing used in air conditioning and
  refrigeration. Ends are sealed to keep tubing
  clean and dry.
• annealed
• Metal that has been cooled slowly from a high
  temperature to make it soft.
• azeotropic mixtures
• A liquid mixture having constant maximum and
  minimum boiling points.
• brazing
• Method of joining metals with a nonferrous
  (without iron) filler, using heat between 800F
  (427C) and the melting point of base metals.

97
Glossary

• carbon tetrachloride
• Colorless, nonflammable, and toxic liquid
  previously used as a solvent.
• compound gauge
• Instrument for measuring pressures.
• coupling
• Mechanical device used to join refrigerant lines.

98
Glossary

• flare
• An enlargement at the end of a piece of flexible
  tubing by which the tubing is connected to a
  fitting or another piece of tubing.
• flux
• Substance applied to surfaces to be joined by
  brazing or soldering to keep oxides from forming.
• gaskets
• Resilient (spongy) or flexible material used
  between mating surfaces of parts to give a
  leakproof seal.
• gauge manifolds
• Chamber device constructed to hold both compound
  and high-pressure gauges. Valves control the flow
  of fluids through it.

99
Glossary

• machine screws
• Fine-threaded fasteners manufactured to narrow
  tolerances.
• micrometers
• Precision measuring instruments used for making
  measurements accurate to .001" to .0001".
• nominal-size copper tubing
• Tubing measurement that has an inside diameter
  the same as iron pipe.
• pour point
• Lowest temperature at which a liquid will pour or
  flow.

100
Glossary

• refrigerants
• Substances that absorb heat in evaporator by
  change of state from a liquid to a gas. A
  refrigerant releases its heat in a condenser as
  it returns to a liquid state from the gaseous
  state.
• service valve
• Manually operated valve used for service
  operation on refrigerating systems.
• soldered
• Joining two metals by adhesion of a metal with a
  melting temperature of less than 800F (427C).

101
Glossary

• taps
• Tools used to cut internal threads.
• vacuum pump
• Device used for creating a vacuum for testing or
  drying purposes.
• work-hardened
• Increase in the strength of a material (normally
  a metal) caused by bending and deforming it.