Good Practices in Refrigeration

Good Practices in Refrigeration

Part I TOOLS AND EQUIPMENT
Part II SKILLS AND OPERATION

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Proklima International

Good Practices in Refrigeration

Proklima International

Good Practices in Refrigeration

Published by:

Deutsche Gesellschaft für

Technische Zusammenarbeit (GTZ) GmbH

– German Technical Cooperation –

Programme Proklima

Dag-Hammarskjöld-Weg 1-5

65760 Eschborn, Germany

Internet:

http://www.gtz.de/proklima

Name of sector project:

GTZ Proklima - a programme to save the ozone layer

Contact person at the Federal Ministry for

Economic Cooperation and Development (BMZ):

Gisela Wahlen

German Federal Ministry for Economic Cooperation

and Development (BMZ)

Environment and Sustainable Use of

Natural Resources Division

Bonn, Germany

Email: Gisela.Wahlen@bmz.bund.de

Editors:

Dr. Volkmar Hasse (Programme Manager)

Deutsche Gesellschaft für

Technische Zusammenarbeit (GTZ) GmbH

– German Technical Cooperation –

Programme Proklima

Dag-Hammarskjöld-Weg 1-5

65760 Eschborn, Germany

Email: Volkmar.Hasse@gtz.de

Linda Ederberg and Rebecca Kirch

GTZ Proklima

c/o HEAT GmbH

Zum Talblick 2

61479 Glashütten, Germany

Phone: +49 6174 964575

Email: Linda.Ederberg@proklima.net

Email: Rebecca.Kirch@proklima.net

Technical supervision/responsible for content:

Rolf Hühren

International Consultant

Hohe Straße 23

40213 Duesseldorf, Germany

Phone: +49 211 21073281

Fax: +49 211 56942349

Email: Huehren@aol.com

Design:

Bloomoon – Silke Rabung

Print: Eschborn, March/April 2010

PROKLIMA is a programme of the Deutsche Gesellschaft für Technische

Zusammenarbeit (GTZ) GmbH, commissioned by the German Federal

Ministry for Economic Cooperation and Development (BMZ). PROKLIMA has

been providing technical and financial support for developing countries since

1996 to implement the provisions of the Montreal Protocol on Substances

that Deplete the Ozone Layer.

CONTENT

Good Practices in Refrigeration

Preface .......................................................................1

Part I TOOLS AND EQUIPMENT

Introduction to Part I .................................................. 3

Chapter 1: Tools for Tubing (TT) ............................. 5

Chapter 2: Tools for Refrigerant Handling

and Containment (RHC)......................18

Chapter 3: Equipment for Recovery, Recycling,

Reclamation and Evacuation (RRRE).... 32

Chapter 4: Measuring Instruments (MI) ................. 41

Part II SKILLS AND OPERATION

Introduction to Part II ............................................... 53

Chapter 5: Assembling a Refrigeration System ..... 55

Chapter 6: Bending, the Process .......................... 77

Chapter 7: Brazing, the Process ........................... 81

Chapter 8: Flaring, the Process ............................ 90

Chapter 9: Domestic Refrigeration ....................... 95

Chapter 10: Domestic Refrigeration HC .................104

Chapter 11: Pressing, the Process ..........................121

Chapter 12: Refrigerant, Recovery, Recycling

and Containment in the Field ............ 129

Chapter 13: Retrofit ............................................. 148

Chapter 14: Safety ...............................................164

Annex

Glossary ..................................................................170

Acronyms and Abbreviations ................................... 175

Index ......................................................................176

Acknowledgements

We thank the author Rolf Huehren for his thorough compilation and detailed demonstration of

how to service and maintain refrigeration systems and Daniel Colbourne for technical advice.

Furthermore, we thank the following companies for their kind provision of picture material:

Agramkow Fluid Systems A/S and RTI Technologies Inc., Appion Inc., Peter M. Börsch KG,

Danfoss GmbH, Fluke Deutschland GmbH, GEA Kueba GmbH, Harris Calorific GmbH, IKET –

Institut für Kälte-, Klima- und Energietechnik GmbH, ITE N.V., Ixkes Industrieverpackung e.K.,

Manchester Tank, Mastercool Europe, Moeller GmbH, Ntron Ltd., Panimex, Parker Hannifin GmbH

& Co. KG, Perkeo-Werk GmbH & Co. KG, Refco Manufacturing Ltd., Rotarex, Sanwa Tsusho Co.

Ltd., Georg Schmerler GmbH & Co. KG, Testboy GmbH, Van Steenburgh Engineering Labs Inc.,

Vulkan Lokring Rohrverbindungen GmbH & Co. KG,Worthington Cylinders.

Volkmar Hasse, Linda Ederberg and Rebecca Kirch

Preface

The phase-out of HCFCs and the introduction of various alternative refrigerants confronts both

the servicing technicians and vocational trainers in the refrigeration and air-conditioning sector

with specific problems. Refrigeration technicians are not yet sufficiently prepared to deal with

the new technologies which will have to be introduced in the near future.

The manual ‘GOOD PRACTICES IN REFRIGERATION’ is the second edition of a booklet jointly

published by the PROKLIMA Programme of the ‘Deutsche Gesellschaft für Technische

Zusammenarbeit’ (GTZ) GmbH, the Brazilian ‘Servico Nacional de Aprendizagem Industrial’ (SENAI)

and the ‘Ministério do Meio Ambiente do Brazil’ (MMA) in 2004, which had been widely used as

part of the training courses on ‘Best practices in refrigeration servicing and CFC conservation’,

which were implemented by PROKLIMA as part of the national CFC phase-out plan in Brazil.

This manual has now been updated to provide professional guidance on how to service and

maintain refrigeration systems operating with new technology, e.g. ozone-friendly alternative

refrigerants to CFCs and HCFCs. It addresses essential know-how on containment of HFC refrigerants

which have a high Global Warming Potential (GWP) and are already widely applied. It

also provides extensive information on the safe use of natural refrigerants, such as CO2, Ammonia

or Hydrocarbons, which are much more environmentally-friendly with zero or negligible GWP.These

efficient but still relatively little used refrigerants are in fact suitable replacements for HCFCs in

all applications of refrigeration and air-conditioning equipment.

Part I of this picture book addresses important tools and equipment for tubing; refrigerant handling

and containment; for recovery, recycling, reclamation and evacuation, as well as measuring

instruments. Part II focuses on the handling of servicing and maintenance of refrigeration systems,

such as brazing, flaring, recovery, retrofit and recycling.

Illustrations should help the technicians to easily remember, identify and communicate elements

of best practices in refrigeration.

1

2

Background

Ozone depletion and Montreal Protocol

In the 1970s, scientists discovered the dangerous impact CFCs have in the earth’s atmosphere.

CFCs were used as foam blowing agents, refrigerants and solvents. It was found that they destroy

the ozone layer, so that aggressive UV-B radiation can reach directly the Earth’s surface causing

genetic damage in the cells of people, plants and animals. Therefore, in 1987, an international

treaty was concluded at Montreal, Canada (the so called Montreal Protocol on Substances that

Deplete the Ozone Layer), to prevent the ozone layer from further destruction and begin the phaseout

of the use of CFCs and other ozone-depleting substances (ODS). Until November 2009, all

states worldwide had signed the Protocol.They have worked effectively and successfully towards

a substitution of CFCs which have been banned since1January 2010. In 2007, the treaty was

adjusted to address the phase-out of HCFCs which are the last group of ODS. The refrigeration

and air-conditioning sector, especially in many Article-5 countries, uses very large quantities of

HCFCs and is therefore particularly relevant in the imminent HCFC phase-out.

3

Part I

TOOLS AND EQUIPMENT

INTRODUCTION TO PART I

Part I Tools and Equipment

Introduction to Part I

Proper and environmentally responsible servicing and maintenance of refrigeration

systems requires special equipment, e.g. instruments for refrigerant

leak detection, tools to measure gas pressure and temperature, as well as

special equipment for the general handling and recycling of refrigerants.

The following chapters review various kinds of tools and equipment needed

in modern workshops when working on refrigeration and air-conditioning

systems.

4

Part I

TOOLS AND EQUIPMENT

TOOLS FOR TUBING (TT)

Part I

5

Cuts copper, brass and aluminium tubing

Cutter for 6 to 35 mm tubes diameter

Cutter for 3 to 16 mm tubes diameter

For cutting capillary tubes without collapsing the tubes inside diameter

Cuts all sizes of capillary tubes

Figure 1: Tube cutter (wheel cutter)Figure 2: Capillary tube cutter

Chapter 1: Tools for Tubing

Preface

In the following chapter we will describe tools and equipment for the handling of tubing.

Tools for Tubing

TOOLS AND EQUIPMENT

TOOLS FOR TUBING (TT)

Inner and outer reamer for copper tubing burr removal

Inner-outer reamer for copper tubing

Handy deburrer, blade can be swivelled

Figure 3: Reamer and deburrer

Inner and outer cleaning and finishing with a

Plastic scouring pad

Fitting brush

Figure 4: Scouring pad and brush

TOOLS AND EQUIPMENT

TOOLS FOR TUBING (TT)

Part I

7

Outside cleaning of copper, steel, brass, aluminium tubes

Steel wires

Figure 5: Steel brush

Pinches off copper tubes up to 12 mm diameter

Figure 6: Pinch-off plier

TOOLS AND EQUIPMENT

TOOLS FOR TUBING (TT)

8

Part I

If improperly installed a potential refrigerant leak source!

Not recommended for Hydrocarbon applications!

 Straight solder with tube and service valve 1/4“ male flare SAE Valve core

Figure 7: Extended copper tube with access valve (Schrader)

TOOLS AND EQUIPMENT

TOOLS FOR TUBING (TT)

Assembly of quick coupler from tube to refrigerant hose Clamps directly on straight tubes with diameter from 2 to 10 mm

Same as , but for screwing

Working pressure from 13 mbar to 45 bar

Figure 8: Quick couplers ‘Hansen’

TOOLS AND EQUIPMENT

TOOLS FOR TUBING (TT)

10

 Tool set with fittings, connectors and adapters Straight copper tube press connector

Elbow press connector

Press connector for suction pipe with capillary tube (domestic)

Figure 9: Press system components for tubing

Visual inspection of brazing joints

Figure 10: Telescope inspection mirror

ø6mm

ø6mm

ø2mm

TOOLS AND EQUIPMENT

TOOLS FOR TUBING (TT)

Part I

Faceted flaring bar (holding tool) 6-8-10-12-15 and 16 mm (or inch size)

with flaring cone

Iris-diaphragm flaring bar (holding tool) 5 to 16 mm with flaring cone

Clamp tool with flaring cone

Flaring bars to admit tubes with different diameter

Figure 11: Flaring tool

Swivel handle tube bender for one specific tube size (available from 6 to 18 mm

or inch sizes)

Triple head tube bender for tubes 6, 8 and 10 mm (or inch sizes)

Mechanical tube bender assembly with shoes and counter formers (different sizes)

Figure 12: Tube bender

TOOLS AND EQUIPMENT

TOOLS FOR TUBING (TT)

12

Part I

Tube expander for annealed copper with replaceable

expanding heads (10 to 42 mm or inch sizes)

Example of an expanded copper tube

Expander and headset

Figure 13: Tube expander

TOOLS AND EQUIPMENT

TOOLS FOR TUBING (TT)

Part I

1

Propane/Oxygen brazing unit

Oxygen pressure regulator with hose assembly

Propane (only) brazing unit

Acetylene (only) brazing unit

Acetylene pressure regulator with hose assembly

     Burner (torch)

Figure 14: Brazing equipment

Brazing of copper, brass and aluminium tubing

Torch handle with gas regulators

Twin-flame fork torch

Torch attachments different sizes with tips made of hard copper

Figure 15: Torch (burner) and tips for Propane-Oxygen

TOOLS AND EQUIPMENTTOOLS FOR TUBING (TT)

14

Part I

‘Cigarette’-lighters are dangerous to use

with brazing equipment

Igniter with spark flint (binder form)

Igniter with spark flint and tips cleaner (binder form)

Igniter with spark flint (pistol form)

Figure 16: Lighters

Various design and diameter

Material: brass or copper

Figure 17: Example of fittings

TOOLS AND EQUIPMENT

TOOLS FOR TUBING (TT)

Part I

15

Rod Cu Ag Zn Sn P Melting

Range °C

CP 203 Rest – – – 5.9–6.5 710–890

CP 105 Rest 1.5–2.5 – – 5.9–6.7 645–825

AO 106 35–37 33–35 Rest 2.5–3.5 – 630–730

AO 104 26–28 44–46 Rest 2.5–3.5 – 640–680

AO 203 29–31 43–45 Rest – – 675–735

 Recommended (solder) for copper/copper brazing Recommended (solder) for copper/brass brazing

Figure 18: Brazing rods examples (solder)

Nitrogen cylinder

Nitrogen pressure regulator

Nitrogen transfer hose with 1/4” female flare SAE connection

Figure 19: Nitrogen cylinder

TOOLS AND EQUIPMENT

TOOLS FOR TUBING (TT)

16

Part I

Cylinder various sizes

Cylinder valve with safety valve

Standard guards (tulip shaped)

Standard guard (open-closed shaped)

Figure 20: Cylinder and accessories for technical gases

TOOLS AND EQUIPMENT

TOOLS FOR TUBING (TT)

Part I

17

Powder – 2 kg

Figure 21: Fire extinguisher

TOOLS AND EQUIPMENT

TOOLS FOR REFRIGERANT HANDLING AND CONTAINMENT (RHC)

18

Part I

We have three different pressure gauges!

• The low pressure gauge

• The high pressure gauge

• The vacuum gauge

The pressure gauge body with

transparent removal protection cap

Scale with graduation

Temperature scale (in °F or °C)

Pressure scale (in bar, PSI, kPa…)

Pointer

     Calibration screw

 Refrigerant indication

Brass connection with thread

Figure 1: The pressure gauge

Chapter 2: Tools for Refrigerant Handling andContainment (RHC)

Preface

For the measurements of refrigeration or AC operation pressures and temperatures, for the

purpose of refrigerant transfer and for system evacuation, a service gauge manifold is used.

In the following we would like to describe different gauges and gauge sets and important

tools for refrigerant handling and containment.

The Service Gauge Manifold

TOOLS AND EQUIPMENT

TOOLS FOR REFRIGERANT HANDLING AND CONTAINMENT (RHC)

Part I

19

For easy handling the pressure (low/high) gauges are assembled together with a brass or

aluminium body and valves.

We differentiate 2, 3, 4 and 5-valve service gauge manifold sets.

Support bar

Manifold body

Sight glass for refrigerant flow

Low pressure valve

Vacuum pump valve

     High pressure valve

 Valve connection for

charging cylinder or recovery unit

Hose connection 1/4”male flare SAE

Vacuum hose connection 1/4” and 3/8”

Figure 2: Example of a 4-valve service gauge manifold

Schematic view

of the above 4-valve

service gauge manifold

TOOLS AND EQUIPMENT

TOOLS FOR REFRIGERANT HANDLING AND CONTAINMENT (RHC)

20

Part I

Low pressure gauge for refrigerant HC-R600a Vacuum gauge

Support bar

Valves

Sight glass for refrigerant flow

A perfect service gauge manifold set should have a vacuum gauge

Vacuum gauges are installed regularly at a 4 or 5-valve service gauge manifold

Figure 3: Manifold gauge set for HC refrigerant R600a

TOOLS AND EQUIPMENT

TOOLS FOR REFRIGERANT HANDLING AND CONTAINMENT (RHC)

Part I

21

5-valve service gauge manifold with vacuum gauge

Relative vacuum pressure gauge – measuring range 0 to 1000 mbar

Maximum reading pointer (adjustable)

Calibration screw

Pressure scale

     Absolute vacuum pressure gauge – measuring range 0 to150 mbar

Figure 4: The vacuum gauge

TOOLS AND EQUIPMENTTOOLS FOR REFRIGERANT HANDLING AND CONTAINMENT (RHC)

22

Part I

Refrigerant standard hose with 2 x 1/4” SAE female flare connection

Adjustable and replaceable core-depressor (valve opener) ‘schematic’

Refrigerant hose with inline ball valve, 2 x 1/4” SAE female flare connection

Refrigerant hose with ‘end-mounted’ ball valve for minimal refrigerant emission

Ball valve adapter for standard hose 1/4” SAE male/female connection

     Vacuum hose 2 x 3/8” female flare SAE connection

 Ball valve - 1/4” SAE male x 1/4” SAE female Spare gaskets and core-depressors

Figure 5: Refrigerant transfer hoses and accessories

TOOLS AND EQUIPMENTTOOLS FOR REFRIGERANT HANDLING AND CONTAINMENT (RHC)

Part I

23

Straight coupler for refrigerant hose 1/4” SAE flare male x 1/4” SAE flare female

Elbow coupler for refrigerant hose 1/4” SAE flare male x 1/4” SAE flare female

Core-depressor (valve opener)

Figure 6: Service port quick coupler

Easy and quick core removal without refrigerant emission

Valve

Magnetic core holder

Figure 7: Core removal tools

A B C DTOOLS AND EQUIPMENT

TOOLS FOR REFRIGERANT HANDLING AND CONTAINMENT (RHC)

24

Part I

For removing and replacing valve cores in ‘Schrader’-valves and charging hoses

Tools contain spare valve cores

Figure 8: Core valve removal tool

Enables immediate piercing/access on any refrigerant tubing from 5 to 22 mm

Piercing plier for different diameter/with hand operated valve

Piercing plier/adjustable

Spare needle

Figure 9: Piercing plier (adjustable)

TOOLS AND EQUIPME

TOOLS FOR REFRIGERANT HANDLING AND CONTAINMENT (RHC)

Part I

25

Can valve/extracting of refrigerants out of small disposable refrigerant cylinders

21.8 mm adapter and gasket for connecting a charging hose with 1/4” SAE thread

Stand for liquid charge, disposable cylinder connection to ensure a firm standing

of the cylinder on the charging scale

Figure 11: Charging hose and cylinder connectors

ONLY for temporary system installation

otherwise a potential refrigerant leak source!

Enables piercing/access to any refrigerant tubing from 5 to 16 mm

Figure 10: Piercing valve

TOOLS AND EQUIPMENT

TOOLS FOR REFRIGERANT HANDLING AND CONTAINMENT (RHC)

26

Part I

Low pressure service valve 1/4” male flare x 13 mm quick coupler

Low pressure service quick coupler 14 mm female x 13 mm quick coupler

High pressure service valve 1/4” male flare x 16 mm quick coupler

High pressure service valve quick coupler 14 mm female x 16 mm quick coupler

Figure 12: Automotive (MAC) manual quick service couplers for HFC-134a

TOOLS AND EQUIPMENT

TOOLS FOR REFRIGERANT HANDLING AND CONTAINMENT (RHC)

Part I

27

Refrigerant recovery cylinder DOT standard (US) without OFP (overfill protection)

Liquid level float switch for recovery unit connection (cylinder installation kit)

Refrigerant recovery cylinder DOT standard (US) with OFP (overfill protection)

Refrigerant recovery cylinder EN standard (Europe) according ADR regulation

(Transport of dangerous goods on roads)

Virtual cylinder cut

     Liquid/vapour valve (double valve) with internal safety valve

 Transfer line for gaseous refrigerant

Transfer line for liquid refrigerant (dip-tube)

Figure 13: Refrigerant recovery cylinder

TOOLS AND EQUIPMENT

TOOLS FOR REFRIGERANT HANDLING AND CONTAINMENT (RHC)

28

Part I

Speeds up refrigerant recharge time

Enables efficient refrigerant discharge

Working temperature 55°C/125°F – 300 W capacity

Figure 14: Heating belt with thermostat

‘Checkmate’ test kit for field use

Quick and accurate determination of contaminant levels in oil and refrigerant

Figure 15: Refrigerant and oil contamination test kit

TOOLS AND EQUIPMENT

TOOLS FOR REFRIGERANT HANDLING AND CONTAINMENT (RHC)

Part I

29

The test kit is a single bottle test kit designed to give visual indication as to the acid

content of both mineral and alkylbenzene lubricants. Simply place a sample of oil in the

bottle, shake and look at the colour. If it remains purple, the oil is safe. If it turns orange,

the oil is marginal and steps may need to be taken. If it turns yellow, the oil is acidic and

needs to be changed or other steps need to be taken. Always read the manufacturer’s

instructions before use.

Figure 16: Oil test kit for mineral and alkylbenzene lubricant

The test kit is a single bottle test kit designed to give visual indication as to the acid

content of polyol ester (POE) lubricants. Simply place a sample of oil in the bottle, shake

and look at the colour. If it remains purple, the oil is safe. If it turns orange, the oil is

marginal and steps may need to be taken. If it turns yellow, the oil is acidic and needs to

be changed or other steps need to be taken. Always read the manufacturer’s instructions

before use.

Figure 17: Oil test kit for polyol ester (POE) lubricants

TOOLS AND EQUIPMENT

TOOLS FOR REFRIGERANT HANDLING AND CONTAINMENT (RHC)

30

Part I

The retrofit process requires the removal of mineral based oil and replacement with

polyol ester based lubricants.

When this is required, it is necessary to reduce the mineral based oils to acceptable levels

to assure proper system operation.

The RTK (retrofit test kit) provides a simple method of determining the level of residual

mineral oil in a system. It is ideal for field use as it provides a visual indication of three

levels of mineral oil concentration: Greater than 5%, between 1% and 5% and equal to

or less than 1%. Always read the manufacturer’s instructions before use.

Figure 18: Retrofit test kit

A precise optical instrument that allows the rapid and accurate determination of the

refractive index of liquid solutions. It will specifically assist in determining the percentage

of residual oil remaining in a refrigeration system when converting it to a new refrigeration

oil.

Figure 19: Refractometer

TOOLS AND EQUIPMENT

TOOLS FOR REFRIGERANT HANDLING AND CONTAINMENT (RHC)

Part I

31

Suction connection

Suction hose

Pump outlet with hose connection 1/4“ SAE

Hand pump body

Figure 20: Oil pump

TOOLS AND EQUIPMENT

EQUIPMENT FOR RECOVERY, RECYCLING, RECLAMATION AND EVACUATION (RRRE)

32

Part I

Recovery unit ‘oil less’ for commercial

refrigeration and air-conditioning

Condenser and ventilator

High and low pressure gauges

Refrigerant inlet and outlet valves

Inline filter-drier

     Recovery unit ‘oil based’ for small

commercial,AC and domestic

 Access cord for overfill protection (OFP)

Recovery cylinder

Recovery unit ‘oil less’ for all

refrigerants including CFC-R11

Figure 1: Refrigerant recovery unit

Chapter 3: Equipment for Recovery, Recycling,Reclamation and Evacuation (RRRE)

Preface

The following chapter gives an overview about important equipment used in the field of

recovery, recycling, reclamation and evacuation of refrigeration systems.

Recovery Equipment

TOOLS AND EQUIPMENT

EQUIPMENT FOR RECOVERY, RECYCLING, RECLAMATION AND EVACUATION (RRRE)

Part I

33

Figure 2: Refrigerant recovery and recycling unit

Recovery unit ‘oil less’ for commercial

refrigeration and air-conditioning

equipped with connective facilities

for refrigerant recycling

Refrigerant cleaning module for

recovery unit

Oil separator with oil drainage valve

Filter-drier with sight glass

Recovery unit ‘oil based’ for small

commercial,AC and domestic

     Refrigerant cleaning module for

recovery unit

 Cleaning module for all recovery units

Oil separator with oil drainage valve

Manifold gauge set with high and low

pressure gauges

TOOLS AND EQUIPMENT

EQUIPMENT FOR RECOVERY, RECYCLING, RECLAMATION AND EVACUATION (RRRE)

34

Semiautomatic unit for refrigerantrecycling and MAC application

Dual recycling MAC unit (for two

different refrigerants use)

Internal and external high and low

pressure gauges with hoses and

quick couplers

Internal and external refrigerant

cylinder with OFP and heating device

Automatic refrigerant service station

for MAC, truck and bus

     Automatic refrigerant service station

for MAC

Semiautomatic service unit forMAC, commercial etc.

Figure 3: Recovery, recycling, evacuation and charging unit

TOOLS AND EQUIPMENTEQUIPMENT FOR RECOVERY, RECYCLING, RECLAMATION AND EVACUATION (RRRE)

Part I

35

Refrigerant reclaim machine for high refrigerant processing capacity and purity results

High and low pressure gauges

Control board with refrigerant selector handles up to three different refrigerants

Refrigerant reclaim machine small sized

Figure 4: Refrigerant reclaim machine

Recovery bag for refrigerant CFC-R12 and/or HFC-R134a,

refrigerant capacity up to 250 gr (R12) and 200 gr (R134a),

maximum working temperature 60°C,

maximum overpressure 0.1 bar

Accessories (hose and piercing pliers)

Figure 5: Refrigerant recovery bag

TOOLS AND EQUIPMENTEQUIPMENT FOR RECOVERY, RECYCLING, RECLAMATION AND EVACUATION (RRRE)

36

Part I

Recovery hand pump with handle,maximum overpressure 15 bar, piston

stroke 20/300 mm, output at

frequency with 30 strokes/min and

constant suction pressure of 5 bar

0.14 kg/min vapour and 0.8 kg/min

liquid, weight 1.9 kg, for using with

CFC-R12 and HFC-R134a

Pump body with piston

Inlet pressure suction gauge

In- and outlet port connection

1/4” SAE male

Inline filter-drier size 032

     Refrigerant transfer hose with

ball valve for 1/4” SAE female

Figure 6: Refrigerant recovery hand pump

TOOLS AND EQUIPMENT

EQUIPMENT FOR RECOVERY, RECYCLING, RECLAMATION AND EVACUATION (RRRE)

Part I

37

Double stage vacuum pump 40 L/min (1.44 CFM) to 280 L/min (9.64 CFM),

ultimate vacuum down to 0.16 mbar (12 micron), gas-balast valve equipped

Solenoid valve

Handle with exhaust of purged air

Vacuum gauge (relative)

Oil level sight glass

     Oil mist filter

 3/8” hose connection

Vacuum pump 198 L/min (7 CFM)

Vacuum pump oil container (different sizes)

Figure 7: Vacuum pump

TOOLS AND EQUIPMENTEQUIPMENT FOR RECOVERY, RECYCLING, RECLAMATION AND EVACUATION (RRRE)

38

Part I

 Vacuum pump (double stage) with vacuum gauge Manifold gauge set with high/low pressure gauge

Thermometer for charging cylinder

Charging cylinder with refrigerant scale and graduation

Figure 8: Refrigerant charging and evacuation unit

Vacuum pump (double stage)

Manifold gauge set with R600a / R134a low pressure gauges and vacuum gauge

Electronic charging scale

Refrigerant can support

Figure 9: HC-R600a and HFC-R134a charging and evacuation unit

Charging EquipmentTOOLS AND EQUIPMENT

EQUIPMENT FOR RECOVERY, RECYCLING, RECLAMATION AND EVACUATION (RRRE)

Part I

39

Thermometer or pressure gauge for refrigerant temperature/

pressure indication

Valves for liquid/gas

Transparent scale with refrigerant graduation

Internal refrigerant cylinder

Refrigerant level indication glass pipe

     Charging cylinder stand with refrigerant heater element

Figure 10: Metric refrigerant charging cylinder

HC refrigerant drainage hose (min. 5 m long)

Refrigerant container for HCs 450 gr

Charging hose with adapters and valves

Electronic charging scale

Figure 11: Charging arrangement for HCs

TOOLS AND EQUIPMENT

EQUIPMENT FOR RECOVERY, RECYCLING, RECLAMATION AND EVACUATION (RRRE)

40

Part I

1/4” female SAE connection

Valve

Charging graduation oz/ml

PVC bottle

Figure 12: Compressor lubricant charging/draining cup

Indicates and removes e.g. excess air (NCG) from refrigerant

(CFC-R12 and HFC-R134a) containing cylinders

Figure 13: Non-condensable gases (NCGs) remover

TOOLS AND EQUIPMENT

MEASURING INSTRUMENTS (MI)

Part I

41

Chapter 4: Measuring Instruments (MI)

Preface

The following chapter will describe several instruments for the identification of leaks in

refrigeration systems and different measuring tools for refrigerant charging, electrical values

measurement and compressor capacity test. In addition, we like to present instruments for

refrigerant identification and vacuum control.

Detects all halogenated refrigerants. Points leaks as small as 3 gr per year.

Variable frequency audible alarm. Visual leak indication.

Mechanical pump and flexible metal probe.

Flexible metal probe with sensor

Keypad

Additional spot lighting

Figure 1: Electronic leak detector

Leak Detecting InstrumentsTOOLS AND EQUIPMENT

MEASURING INSTRUMENTS (MI)

42

Part I

Sensitivity less than 50 ppm (Propane, Iso-Butane, Methane) Flexible metal probe with sensor

Keypad

Figure 2: Electronic leak detector for HC refrigerants

Portable halide leak detector kit Propane operated

Propane cylinder, valve and flame head

Sniffle hose

Blue flame (no refrigerant detection)

Green flame (refrigerant detection)

Figure 3: Halide leak detector (banned use in EU)

TOOLS AND EQUIPMENTMEASURING INSTRUMENTS (MI)

Part I

43

Transportable ultra violet (UV) leak detection kit indicates leaks about 3.5 gr per year

for all common refrigerants in AC and refrigeration systems

High intensity UV/blue lamp (100 Watt)

Dye for refrigerant cycle injection

Fluorescence enhancing glasses

Hose with adapter and connections

Injection pump

Figure 4: UV leak detector

Non-corrosive, high viscosity and non-freezing leak detector sprayFigure 5: Leak detection spray

TOOLS AND EQUIPMENT

MEASURING INSTRUMENTS (MI)

44

Part I

Infrared refrigerant identifier determining weight concentration of:

A) CFC-R12, HFC-R134a, HCFC-R22, HCs and air

B) HFC blends, e.g. R404, R407, R410, etc.

LCD display

Inlet filter

Printer

Connection hose with adapter

Figure 6: Refrigerant identifier

Measuring InstrumentsTOOLS AND EQUIPMENT

MEASURING INSTRUMENTS (MI)

Part I

45

Identifier to verify presence and quality of HCFC-R22 refrigerant

Pass / fails indication of 95% pure refrigerant

Confirms the refrigeration system / cylinder content in less than five minutes

Figure 7: Refrigerant identifier for HCFC-R22

Electronic vacuum gauge, measuring range 50 to 5000 microns

Digital vacuum gauge, range 0 to 12,000 microns (different units selectable)

LED display

LCD display

Hose connections

Figure 8: Electronic vacuum gauges (commonly used) examples

TOOLS AND EQUIPMENTMEASURING INSTRUMENTS (MI)

46

Part I

 Electronic charging scale for cylinder and refrigeration systemcharging, capacity 50 kg, accuracy +/–0.5%, resolution 2 gr

Electronic charging scale for small hermetic refrigeration

systems (domestic), capacity up to 5 kg, resolution 1 gr

LCD display

Figure 9: Refrigerant charging scale

Fixture

Graduation for weight

Adjustment kit for maximum filling amount

Feeder hook

Connection cord for overfill protection (OFP)

Figure 10: Spring-type charging scale

TOOLS AND EQUIPMENT

MEASURING INSTRUMENTS (MI)

Part I

47

Electronic thermometer for up to two probes, measuring range –50°C to 1150°C

Electronic thermometer equipped with three probes

Electronic hand thermometer with one probe, measuring range –50°C to 150°C

Refrigerator and freezer thermometer, range –50°C to 50°C

Figure 11: Electronic thermometer

TOOLS AND EQUIPMENTMEASURING INSTRUMENTS (MI)

48

Part I

Noncontact ampere measurement, voltage and resistance measurement

LCD display and holding function for easy reading

Ampere measuring clamp LCD display

Measurement selector Test leads

Figure 12: Digital clamp on meter

Rotating field identification for e.g. scroll-compressors

Rotating field to the right

Connection clamps for three phases

Rotating field (wrong) direction (left)

Figure 13: Rotating field meter

TOOLS AND EQUIPMENTMEASURING INSTRUMENTS (MI)

Part I

49

Tests batteries, capacitors and resistors components

Measurement selector

Test leads

Figure 14: Auto range digital multimeter

Air velocity measurement for AC systems

Vane sensor with integrated thermometer

Measuring device for temperature and air velocity

Figure 15: Anemometer and thermometer

TOOLS AND EQUIPMENTMEASURING INSTRUMENTS (MI)

50

Part I

Measuring of sound level on refrigeration and AC equipment

Measuring range 40 to 140 dB

Sensor

Digital display

Key pad

Figure 16: Sound level meter

Electrical tester, DC Voltage 6 to 220 Volts,AC Voltage 24 to 480 Volts

Mains tester with lead

LED display

Figure 17: Mains tester

TOOLS AND EQUIPMENTMEASURING INSTRUMENTS (MI)

Part I

51

Easy to use tool for testing the compressor’s capacity

Use with dry Nitrogen only!

Quick coupler

Pressure gauge

Adjustable safety valve

Pressure tank

Refrigerant charging hose

Figure 18: Hermetic compressor tester

52Part I

SKILLS AND OPERATION

INTRODUCTION TO PART II

Part II Skills and Operation

Introduction to Part II

Part II provides detailed know-how on professional state-of-the-art service

and maintenance of refrigeration systems, including system assembling and

commissioning. In addition, expertise is provided on skills such as bending,

flaring, brazing and pressing of pipe work needed in the repair of domestic

refrigeration and air-conditioning systems. This is especially important for

systems containing flammable Hydrocarbon refrigerants which have to be

treated with extra care.

Part II

53

54

Part II

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

Part II

55

Figure 1: Soft and hard copper comparison

Chapter 5: Assembling a Refrigeration System

Preface

Beside the installation of the main refrigeration system components, the refrigerant pipe

work has to be carried out in a perfect clean and proper manner.

The most common pipe work you will find on refrigeration systems is made of copper. It is

sized by the actual outside diameter and comes in lengths of 5 to 6 m (16 to 20 feet) in

hard copper and coils of 15 to 50 m (50 to 165 feet) in soft copper.

There are two common types of copper piping:

• Hard Copper (rigid copper)

• Soft Copper (annealed copper)

Specially designed and prepared copper pipes are used in refrigeration as they can be used

for higher pressures. They arrive from the producer sealed at both ends to prevent contamination

by moisture or dust etc ...

Soft Copper

Soft, flexible copper tube is really more versatile than a rigid copper pipe. It comes in much

longer lengths which are rolled and requires fewer joints which reduce leak potential. Due

to its fairly flexible nature it can be positioned and shaped easily which saves time.

Hard Copper

Hard Copper piping is rigid and is identified by size and name. This type of piping makes a

neater installation, but it is more time consuming and difficult to install than soft tubing. It

needs very little mechanical support to keep it in position, compared to soft copper.

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

56

Part II

The table below shows common pipe sizes:

European Standard

Copper Coils (annealed) Copper Coils (annealed)

INCH METRIC

Diameter Length (m) Wall (mm) Diameter Length (m) Wall (mm)

3/16” 50 1 4 mm 25 1

1/4” 30 1 6 mm 25 1

5/16” 50 1 8 mm 25 1

3/8” 30 1 10 mm 25 1

1/2” 30 1 12 mm 25 1

5/8” 30 1 15 mm 25 1

3/4” 15 1 16 mm 25 1

7/8” 15 1 18 mm 25 1

22 mm 25 1

Table 1: Soft copper (annealed) European standard

US Standard

Copper Coils (annealed)

INCH

Diameter Length (Ft) Wall (mm)

1/8” 50 0.76

3/16” 50 0.76

1/4” 50 0.76

5/16” 50 0.81

3/8” 50 0.81

1/2” 50 0.81

5/8” 50 0.89

3/4” 50 0.89

7/8” 50 1.14

11/8” 50 1.21

13/8” 50 1.40

15/8” 50 1.52

Table 2: Soft copper (annealed) US standard

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

Part II

57

European Standard

Rigid Copper Straight Length Rigid Copper Straight Length

INCH METRIC

Diameter Length (m) Wall (mm) Diameter Length (m) Wall (mm)

1/4” 4 or 5 1 6 mm 5 1

3/8” 4 or 5 1 8 mm 5 1

1/2” 4 or 5 1 10 mm 5 1

5/8” 4 or 5 1 12 mm 5 1

3/4” 4 or 5 1 15 mm 5 1

7/8” 4 or 5 1 16 mm 5 1

1” 4 or 5 1 18 mm 5 1

11/8” 4 or 5 1 22 mm 5 1

13/8” 4 or 5 1.24 28 mm 5 1.5

15/8” 4 or 5 1.24 35 mm 5 1.5

21/8” 4 or 5 1.65 42 mm 5 1.5

25/8” 4 or 5 2.10 54 mm 5 2

31/8” 4 or 5 2.50 64 mm 5 2

35/8” 4 2.50 76 mm 5 2

41/8” 4 2.50 89 mm 5 2

108 mm 5 2.5

Table 3: Rigid copper (hard) European standard - inch/metric

US Standard

Rigid Copper Straight Length

INCH

Diameter Length (Ft) Wall (mm) Diameter Length (Ft) Wall (mm)

3/8” 16.4 0.76 15/8” 16.4 1.53

1/2” 16.4 0.89 21/8” 16.4 1.78

5/8” 16.4 1.02 25/8” 16.4 2.03

3/4” 16.4 1.07 31/8” 16.4 2.29

7/8” 16.4 1.14 35/8” 16.4 2.54

11/8” 16.4 1.21 41/8” 16.4 2.79

13/8” 16.4 1.40

Table 4: Rigid copper (hard) US standard

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

58

Part II

The refrigeration capacity of the system is influenced by pressure drops in the pipe work.

Such pressure loss not only results in a decrease in cooling capacity but also in an increase

in the compressor’s power consumption.

Sizing of the piping system is determined by the following factors:

• Pressure drops

• Flow velocity

• Oil return

For the assembling of the selected refrigeration system (demo unit) the following pipe

diameters are selected:

• Suction pipe 10 mm

• Liquid pipe 6 mm

Dimensions/

Item Qty. Unity Part Reference Range

1 1 Piece Hermetic DANFOSS SC 15 GXT2 HxWxD/mm

condensing unit Refrigerant HFC-R134a 296x333x451

Ref. capacity –5°C/830W Weight 21.6 kg

Power input 600W

230V/1Ph/50Hz

2 1 Piece Evaporator KUEBA DFA 031 HxWxD/mm

Refrigerant HFC-R134a 165x580x510

Ref. capacity –5°C/900W Weight 10 kg

Surface 4.9 m2

Fan 230V/1Ph/50Hz/29W

3 1 Piece Th.expansion DANFOSS TN 2 3/8” Inlet

valve 1/2” Outlet

4 1 Piece Th. expansion DANFOSS

valve with inlet Size 01

strainer

5 1 Piece Filter-drier DANFOSS 6 mm/ 1/4” flared male

DML x 6 mm/1/4” flared male

6 1 Piece Sight glass DANFOSS 6 mm/ 1/4” flared male

SGN x 6 mm/1/4” flared female

7 1 Piece Solenoid valve DANFOSS 6 mm/1/4” flared male

EVR 3 x 6 mm/1/4” flared male

8 1 Piece Capillary tube DANFOSS Temperature range

thermostat KP 62 – 40°C to +65°C

System Design and Selection Criteria

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

Part II

59

Dimensions/

Item Qty. Unity Part Reference Range

9 1 Piece Dual pressure DANFOSS LP – 0.7 to 4 bar

switch KP15 HP – 8 to 32 bar

10 5 m Soft copper pipe Liquid pipe 6 x 1 mm/1/4”

11 5 m Soft copper pipe Suction pipe 10 x 1 mm/3/8”

12 3 Piece Brass union 10 mm/3/8”

coupling 5/8” UNF

13 6 Piece Brass SAE nut 10 mm/ 3/8”

for union coupling 5/8” UNF

14 1 Piece Brass SAE nut 1/2”/10 mm hole

Expansion valve outlet 3/4” UNF

15 1 Piece Brass SAE Nut 3/8”/6 mm hole

Expansion valve inlet 5/8” UNF

16 2 Piece Brass SAE nut/ 1/4”/6 mm hole

filter-drier and 7/16” UNF

sight glass

17 2 Piece Brass SAE nut/ 1/4”/6 mm hole

solenoid valve 7/16” UNF

18 1 Piece Forged brass 3/8” Pipe – 7/16” UNF

tee with valve

core/evaporator

measurements

19 1 Piece Master switch MOELLER – SVB 230V/1Ph/50Hz

with housing

20 1 Piece Indicator light green 230V/1Ph/50Hz

21 1 Piece Indicator light red 230V/1Ph/50Hz

22 1 Piece Cable HENSEL D9045 98x98x58 mm

connection box 5 Openings

23 6 m Electrical cable

flexible 3 x 1.5 mm2

24 40 Piece Cable fastener

25 10 Piece Copper pipe clips 6 mm/1/4”

26 10 Piece Copper pipe clips 10 mm/ 3/8”

27 1 Piece Perforated plate 500 x 800 mm

(metal)

28 50 Piece Sheet screws

29 8 m Hollow punch 36 x 36 mm

30 2 Piece Floor stands 36 x 36 mm

31 4 Piece Angel 45°

32 2 Piece Frame angel 90°

33 18 Piece Screw set M8 x 40 mm

frame

Table 5: Complete list of material (parts as selected or similar)

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

60

Part II

Hermetic compressor

Discharge pipe

Refrigerant condenser

Refrigerant receiver

Service connection

Shut-off valve

Refrigerant liquid pipe

     Filter-drier

 Refrigerant sight glass

Solenoid valve

Thermostatic expansion valve

Capillary tube with sensor

Refrigerant evaporator

Service connection

Suction pipe

Shut-off valve

Service connection

Figure 2: The refrigeration system layout (refrigerant flow schematic)

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

Part II

61

230V/1Ph/50Hz

L Electr. connection ‘phase’

N Electr. connection ‘neutral wire’

S1 Main switch (on-off)

TC Thermostat

Y1 Solenoid valve

LP Low pressure switch

HP High pressure cut-off

M1 Condenser fan motor

M2 Evaporator fan motor

OP Overload protection (compressor)

RW Running winding (compressor)

SW Start winding (compressor)

M3 Refrigerant compressor

SR Start relay

UR Unload resistor (C1)

C1 Start capacitor

C2 Running capacitor

H1 Indicator light ‘operation’ green

H2 Indicator light ‘high pressure’ red

Figure 3: The electrical wiring diagram (pump-out/pump-down)

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

62

Part II

Figure 4: Condensing unit

Figure 5: Evaporator

Figure 6: Evaporator air circulation (schematic)

Condensing unit

Hermetic

Refrigerant HFC-R134a

Voltage 230V/1Ph/50Hz

Refrigeration capacity 875W

to –5°C/amb.temp. 32°C

Maximal amb.temp 43°C

Evaporator

Air forced

Refrigerant HFC-R134a

Voltage 230V/1Ph/50Hz

Refrigeration capacity 950W

to –5°C

1 Ventilator/29W

Surface 4.9 m3

Lamella spacing 4.2 mm

Main Components for System Assembling

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

Part II

63

Figure 7: Thermostatic expansion valve

Figure 8: Solenoid valve

Figure 9: Filter-drier

Thermostatic

expansion valve

with internal equalization

Refrigerant HFC-R134a

flare/flare connection

inlet size 1/4” (6 mm),

outlet 1/2” (12 mm)

Solenoid valve

Normally closed (NC)

Refrigerants: CFC, HCFC, HFC

Inlet/Outlet 1/4”/6 mm

Min. opening differential

pressure 0.0 bar

Brazing or flaring connections

Filter-drier

Optimized for HFC refrigerant

Brazing or flaring connections

Inlet/Outlet 1/4”/6 mm SAE

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

64

Part II

Figure 10: Sight glass

Figure 11: Thermostat

Figure 12: Dual pressure switch

Sight glass

with colour indicator for

moisture content in refrigerant

Ambient temperature:

–50°C to +80°C

Max. working pressure: 35 bar

Inlet/Outlet 1/4”/6 mm SAE

Thermostat

with capillary tube

Ambient temperature:

–40 to +65°C

Dual pressure switch

LP – 0.7 to 4 bar

HP – 8 to 32 bar

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

Part II

65

Figure 13: Master switch (photo courtesy of Moeller GmbH)

Master switch

with Housing

230V/1Ph/50Hz

Figure 14: Refrigeration system (front view)

Front view of the

refrigeration system

• Cut hollow punch and

assemble frame

• Install stand and angle

• Place evaporator

• Place condensing unit

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

66

Part II

Rear view of the

refrigeration system

• Evaporator section

• Install perforated metal plate

Figure 16: Evaporator in detail

Detail evaporator

• Expansion valve with nozzle

installation

• Inserted nozzle and fix flare-nut

• Temperature sensor with

capillary tube

• Brass tee with valve core

connection at suction line

(outlet evaporator)

Figure 15: Refrigeration system (rear view)

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

Part II

67

Figure 17: Dual pressure switch in detail

Install dual pressure

switch for high and

low pressure control

• Dual pressure switch

Figure 18: Refrigerant circuit components

Install refrigerant

circuit components

including piping

• Solenoid valve

• Flare-nut (example)

• Sight glass

• Filter-drier

Bending

of copper

tubes

Brazing

Flaring

References

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

68

Part II

References

Figure 19: Electrical components

Install electrical

components

• Thermostat

• Master switch

• Cable connection box

• Install and fix electric cable

Figure 20: Pipe work installation

Install remaining

pipe work

• Suction line

• Liquid line

• Process pipes for

dual pressure switch

Bending

of copper

tubes

Brazing

Flaring

Tools RHC

Page 23

Figure

6+7

References

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

Part II

69

The operational reliability and service life of a refrigeration system primarily depends on the

degree of contamination, the moisture and non-condensable gases (e.g. air) contained in

the refrigeration cycle and the hermetic design and construction (leak tightness).

Improved hermetisation of the refrigeration cycles enables a reduction of substances entering

and escaping from the system during operation. All these facts and backgrounds enable

the operation in an environmentally protective and energy-efficient manner.

The previously assembled refrigeration system provides for system commissioning several

service connections. These service connections are located as follows:

Service port at liquid line

(outlet receiver)

Service port at suction

line (inlet compressor)

Service port at the

evaporator

Service port

suction line

Service port

liquid line

Figure 21: Service connections overview

Figure 22: Service connections in detail

A

A

B

B

Commissioning

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

70

Part II

This leak test provides information on the overall leak tightness of the refrigerated system.

Only dry Nitrogen must be introduced into the refrigerated system.

Transferring the dry Nitrogen gas from both, the high and low pressure side up to a system

pressure of a maximum of 10 bar.

NEVER USE OXYGEN (e.g. shop-air) FOR PRESSURIZING A REFRIGERATION SYSTEM.

Connect the Nitrogen

cylinder’s pressure

regulator to the manifold

gauge set centre port.

Connect the high pressure

gauge to the system’s high

side service port.

Connect the low pressure

gauge to the system’s low

side service port.

Figure 23: Pressure leak test

References

MI

Page 43

Figure 5

Tools RHC

Page 18

to 22

TT

Page 15

Figure 19

Pressure Leak Test

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

Part II

71

Most importantly, the evacuation of a refrigeration system is a matter of reducing the content

of non-condensable gases such as air and Nitrogen. Additionally, introduced humidity during

the assembling process must be removed before system operation.

The pressure measured finally with the vacuum process should be about 0.5 mbar (50 Pa,

375 micron) or better.

If possible, a system should be evacuated on both, high and low pressure sides. To be able

to ensure the specified vacuum, it is therefore necessary (if possible) to measure the pressure

with a vacuum gauge in the system and not directly at the vacuum pump.

Short hoses with large diameter (e.g. 3/8”) are best for evacuating and greatly reduce the

time required for evacuation. Most manufacturers recommend evacuating down to at least

250 microns.You may even come across specifications requiring a 50 micron evacuation.To

achieve vacuums that are so low, you would have to use large diameter and very short connections

between the vacuum pump and the system. Standard flexible hoses (1/4”) just don’t

seal enough and also present too much restriction flow to achieve those types of vacuum.

• Pressurize the refrigeration system up to a

maximum of 10 bar dry Nitrogen.

• Close the pressure regulator and hold the

pressure in the system.

• Observe the pressure at gauges. If leaks exist,

pressure will drop. Some leaks are audible and

can be identified by the sound of discharging gas.

• Check all connections, flares and joints with

soap water solution. Identify leaks by bubbles

formed by discharging Nitrogen.

• Repair leaks.

• If necessary repeat leak test.

Figure 23a: Example of a leaky connection (see bubbles)

Evacuation

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

72

Part II

Connect the vacuum

gauge to the service port

at the evaporator’s outlet

service port.

Run the vacuum pump and

read the vacuum indicated

at the vacuum gauge. Figure 24: Evacuation

of a refrigeration system

References

The compressor must never be operated without refrigerant or under vacuum. A damage

of the compressor would result.

If the filling capacity of the plant is known, liquid charging of the refrigerant into the

high side of the system can be carried out with the plant at rest, against vacuum, using a

charging cylinder or scales.

Connect the vacuum

pump to the manifold

gauge set to the centre

port.

RRRE

Page 37

Figure 7

MI

Page 45

Figure 8

Charging

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

Part II

73

Connect the refrigerant

charging cylinder on

scale to the manifold

gauge centre port.

Purge the air out of

the charging hose.

Figure 25: Charging of a refrigerant system

Be extremely careful when charging liquid refrigerant to the low side of the system. Liquid

(in large amounts) must never enter the compressor. For this reason prevent the compressor

from the so called ‘liquid hammer’ while charging refrigerant. R134a is a single substance

refrigerant and may therefore be charged into the system from the refrigerant cylinder in

vapour or liquid form.

If the charging amount is yet to be determined, first fill in refrigerant until the low pressure

switch responds and the compressor can be started. In general, it is sufficient to charge half

of the rated quantity to be able to operate the compressor during the charging operation

without compressor damage. Measure the charged amount of refrigerant.

MI

Page 46

Figure 9

References

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

74

Part II

After the charging process the adjustment and functioning of the safety devices and other

control devices must be checked. The system must be operated until sufficient system conditions

are visible. Meanwhile temperature and pressure values should be recorded and the

system must receive a label showing actual figures e.g. type and amount of refrigerant

charged. After disconnection of gauges and hoses a final leak test has to be performed.

Once again use soap water and/or an electronic leak-detector and you will find that there

are common places to check. The following lists some very common leak locations:

• Flare-nuts

• Service valve: packing, access fitting, mounting

• Cracked brazed joint in piping

• Rotted evaporator end bends

• Pipes rubbing together

• Cracked ferrous brazed in accessory

Figure 26: Overview of a refrigerant system

References

MI

Page 41

Figure 1

Page 42

Figure 2

System Check and Final Leak Test

MI Page 47-Figure 11, Page 48-Figure 12, Page 50-Figure 17

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

Part II

75

Figure 27: Measuring spots for temperature and pressure

References

P1

T2

T1

T11

T10 P3

T8

T9

T4

T3 T5

P2

T7

T6

SKILLS AND OPERATION

ASSEMBLING A REFRIGERATION SYSTEM

76

Part II

Table 6: Start-up data sheet

Start-Up Data Sheet

Technician name

Address

Telephone & fax no.

Registration no.

Installation/Appliance DATA

Type of installation Model and no.

Date started Date finished

Operating Data

Refrigerant type Refrigerant charge

Type of lubricant Lubricant charge

Suction pressure P1 Condensing pressure P2

Suction pressure evap. P3

Discharge temp. T1 Hotgas temp. T2

Air temp. ent. cond. T3 Air temp. leav. cond. T4

Temp. ref. leav. cond. T5 Temp. liquid ent. filter T6

Temp. ref. leav. filter T7 Air temp. ent. evap. T8

Air temp. leav. evap. T9 Temp. gas leav. evap. T10

Temp. gas ent. comp. T11

LP-switch cut-off HP-switch cut-off

Electrical Data

Power supply (voltage) L1 L2 L3

Overall ampere reading L1 L2 L3

Current draw compressor L1 L2 L3

Current draw fan evapor.

Current draw fan cond.

Other Installation Data

Discharge line diameter Discharge line length

Liquid line diameter Liquid line length

Suction line diameter Suction line length

Insulation suction line Altitude diff. compr./evap.

Type of condenser Type of evaporator

Type of filter-drier Type and size of receiver

Remarks:

Signature technician

Date

Always follow specific safety regulations!

(see also chapter safety)

SKILLS AND OPERATION

BENDING, THE PROCESS

Part II

77

Chapter 6: Bending, the Process

Preface

Because of its exceptional formability, copper can be formed as desired at the job site.

Copper tube, properly bent, will not collapse on the outside of the bend and will not buckle

on the inside of the bend.

Because copper is readily formed, expansion loops and other bends necessary in an assembly

are quickly and simply made if the proper method and equipment are used.

Simple hand tools employing mandrels, dies, forms and fillers, or power-operated bending

machines can be used.

Both annealed tube and hard drawn tube can be bent with the appropriate benders. The

proper size of bender for each tube size must be used.

Portable bending machines, suitable for bending tubes up to and including 54 mm outside

diameter (OD) are available, indeed some smaller benders up to 22 mm can be carried in

a tool kit. For tube sizes larger than 54 mm, fixed power benders are the only satisfactory

option. All bending machines work on the principle that the tubing is bent between

matched formers and back guides, which support the OD of the tubing, thus eliminating

the risk of collapse of the tube wall.

SKILLS AND OPERATION

BENDING, THE PROCESS

78

Part II

TT

Page 11

Figure 12

Only the use of sealed and

interiorly clean and dry copper

tubes is permitted.

This bad example shows

an inappropriately treated

and stored copper tube.

Collapsed tube

No seal plug for tube inside

protection.

Positioning

The bending tool diameter must

match the copper tube diameter.

With the handles at 180° and

the tube holding clip raised out

of the way, insert the tube in the

forming wheel groove.

Bending start position

Place the tube-holding clip over

the tube and bring the handle

into an approximately right angle

position, engaging the forming

shoe over the tube.

The zero mark on the forming

wheel should then be even with

the front edge of the forming shoe.

References

Figure 1: Inappropriately

treated copper tube

Figure 2: Tube-holding

Figure 3: Tube-holding position

TT

Page 11

Figure 12

Bending Process Steps

SKILLS AND OPERATION

BENDING, THE PROCESS

Part II

79

Bending the tube

Bend by pulling the handles

towards each other in a

smooth, continuous motion.

The desired angle of the

bend will be indicated by the

calibrations on the forming

wheel.

Tool removal

Remove the bent tube by

pivoting the handle to a

right angle with the tube,

disengaging the forming

shoe.

Then release the tubeholding

clip.

Bending copper

and tool example

References

Figure 4: Bending of the tube

Figure 5: Removing of the bent tube

Figure 6: Bending process

TT

Page 11

Figure

12 (1)

TT

Page 11

Figure 12

TT

Page 11

Figure 12

SKILLS AND OPERATION

BENDING, THE PROCESS

80

Part II

Bending copper

and tool example

Bending copper

and tool example

Figure 7: Example of bent copper

Figure 8: Bending copper tool

References

TT

Page 11

Figure

12 (2)

TT

Page 11

Figure

12 (3)

Piping should be designed to use a minimum number of bends and fittings. It is most important

to minimize pressure drop in the suction line so plan your piping layout around the

optimum route for the suction line.

If you are manually bending some soft copper and you accidentally kink the pipe, cut out

and discard the kinked section and try again. It is much easier to correct the problem now

than it is after the system is in operation. There is no excuse for allowing unnecessary pressure

drop to affect a system for its entire operational life.

SKILLS AND OPERATION

BRAZING, THE PROCESS

Part II

81

Chapter 7: Brazing, the Process

Preface

Brazing and soldering techniques are the most common methods of joining copper tubes

and fittings.

Since modern technologies and best practices have been introduced and regulations have

been developed for the sectors of refrigeration and air-conditioning, the only technical

standard in this field is BRAZING.

Good brazing joints are strong, durable and stay tight! Brazing is necessary to provide joints

that can withstand vibration, temperature and thermal cycling stress.

The basic theory and techniques of soldering and brazing are the same for all diameters of

copper tubes. The only variables are the filler metal and the amount of time and heat required

to complete a given joint.

Soldering is the joining process that takes place below 450°C (840°F) and brazing as a

process that takes place above 450°C (840°F), but below the melting point of the base

metals. Most brazing is done at temperatures ranging from 600°C to 815°C (1100°F to

1500°F).

Brazing carried out while using copper-phosphorus (CP) filler metals is the preferred method

for making non-detachable joints. No flux is needed as the vaporised phosphorus will remove

the copper oxide film. Flux used for brazing may also contaminate the environment inside

tubing and must be removed after the brazing process. Nitrogen introduction as protective

gas (very low flow rate inside the pipe assembly during brazing process)

is a common method to avoid oxidation.

Purging refrigerant pipelines whilst brazing with dry Nitrogen.

When heat is applied to copper in the presence of air (oxygen), oxides form on the surfaces of

the tube. This is very harmful for a durable functioning of the refrigeration system in general

but primarily for the compressor’s lubricating system. Oxide scale on the inside of refrigerant

pipelines can lead to problems once the refrigerant and the lubricant is circulating in

the system. Refrigerants have a scouring effect that will lift the scale from the tubing and

this can be carried through the system and lead to form sludge.

The formation of oxides when brazing can be easily prevented: this is achieved by slowly

passing Nitrogen through the pipework whilst the heat is being applied.

Always follow specific safety regulations!

(see also chapter safety)

SKILLS AND OPERATION

BRAZING, THE PROCESS

82

Part II

The previously mentioned brazing techniques are approved and accepted standards for

brazing in the refrigeration and air-conditioning sector.

Basic steps for brazing and joining copper tubes and fittings:

1. Measuring and cutting

2. Reaming

3. Cleaning

4. Assembly and support

5. Nitrogen introduction

6. Heating

7. Applying the filler metal

8. Cooling and cleaning

SKILLS AND OPERATION

BRAZING, THE PROCESS

Part II

83

Cutting tube

Use a wheel cutter rather

than a hacksaw in order to

prevent swarf entering the

tube.

Removing internal

burrs

A deburrer, reamer or round

file can be used to remove

internal burrs.

Prevent the entering of

swarfs into the tube and

fitting arrangement.

References

Figure 1: Cutting tube

Figure 2: Removing of burrs

Figure 3: Further processing with file

TT

Page 6

Figure 3

TT

Page 5

Figure 1

Brazing Process Steps

SKILLS AND OPERATION

BRAZING, THE PROCESS

84

Part II

Cleaning the surfaces

For surface cleaning use a

abrasive plastic scouring pad.

Prevent cleaning particles

or swarf from entering the tube.

Cleaning the fitting

For interior fitting cleaning

use a properly sized fitting

brush.

Assembly

Put the pipe and fitting or

expanded pipes together and

make sure you maintain the

right joint depth.

References

Figure 5: Fitting cleaning with brush

Figure 6: Assembly of pipe and fitting

TT

Page 6

Figure 4

(2)

TT

Page 6

Figure 4

Figure 4: Cleaning of surfaces

SKILLS AND OPERATION

BRAZING, THE PROCESS

Part II

85

TT

Page 13

Figure 15

Page 14

Figure16

Purge tubes

Purge residues out of the tubes before brazing. Use dry Nitrogen for purging.

Apply Nitrogen flow

Prevent oxide formation on the

inner surface of the tubes.

Once the refrigerant is circulating

in the system, oxide scale on the

inside of the tubes can lead to

serious problems.

Slowly pass Nitrogen through

the pipework, the far end of

the pipework to be open to the

atmosphere, without building

up a pressure.

Flow rate should be about 1 to 2

liter per minute. Flow rate sensitively

can be felt easily on the

back of a moistened hand.

References

Figure 7: Application of Nitrogen flow

Figure 8: Torch adjustment

TT

Page 15

Figure 19

TT

Page 15

Figure 19

Torch (flame) adjustment

Adjust the torch for a slightly

reduced flame.

Blue flame

Green ‘feather’

Light torch flame only

with safe lighters!

Nitrogen transfer hose

SKILLS AND OPERATION

BRAZING, THE PROCESS

86

Part II

Apply heat

Apply heat uniformly to both,

tube and fitting, by moving

the torch around to ensure even

heating before adding the filler

material (rod).

Apply filler

As the heated area gradually

changes colour to red (a cherry

red but not a bright red),

apply filler material (rod) by

lightly brushing the tip of the

stick into the shoulder of the

fitting.

Care should be taken not to

over-heat the tube!

Complete joint

To complete the joint, an even

build-up of solder should

be just visible arround the

shoulder of the fitting.

Filler (rod)

References

Figure 10: Filler application

Figure 11: Filler in detail

TT

Page 15

Figure 18

Figure 9: Heat application

SKILLS AND OPERATION

BRAZING, THE PROCESS

Part II

87

Remove the heat

Remove the heat until the

molten brazing alloy solidifies

to a tan black colour (approx.

10 to 15 seconds).

Finnish brazing

After brazing is completed, the joints are normally left to cool in the air.

Stop the flow of Nitrogen.

However, if necessary, the joint may be cooled with a wet rag.

Brass to copper tube brazing

This combination of materials

requires the use of e.g. a water

solble flux. Apply a small amount

of flux to the end of the tube

and to the inside surface of the

fitting. Avoid spilling of flux

inside the tube and fitting, as

the residue needs to be removed

on completion.

References

Figure 13: Flux application

Figure 12: Heat removal

SKILLS AND OPERATION

BRAZING, THE PROCESS

88

Part II

The procedure for these joints is

essentially the same as for copper

to copper brazing, only that more

heat should initially be concentrated

on the brass fitting to

bring it to temperature.

Take care not to overheat the fitting.

Dull red colour is sufficient.

Use brazing rods with higher

content of silver (Ag).

References

Figure 14: Brass adapter

TT

Page 15

Figure 18

Figure 15: Brass adapter brazing

SKILLS AND OPERATION

BRAZING, THE PROCESS

Part II

89

Improve your Skills

Cut a section of a joint with fitting to examine the penetration of solder in the fittings

capillary.

Figure 16: Brazed copper-T

examples/cut away

Figure 17: Nitrogen protective

brazing examples

Penetration of solder (perfect)

Penetration of solder (insufficient)

Example of Nitrogen

protective brazing

Straight brazing copper/copper

joint with Nitrogen

OXIDE FORMATION

Straight brazing copper/copper

joint without Nitrogen

Always follow specific safety regulations!

(see also chapter safety)

SKILLS AND OPERATION

FLARING, THE PROCESS

90

Part II

Chapter 8: Flaring, the Process

Preface

Because of its exceptional formability, copper can be formed as desired at the job site.

Flaring is a mechanical way of joining pipe work.

While a copper tube is usually joined by soldering or brazing, a mechanical joint may be

required or preferred at times. Flared fittings are an alternative when the use of an open

flame is either not desired or impractical.

Flared joints (and screwed connections) should be kept as minimal as possible. Leak prevention

requires the design of a ‘sealed system’ as far as possible. Check the availability of

‘brazed in’ components and use them wherever possible!

In particular, flared joints must not be used to connect expansion valves.

SKILLS AND OPERATION

FLARING, THE PROCESS

Part II

91

TT

Page 5

Figure 1

TT:

Page 6

Figure 3

TT:

Page 6

Figure 4

(1)

Cut the tube

Use a wheel cutter rather than

a hacksaw in order to prevent

swarf entering the tube.

Remove internal burrs

A deburrer or reamer can be

used to remove internal burrs.

Clean the surfaces

Dirt, debris and foreign

substances should be

removed from the tube

end by mechanical cleaning.

Figure 1: Cutting the tube

Figure 2: Removing of burrs

Figure 3: Cleaning the surface

References

Flaring Process Steps

TT

Page 11

Figure 11

TT

Page 11

Figure 11

SKILLS AND OPERATION

FLARING, THE PROCESS

92

Part II

The flaring tool (example)

The flaring tool consists of:

Flaring bar (holding tool)

Clamp tool

Flaring cone

Holding bores different

diameters

Assemble the flaring tool

with tube and flare-nut

Place the flare-nut over the

end of the tube with the threads

close to the end being flared.

Insert the tube between the

flaring bars of the flaring tool.

Opening of the flaring bars must

match the diameter of the tube

being flared.

Fabricate the flare

Align the compression cone

on the tubing’s end and tighten

the screw. As you turn the

handle, the cone flares the

tubing’s end.

Figure 4: Flaring tools

Figure 5: Flaring arrangement

Figure 6: Flare fabrication

References

SKILLS AND OPERATION

FLARING, THE PROCESS

Part II

93

Inspect your work

Inspect your work after removing

the tubing from the flaring tool.

If the tube end has splits, cut

off the flared portion and repeat

the process.

It is essential to examine the tight

position of :

• male flare union

• female flare-nut

• flared copper tube

Tight and clean fitting is

requested.

Assembling

Position the flare union against the

flared end of the tubing and slide

down the nut. The fitting should be

easily tightend by hand if done

properly. Additional pipe jointing

or sealing compound (e.g. oil) is

not necessary.

Figure 7: Flare inspection

Figure 8: Flared connection positioning

References

SKILLS AND OPERATION

FLARING, THE PROCESS

94

Part II

Tightening

It is now time to tighten the

joint by placing one wrench on

the union and one on the nut.

Do not ‘over-tighten’ a flare

joint!

Once the parts fit by hand,

give them a half turn on each

nut/wrench to create a gas

tight join.

Final result

Figure 9: Flared connection tightening

Figure 10: Copper tube with flare,

flare-nut and adapter

References

SKILLS AND OPERATION

DOMESTIC REFRIGERATION

Part II

95

Chapter 9: Domestic Refrigeration

Preface

Domestic refrigerators are amongst the most common electric appliances in the world, for

instance being present in 99.5% of European and American homes. They may consist of

either a cooling compartment only (a larder refrigerator) or a freezing compartment only (a

freezer) or contain both.

Some refrigerators are now divided into four zones for the storage of different types of food:

• –18°C or 0°F (freezer)

• 0°C or 32°F (meats)

• 4°C or 40°F (refrigerator)

• 10°C or 50°F (vegetables), for the storage of different food types.

The following chapter is about the maintenance and repair of the domestic refrigeration

systems.

• With refrigerant shortage (leak) the refrigerant entrance at

the condenser is warm, the outlet cold

• With iced-over evaporator the heat transfer is very low

• With reduced compressor capacity the heat transfer is very low

Before opening a hermetic refrigerant cycle

it is essential to have first visible, sensitive

and audible impressions which can directly

lead to fault identification.

The first system cycle evaluation consists of:

(1) Heat transfer at the condenser

(2) Temperature of the filter-drier

(3) Noise level of the compressor

(4) Heat emission of the compressor

(5) Situation of hoar frost at the evaporator

Figure 1: View of a refrigerant circuit (6) Capacity of the compressor

First Steps

SKILLS AND OPERATION

DOMESTIC REFRIGERATION

96

Part II

MI

Page 47

Figure

11 (4)

Placing a fridge / freezer

It is very important that the fridge/

freezer is placed with sufficient

surrounding for heat transfer (air

circulation).

Pay attention that the condenser

is free of dust or dirt and that no

items obstruct the ventilation area.

Placing of a fridge/freezer close

to other heat sources must be

avoided.

It is necessary to clean the

condenser regularly.

Use a common thermometer and

a glass of water for inside temperature

measurements.

The evaporator must not be icedover.

This will hinder the heat absorption

in the refrigerated area.

Check that there is a sufficient

ice formation (hoar frost).

The fridge/freezers door gasket

must lie perfectly close at the

body.

Use a hair-drier to work on spots

where the gasket does not fit.

Figure 2: Freezer air circulation

Figure 3: Freezer temperature

measuring

Figure 3a: Refrigerator wall

(evaporator area) with hoar frost

References

SKILLS AND OPERATION

DOMESTIC REFRIGERATION

Part II

97

MI

Page 47

Figure 11

Connect the sensor of the

electronic thermometer to the

securing clip of the thermostat

sensor to measure switch-on

and switch-off temperatures.

Check that the lighting switches

off while you close the door.

Adjust the thermostat slightly

above medium position of the

temperature adjustment range.

e.g.: Position 4 of range 7

Position 2.5 of range 4

Does the thermostat cut-off?

Compare cut-off/cut-on

temperatures with the thermostat

manufacturer’s technical

information.

Figure 4: Sensor positioning

References

If a hermetic refrigerating system is to function correctly and to have a reasonable long life,

it is essential that the amount of impurities present in the system, i.e. moisture, foreign gases,

dirt etc., are being kept at a minimum.

This fact must be taken into consideration when repairs are to be made and the necessary

precautions must be taken. Before commencing repairs, especially those which require the

opening of a hermetic refrigerant cycle, make sure that all other possible faults have been

eliminated and that an exact diagnosis of the problem has been made.

If the first system cycle evaluation and measurements indicate that it is necessary to open

the hermetic system, we have to proceed as follows:

Figure 5: Temperature adjustment range

Refrigerant Cycle Opening

References TT Page 5-Figure 2, RHC Page 24-Figure 9

SKILLS AND OPERATION

DOMESTIC REFRIGERATION

98

Part II

RHC:

Page 24

Figure 9

For gauge connection and

pressure/temperature reading,

place piercing plier connected

with refrigerant hose to the

process tube (charging tube)

at the compressor. Continue

system cycle analysis with

operating compressor.

Figure 6: Steps when opening a refrigerant cycle

Figure 7: Placement of piercing

plier at process pipe

References

SKILLS AND OPERATION

DOMESTIC REFRIGERATION

Part II

99

RHC

Page 24

Figure 9

TT

Page 5

Figure 2

TT

Page 5

Figure 1

For refrigerant gas recovery, place

one additional piercing plier

directly on the filter-drier’s surface

(high pressure side). This enables

refrigerant gas recovery from

both, high and low pressure sides

of the system. Additional, if the

capillary tube is mechanically

blocked, refrigerant will remain

at the high pressure side of the

system. For further explanation

of the refrigerant gas recovery

process see also chapter ‘refrigerant

recovery, recycling and

containment in the field’.

After entire emptying of the refrigerant

cycle, cut the capillary tube

at the filter-drier outlet (distance

from filter-drier approx. 3 cm).

Avoid burrs and deformation of

the capillary tube.

Cut the filter-drier with a tubecutter

if sufficient condenser

tube length (steel) is available.

This action enables you to remove

bounded humidity and residues

together with the filter-drier.

Figure 8: Placement of an additional

piercing plier at the filter-drier

Figure 10: Cutting of the filter-drier

Figure 9: Cutting of the capillary tube

References

SKILLS AND OPERATION

DOMESTIC REFRIGERATION

100

Part II

MI

Page 51

Figure 18

If a sufficient tube length is not

available, proceed as follows:

For safety reason, destroy the

filter-drier with a side cable

cutter plier close to the filterdrier

outlet. Unbraze the filterdrier

and clean the steel tube

of the condenser’s outlet

thoroughly with a wire-brush.

Brazing torch

Filter-drier

Destroyed filter section

Side cable cutter

Here the capillary was

cut in figure (9)

If a reduced hermetic

compressor capacity is

assumed, complete a

capacity test.

Figure 11: Destruction of a filter-drier

Figure 12: Capacity test

References

SKILLS AND OPERATION

DOMESTIC REFRIGERATION

Part II

101

RHC

Page 24

Figure 9

Dry Nitrogen (N2) is connected

now to the valve on the process

pipe.

The pressure regulator of the

Nitrogen supply cylinder is adjusted

to a maximum of 10 bar.

The Nitrogen flow will enter the

system passing the process tube,

the compressor, the evaporator

with the connected capillary tube

Figure 13: Nitrogen connection and the condenser.

to the process pipe

Flushing the System with Nitrogen N2

Nitrogen discharges now at the open end of the condenser (previously connected to the

filter-drier inlet) and the open end of the capillary tube. Hold a rag at both open ends because

remaining compressor lubricant may come with the purged Nitrogen. The Nitrogen

flushes the system and takes humidity etc.The blowing process also allows the localization

of any obstructions in the piping.

Plan the repair work so that the refrigerating system will not be open for more than 10–15

minutes.

Assemble the special equipment required for the repairs.

Assemble any spare parts required.

References

SKILLS AND OPERATION

DOMESTIC REFRIGERATION

102

Part II

While assembling the refrigerated section, service valves (Schrader valves) must not be used

because of the high risk of leakage. Domestic appliances require a sensitive and accurate

refrigerant charge and the correct charging amount is very low compared with commercial

or air-conditioning systems. For domestic appliances only a few gram of leakage per year

will reduce the refrigerators/freezers efficiency resulting in increased electricity consumption.

Prevent intentional leaks and provide a hermetic system (refrigerant cycle) without

screwed connective service ports.

When brazing the filter-drier and the capillary tube, note that the thin capillary

cannot withstand high temperatures due to the risk of melting and the torch’s

heat must therefore be confined from the filter.

Preferably install a filter-drier with additional process tube (high pressure side)

if available.

Use copper brazing rods (solder) with approximately 1.5% to 4% of silver content

and phosphorus for copper-copper connections.

Use silver brazing rods (solder) coated with flux or separate flux paste for coppersteel

connections.

Clean all brazing joints thoroughly with a wire brush and check the condition

(appearance) with an inspection mirror.

References

TT

Page 15

Figure 18

TT

Page 7

Figure 5

Figure 14: Brazing of the filter-drier

System Assembling – Create a Hermetic System

SKILLS AND OPERATION

DOMESTIC REFRIGERATION

Part II

103

Connect the quick coupler now

to the prepared refrigerant

cycle at low and high pressure

side using the service quick

coupler.

Connect the evacuation and

charging station to the previously

connected quick coupler.

1. Low pressure side

2. High pressure side

Connect the Nitrogen cylinder

to the charging station.

Pressurize the system with dry

Nitrogen while transferring the

gas from both, the high and low

pressure side up to a system

pressure of a maximum of 10 bar.

References

TT

Page 9

Figure 8

RRRE

Page 38

Figure 8

TT

Page 15

Figure 19

Figure 15: Connection of quick coupler

and refrigerant cycle

Figure 16: Evacuation and charging

station

Figure 17: Nitrogen cylinder with

pressure regulator

SKILLS AND OPERATION

DOMESTIC REFRIGERATION HC

104

Part II

Chapter 10: Domestic Refrigeration HC

Preface

Hydrocarbons (HCs) are widely used in today’s modern refrigeration appliances (capillary

tube operational domestic and small commercial systems). Within the foreseeable future,

CFC, in particular for servicing purpose, will become unobtainable. In new production of

household appliances CFC-R12 is widely replaced by HFC-R134a and HC-R600a. HCs will

become more important in the future, as most fluorinated gases have a high impact on

global warming.

HC refrigerants are flammable if mixed with air and ignited, and should therefore only be

used in appliances which fulfil regulated safety requirements.

In order to carry out service and repair on HC systems, the service personnel must be properly

trained to be able to handle a flammable refrigerant.This includes knowledge on tools,

refrigeration cycle components and refrigerants, and the relevant regulations and safety precautions

when carrying out service and repair.

The refrigerant must be stored and transported in approved containers. Best possible in 450 g

aluminium cylinder (within two containers maximum transported in a service car). In general,

replaced compressors containing refrigerant (not only HC containing compressors) residues

must be sealed before being transported.

Electronic

charging

scale

Pressure

regulator

HC-R600a

charging

cylinder

Figure 1: HC Refrigerant charging set

SKILLS AND OPERATION

DOMESTIC REFRIGERATION HC

Part II

105

Important Note:

For safety reasons a practical limit of 8 g /m3 of Hydrocarbon refrigerant should

not be exceeded in a closed space or room.

HCs are heavier than air. The concentration (if refrigerant is exposed) will always be highest

at floor level.

Do not release the refrigerant close to basements, canalisation etc.The working room/area

must be always sufficient ventilated.

To avoid any dangerous circumstances, open flames should be avoided. The best possible

way for domestic appliances service and repair is to use e.g. LOKRING connections and

joints.

The use of dry Nitrogen for system service and repair plays an important role:

• Refrigerated system flushing

• Leak test

• Removal of sectional restrictions (dirt or residues)

Abstract:

The service technician is familiar with the dangers related to flammable HC

refrigerants.

•There is no risk of sparks forming near the work area.

•Do not smoke or use naked flame or other means of heat.

Therefore, no brazing on the system is preferred.

•Electrical appliances used during the service must not produce sparks.

•Arrange good ventilation in the work area.

•Do not let the refrigerant flow into basement openings, low lying rooms,

sewer systems etc. as HCs are heavier than air.

•Safety rules for handling, storage and transport of combustible

refrigerant applicable in the various countries must be followed.

SKILLS AND OPERATION

DOMESTIC REFRIGERATION HC

106

Part II

• With refrigerant shortage (leak) the refrigerant entrance at

the condenser is warm, the outlet cold

• With iced-over evaporator the heat transfer is very low

• With reduced compressor capacity the heat transfer is very low

Before opening a hermetic refrigerant cycle

it is essential to have first visible, sensitive

and audible impressions which can directly

lead to fault identification.

The first system cycle evaluation consists of:

(1) Heat transfer at the condenser

(2) Temperature of the filter-drier

(3) Noise level of the compressor

(4) Heat emission of the compressor

(5) Situation of hoar frost at the evaporator

(6) Capacity of the compressor Figure 2: View of a refrigerant circuit

Placing a fridge / freezer

It is very important that the fridge/freezer

is placed with sufficient surrounding for

heat transfer (air circulation).

Pay attention that the condenser is free of

dust or dirt and that no items obstruct the

ventilation area.

Placing of a fridge/freezer close to other

heat sources must be avoided.

It is necessary to clean the condenser

regularly.

Figure 3: Freezer air circulation

First Steps

SKILLS AND OPERATION

DOMESTIC REFRIGERATION HC

Part II

107

MI

Page 47

Figure

11 (4)

MI

Page 47

Figure

11 (1-2)

Use a common thermometer

and a glass of water (as indicated

above) for inside temperature

measurements.

The evaporator must not be icedover.

This will reduce the heat absorption

in the refrigerated area.

Check that there is a sufficient ice

formation (hoar frost).

The fridge/freezers door gasket

must lie perfectly close at the body.

Use a hair-drier to work on spots

where the gasket does not fit.

Figure 4: Freezer temperature measuring

References

Connect the sensor of the

electronic thermometer to the

securing clip of the thermostat

sensor to measure switch-on

and switch-off temperatures.

Check that the lighting switches

off while you close the door.

Adjust the thermostat slightly

above medium position of the

temperature adjustment range.

e.g.: Position 4 of range 7

Position 2.5 of range 4

Does the thermostat cut-off?

Compare cut-off/cut-on

temperatures with the thermostat

manufacturer’s technical

information.

Figure 5: Sensor positioning

Figure 6: Temperature adjustment range

SKILLS AND OPERATION

DOMESTIC REFRIGERATION HC

108

Part II

If a hermetic refrigerating system is to function correctly and has a reasonable long life, it

is essential that the amount of impurities present in the system, i.e. moisture, foreign gases,

dirt etc., is being kept at a minimum.

This fact must be taken into consideration when repairs have to be made, and the necessary

precautions must be taken. Before commencing repairs, especially those which require

the opening of a hermetic refrigerant cycle, make sure that all other possible faults have

been eliminated and that an exact diagnosis of the problem has been made.

If the first system cycle evaluation and measurements indicate that it is necessary to open

the hermetic system, we have to proceed as follows:

RHC

Page 24

Figure 9

For gauge connection and pressure/temperature reading, place piercing plier

connected with refrigerant hose to the process tube (charging tube) at the compressor.

Continue system cycle analysis with operating compressor.

Figure 7: Placement of piercing plier

References

Refrigerant Cycle Opening

SKILLS AND OPERATION

DOMESTIC REFRIGERATION HC

Part II

109

If the compressor does not have to be replaced, the oil is degassed in the compressor

by letting the compressor run for about one minute.

Never start the compressor under vacuum; it would risk damaging of the motor.

RHC

Page 24

Figure 9

To remove the refrigerant gas,

place one additional piercing plier

directly on the filter-drier’s surface

(high pressure side).

The hose (vent line) is carried outside

and connected to the ‘free

ambient’, e.g. through a window

opening.

The vent line must have an inner

diameter of minimum 10 mm

or 3/8”.

Figure 8: Placement of

additional piercing plier

The end of the hose is carried

through, e.g. an open window.

This will be a ‘vent line’ to remove

the flammable refrigerant to the

safe outside area.

• Open window or door

• Vent line

Figure 9: Open window as vent line

RHC

Page 22

Figure

5 (6)

References

References

SKILLS AND OPERATION

DOMESTIC REFRIGERATION HC

110

Part II

As follows, the system can be

‘blown through’ with Nitrogen.

Nitrogen will flush the system

while taking residues of refrigerant

and venting to the ambient

atmosphere.

RHC

Page 24

Figure 9

TT

Page 15

Figure 19

Figure 10: Nitrogen flush

After flushing the Nitrogen, the cylinder pressure regulator is closed.The vent line at the filterdrier

is dismounted.

• Connect the vent line to vacuum pump outlet on the exhaust port.

• Connect the hose of the vacuum pump suction port to the valve on the filter-drier.

References

SKILLS AND OPERATION

DOMESTIC REFRIGERATION HC

Part II

111

• Suction hose connected to the

piercing pliers on filter-drier

• Suction hose connected to the

vacuum pump suction port

• Vent line on exhaust port of

the vacuum pump

• Vent line to the outside area

Figure 11: HC refrigerant recovery

with vacuum pump and vent line

RHC

Page 24

Figure 9

RRRE

Page 37

Figure 7

RHC

Page 22

Figure

5 (6)

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The refrigerating system is now ready for the first evacuation. Evacuate to a pressure of

approximately 5 mbar.

The vent line must have a minimum inner diameter of 10 mm (3/8”)!

There must not be any appreciable overpressure at the exhaust port of the vacuum

pump, as this may damage the vacuum pump!

End the first evacuation process through switching off the vacuum pump.

Open the valve on the Nitrogen tank pressure regulator and flush the total arrangement of

refrigeration system, piercing pliers, vacuum pump and vent line by less than 1 bar (low

pressure).

Regulate the working pressure with the reducing valve and equalize the pressure into the

system.

The Blowing Process

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➡

➡

➡

➡

➡

➡

➡

Figure 12: Nitrogen blowing process

• Nitrogen blowing

process by low pressure

• Vent line to the outside area

References

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114

Part II

TT

Page 5

Figure 2

TT

Page 5

Figure 1

MI

Page 51

Figure 18

After the entire blowing of the

refrigerant cycle disconnect the

vacuum pump and vent line.

Cut the capillary tube at the

filter-drier outlet (distance

from filter-drier approx. 3 cm).

Avoid burrs and deformation

of the capillary tube.

Cut the filter-drier with a tubecutter

if sufficient condenser tube

length (steel) is available.

This action enables you to remove

bounded humidity and residues

together with the filter-drier.

If a reduced hermetic compressor

capacity is assumed, complete a

capacity test.

Figure 14: Cutting of the filter-drier

Figure 15: Adjustment for a capacity test

Figure 13: Cutting of the capillary tube

Removing Filter-Drier /

Compressor Capacity Test

References

RHC

Page 24

Figure 9

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115

Dry Nitrogen (N2) is connected

now to the valve on the process

pipe.

The pressure regulator of the

Nitrogen supply cylinder is adjusted

to a maximum of 10 bar.

The Nitrogen flow will enter the

system passing the process tube,

the compressor, the evaporator

with the connected capillary tube

and the condenser.

TT

Page 15

Figure 19

Nitrogen discharges now at the open end of the condenser (previously connected to the

filter-drier inlet) and the open end of the capillary tube. Hold a rag at both open ends

because remaining compressor lubricant may come with the purged Nitrogen. The blowing

process also allows the localization of any obstructions in the piping.

Plan the repair work in a way that the refrigerating system and new parts will not be open

for more than 10–15 minutes.

• Assemble the special equipment required for the repairs.

• Assemble any spare parts required.

• Mount a service filter, which is larger than the filter originally used and

(if possible) with additional process pipe connection. The filter-drier must

be hermetically sealed until it is mounted.

The refrigerating system is prepared for assembly using a tube joining system by pressing

connections.

Figure 16: Nitrogen flow adjustment

Evaporator and Condenser Check

References

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Part II

Connect the quick coupler now

to the prepared refrigerant cycle

at the low and high pressure side

using the service coupler.

Connect a 4-valve manifold

gauge set to the system.

Low pressure side

High pressure side

Nitrogen supply

Connect the Nitrogen cylinder to

the centre port of the manifold

gauge set.

Pressurize the system with dry

Nitrogen while transferring the

gas from both, the high and low

pressure side up to a system

pressure of a maximum of 10 bar.

Figure 17: Connection system for

a leak test

RHC

Page 19

Figure 2

TT

Page 15

Figure 19

TT

Page 9

Figure 8

Leak Test

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117

Figure 18: Bubble indicating a leak

Carry out a leak-test ...

1. By standing pressure with

closed valves and gauge for

pressure observation. For very

small leaks a pressure test may

take up to 24 hours. A pressure

drop indicates a leak.

and

2. With soap water and a brush,

adding this liquid to all joints while

observing if the liquid creates

bubbles. Bubbles indicate a leak.

References

MI

Page 43

Figure 5

Bring all pipes carefully into the correct position (e.g. protruding tubes).

If the system is identified as leak free, blow off the Nitrogen into the atmosphere.

The system is now ready for the final evacuation and charging.To keep the content of noncondensability

and humidity in the system to a minimum, the system must be evacuated to

a vacuum as low as possible before charging is carried out (0.5 mbar, 50 Pa, 375 micron).

The vacuum attained must be checked with a vacuum gauge.

General rule for evacuation time required:

1. One side evacuation at the compressor’s process tube only, minimum

time required is 30 minutes.

2. Two side evacuations at the compressor’s process tube and the filter-drier’s

process tube, minimum time required is 15 minutes.

Check for stability of the vacuum by closing the valve for the vacuum pump. If the vacuum

gauge needle falls appreciably, possible leakage in the system is indicated or hose connections

of the service equipment to the refrigerator/freezer are not properly fitted.

Evacuation and Charging the System

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Connect the quick coupler now

to the prepared refrigerant cycle

at the low and high pressure side

using the service coupler.

• 4-valve manifold

• Vacuum pump with

vacuum gauge

• HC refrigerant charging

cylinder on scale

References

TT

Page 9

Figure 8

RHC

Page 19

Figure 2

Figure 19: Two side system

evacuation and charging

SKILLS AND OPERATION

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119

Figure 20: Pressing equipment

for system sealing

When a stable vacuum has been achieved, close the valve for the vacuum gauge and commence

charging.

The amount of refrigerant to be added is specified in grams or oz on the rating plate.

Charging process:

1. Charge 1/3 of the total charging amount gaseous into the refrigerated system.

2. Switch on the compressor.

3. Add the remaining charging amount slowly into the system.

4. Observe the gauge and check the system’s operating situation.

References

TT

Page 7

Figure 6

1. Pinch the process tube(s) with

pliers twice. One pinch-off in

90° to the process pipe and

one in 45° to the process pipe.

2. Remove pinch-off pliers.

3. Seal the process tubes using a

stopper device1.

• Stopper device

Same process at the filter-drier’s

process tube (if present).

1 Stopper device, e.g. manufactured by Lokring.

Seal the System

References

SKILLS AND OPERATION

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Part II

Figure 21: Final leak test with

electronic leak detector2

2 e.g. STARTEK from REFCO

MI

Page 42

Figure 2

System check and final leak test

After the charging process the adjustment and functioning of control devices

must be checked. The system must be operated until sufficient system conditions

are visible.

Meanwhile temperature and pressure values should be recorded. After the

disconnection of gauges and hoses a final leak test has to be performed.

Use again soap water and/or an electronic leak-detector and you will find that

there are common places to check. The following lists some very common leak

locations:

• Flare-nuts

• Service valve: packing, access fitting, mounting

• Cracked brazed joint in piping

• Rotted evaporator end bends

• Pipes rubbing together

• Cracked ferrous brazed in accessory

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121

Chapter 11: Pressing, the Process

Preface

Alternatively to brazed joints, especially in domestic refrigeration and for systems operated

with Hydrocarbons (combustible refrigerants like R-600a and R-290), and also for the use in

small and medium AC systems and MAC, pressed tube connections are a safe and reliable

solution.

The tube pressing connection technology3 represents a proven method of producing hermetically

sealed metal-to-metal tube connections.

Features of the tube pressing connection technology:

• Permanent hermetically metal-to-metal sealing

• Unproblematic connection of tubes consisting of different materials

• No special preparation of the tubes necessary

• Easy and fast assembly

Pressure and Temperature Area

The above mentioned tube connections are designed for a working pressure of 50 bar

(depending on the tube material) with fourfold security and for the range of temperature

from –50°C up to +150°C ( –58°F up to 302°F).

Material Affiliation

The tube connections are made of the materials aluminium and brass.

Brass connectors, both ‘00’ series, for tube diameters 3/8“ (9.53 mm) and above, and all

sizes of ‘50’ series are usually supplied with connectors (adaptors) made from steel, with

a yellow coloured zinc plate galvanization.

The affiliation of the connectors depends on the material of the tubes to be connected and

is shown in the following figure.

3 Tube connections manufactured e.g. by ‘Vulkan Lokring Rohrverbindungen GmbH’

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Part II

Tube Material Combination

Tube Connectors Material

Aluminium

Aluminium

Aluminium

Brass

Brass

Brass

Aluminium

Aluminium

Aluminium

Copper

Copper

Steel

Aluminium

Copper

Steel

Copper

Steel

Steel

Figure 1: Tube connectors material combinations

Figure 2: Tube connection couplings

Tube connection coupling

for double sided assembly (series 00)

Tube connection coupling

for single sided assembly (series 50)

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123

Figure 3: Tube connection coupling

Figure 4: Tube coupling

Example of a tube connection coupling

A tube connection coupling consists of two tube connections and one tubular joint for the

acceptance of the two tube endings.

In condition of delivery, the tube connections are pre-assembled on the fitting, the bigger

end of the conical bore is pressed onto the outwards fit of the joint.

During assembly the tubes which are to be connected have to be pushed into the fittings

end. With the use of a ‘hand assembling tool’ the locking rings are pushed over the fitting.

Due to the special inner profile of a tube connector (e.g. Lokring), the diameter of the connection

is reduced until it is in absolute close contact with the outer surface of the tube

which is to be connected, and pinches it by a tight reduction.

Tube Locking Joint Locking Tube

Ring Ring

Tube Locking Locking Joint

Ring Ring

After Assembly Before Assembly

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Despite the high metal/metal pressure it is not always possible to seal deep surface porosity

and longitudinal grooves which might have a negative effect on the tightness of the tube

connection.

In order to obtain additional safety, the surfaces of the tube ends have to be moistened

with an anaerobic liquid. It settles in the unevenness of the tube surface and hardens there.

The curing time is dependent on various factors. After the curing of the liquid, the connection

can be loaded with pressure or vacuum.

Figure 5: Lokprep, anaerobic liquid

Figure 7: Assortment box for refrigeration

Lokprep 65G

Anaerobic filling and sealing

Medium contains methacrylic ester

Available in 15 or 50 ml

Figure 6: Hand assembling tool

Safety Recommendations

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125

Figure 8: Lokring connector brass

Figure 9: Lokring connector aluminium

Figure 10: Lokring reducer aluminium

Lokring connector (double sided assembly)

made of brass for joining of tubes

1.6 to 11 mm

Brass connectors for tube materials:

Cu/Cu; Cu/St; St/St

Lokring connector (double sided assembly)

made of aluminium for joining of tubes

2 to 11 mm

Aluminium connectors for tube materials:

Al/Al; Al/Cu; Al/St

Lokring reduced connector (double sided

assembly) made of aluminium for joining

of tubes

Aluminium reduced connectors for tube

materials:

Al/Al; Al/Cu; Al/St

Connection Examples

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Part II

Lokring tee connector (single sided

assembly) made of brass for joining

of tubes 6 to 28.6 mm

Brass tee connectors for tube materials:

Cu/Cu; Cu/St; St/St

Lokring tee reduced connector

(double sided assembly) made

of brass for joining of tubes

e.g. ø 6 mm and ø 2 mm with

tee ø 6 mm: Lokring 6/6/2 NTR Ms 00

(capillary tube insertion)

Brass tee reducer for tube materials:

Cu/Cu; Cu/St; St/St

(e.g. domestic appliances)

Figure 11: Lokring tee connector

Figure 12: Lokring tee reducer

with capillary tube insertion

Figure 13: Filter-drier with tube ends

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127

Figure 14: Tube cleaning in

a rotational motion

Figure 15: Coating with Lokprep

as anaerobic liquid

Figure 16: Rotating connection assembly

Figure 17: Pressing the tube connection

Surface cleaning

Before assembling the tube connection,

clean the tube ends with a scouring pad.

To avoid longitudinal grooves clean the

tube ends in a rotational motion (not in

longitudinal direction of the tube).

Apply anaerobic liquid

The ends of the tubes have to be

coated with an anaerobic liquid.

Rotate connection assembly

The tube ends have to be inserted into

the tube connection until the stop.

For a better distribution of the anaerobic

liquid the tube connection has to be

rotated at 360°.

Press locking rings

Tube connector assembly with hand

assembly tool.

Assembly of the Tubes

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Example tee connector

Tee connector assembly and quick service

connector

• Lokring tee connector

• Quick service connector

Compressor assembly

Compressor assembly with Lokring couplers

Figure 18: Example of a tee connector

Figure 19: Example of a compressor assembly

The tube locking ring has not been pushed

to the end

The tube has not been inserted to the end

The bending point is too close to the joint

ending

Final Leak Check

After all couplers and connectors are done, check system for leaks. Use dry Nitrogen

to pressurize the system up to a maximum pressure of 10 bar.

Figure 20: Assembly faults

SKILLS AND OPERATION

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129

This picture shows a hand affected by

contact with liquid refrigerant.

Chapter 12: Refrigerant Recovery, Recycling and

Containment in the field

Preface

The transfer of any kind of refrigerants into storage and recycling cylinders is a dangerous

practice. For this reason we always have to work according to strict safety regulations. Read

carefully refrigerant manufacturer`s safety advices for the handling of refrigerants.

Think before acting!

Pressured and liquified gas may quickly create dangerous situations.Through improper use,

liquid gas can cause severe injury to skin, eyes and respiratory tracts.

There is always a strict smoking ban in all work areas.Work areas must be ventilated if refrigerant

is present. Refrigerants are heavier than air and reduce the content of oxygen in the

air. Refrigerants are not visible and do not smell. Breathing refrigerants may not be noticed

and lead to a blackout and/or death.

The touch of voltage-carrying operating supplies causes life threatening situations.

Figure 1: Affected hand

Safety Recommendations

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Special care should be taken:

• Not to overfill the refrigerant cylinder.

• Not to exceed the working pressure of each cylinder. Check stamping on cylinder!

• Safety codes recommend that closed tanks are not be filled over 80%

of volume with liquid.

• Never transport an overfilled cylinder.

• Not to mix grades of refrigerant or put one grade in a cylinder labelled for another.

• To use only clean cylinders, free from contamination by oil, acid, moisture, etc.

• To visually check each cylinder before use and make sure all cylinders are regularly

pressure tested.

• Recovery cylinders have a specific indication depending on the country (yellow

mark in US, special green colour in France) in order not to be confused with

refrigerant container.

• Not to store a filled cylinder at a high ambient temperature and exposed to the sun.

References

RHC

Page 27

Figure 13

Starting with

cylinder 80%

full by volume

Starting with

cylinder 90%

full by volume

Refrigerant expands when it gets warm and may cause tank explosion if

overfilled.

Figure 2: Cylinder temperature and

internal liquid expanding space

References

SKILLS AND OPERATION

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131

The cause was for

each overfilling with

refrigerant.

Cylinder should have

separate liquid and

gas valves and be

fitted with a pressure

relief device.

Figure 3: Examples of bursted cylinders

Figure 4: Cylinder with separate liquid

and gas valves

Photos courtesy of Manchester Tank & Equipment

RHC

Page 27

Figure 13

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Purchased refrigerants are packed in both disposable and returnable shipping containers.

Disposable cylinders often indicate very bad practice. CFC refrigerants even purchased today

often have a bad quality (contaminated).These containers are generally discarded after use

and a lot of refrigerant is released into the atmosphere due to disposable cylinders.

Refrigerant manufacturers have voluntarily established a colour code system to identify their

products, with both disposable and reuseable cylinders painted or otherwise distinguished

by the following common refrigerant colours and identification:

R-11 Orange R-12 Grey R-22 Medium Green R-502 Orchid

R-134a Light Blue R-404 Orange R-507 Blue Green R-407C Med. Brown

Table 1: Refrigerant cylinder colours

Figure 5: Disposable refrigerant cylinder

These cylinders are not recommended for refilling!

Only use DOT or TÜV standard approved refrigerant recovery

cylinder for recovery purpose!

Purchased Refrigerants

References

RHC

Page 27

Figure 13

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133

Figure 6: Recovery with OFP

connection (float-switch)

Figure 7: Connection of OFP to the

socket at the recovery cylinder

Figure 8: Arrangement of recovery cylinder

and recovery unit with OFP connection

There are three different

possibilities for overfill

protection (OFP)!

1. The cylinder is equipped with

a liquid level float switch.

Recovery unit will cut-off if 80%

of filling volume is achieved.

Recovery cylinder

Recovery unit

Inline filter with hose (inlet)

OFP cable connection to

recovery unit

RHC

Page 27

Figure 13

References

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MI

Page 46

Figure

9 (1)

MI

Page 46

Figure

9 (1)

Figure 9: Recovery with cylinder on

weighing scale and connected OFP

Figure 10: Arrangement of cylinder, scale

and recovery unit for manual observation

2. Recovery cylinder is placed

on scale.

Recovery unit will turn off if

the adjusted weight amount

is achieved.

Recovery cylinder

Recovery unit

Inline filter with hose (inlet)

Weighing scale with

connection to the recovery

unit

3. Recovery cylinder is placed

on scale.

Operator turns off the recovery

unit manually if 80% of cylinder

charge is achieved.

Warning: An 80% shut off switch does not always prevent overfilling. Any

technician using an 80% shut off switch must be aware of the liability and

safety risks that come along with their use.

Further explanation of this topic can be found in the section below

‘Methods of refrigerant recovery – push and pull-method’.

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135

Using recovery units

Recovery units are connected to the system by available service valves, or line tap valves,

or line piercing pliers. Some of them can handle refrigerants in both liquid and vapour form

and some have onboard storage vessels.

Take care not to let the compressor suck in liquid refrigerant if the compressor is not protected

against liquid strokes.

The above sketch demonstrates a recovery unit layout example with liquid stroke protection

(suction pressure regulator) and an oil based compressor.

There are three types of recovery apparatus available. These are self-contained, system

dependent and passive:

Self-contained:

A self-contained recovery unit has its own compressor (or other transfer mechanism) to

pump refrigerant out of the system. It requires no assistance from any component in the

system that is being recovered.

Figure 11: Refrigerant flow chart example (recovery unit)

Refrigerant Recovery Process

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System-dependent:

System-dependent recovery equipment, on the other hand, relies upon the compressor in

the appliance and/or the pressure of the refrigerant in the appliance to assist in recovery

of the refrigerant. Recovery that uses only a chilled recovery tank falls under this category.

Passive:

Passive recovery refers to a deflated bag (recovery bag), e.g. for small domestic appliances,

which is used to store small amounts of refrigerant near or slightly above atmospheric pressure

(0.1 bar).

The methods of recovery depend upon the type of refrigerant being recovered. This is usually

divided into two general groups: High pressure, where the boiling point of the refrigerant

is between –50°C and 10°C at atmospheric pressure, and low pressure where the boiling

point is above 10°C at atmospheric pressure. High pressure refrigerants include CFC-12,

HFC-134a and HCFC-22, while low pressure refrigerants are CFC-11, CFC-113, HCFC-123

etc.

Gas recovery

The refrigerant charge can be

recovered in vapour recovery

mode as shown in this sketch.

On larger refrigeration systems,

this will take appreciably longer

than if liquid is transferred.

Connection hoses between

recovery units, systems and

recovery cylinders should be

kept as short as possible and

the diameter as large as

practicable.

Figure 12: Vapour recovery mode

References

MI

Page 46

Figure

9 (1)

Methods of Refrigerant Recovery

References

SKILLS AND OPERATION

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137

Liquid & oil recovery

If the recovery unit does not

have a built-in liquid pump (system

depending) or is otherwise

not designed to handle liquid,

then liquid can be removed from

a system using two recovery

cylinders and recovery unit. The

recovery cylinders must have

two ports and two valves, one

each for liquid and one each

for vapour connections.

This recovery set-up will also act

to separate the oil from the

cylinder connected to the inlet

port of the recovery unit.

‘Push and pull’ liquid

refrigerant recovery method

The recovery unit will pull the

liquid refrigerant from the disabled

unit when decreasing the

pressure in the recovery cylinder.

Vapour pulled from the recovery

cylinder by the recovery unit will

then be pushed back to disabled

unit’s vapour side.

Figure 13: Recovery system with two

cylinders for liquid and oil separation

Figure 14: ‘Push and pull’-recovery system

MI

Page 46

Figure 9

MI

Page 46

Figure

9 (1)

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Part II

To carry out refrigerant and oil tests it is necessary to remove a sample of refrigerant and

oil from the compressor or refrigeration system without undue release of refrigerant. The

procedure for this will vary depending on the arrangement of shut-off valves and access to

the refrigerant and oil available on the unit.

Test Refrigerant and Lubricant

for Contamination

Note: Refrigerant recovery 80% shut off switches

The 80% shut off sensors were originally intended to be a safety feature for refrigerant

recovery.

On most machines these switches simply turn off the recovery machine without stopping

the flow of refrigerant.This can result in an overfilled cylinder, becoming extremely dangerous

for the technician. This is a known hazard in these common situations:

1. During push-pull procedures, once a siphon is started, merely

powering off the machine, but does not prevent the tank from overfilling.

2. When using a tank with a large amount of cold refrigerant and recovering

from a system at a higher temperature, turning the machine off will not stop

the refrigerant from migrating to the coldest point (in this case, the recovery

tank) eventually overfilling the tank even with the machine off.

Warning: An 80% shut off switch does not always prevent overfilling. Any technician

using an 80% shut off switch must be aware of the liability and safety risks that come along

with their use.

Reminder: 80% shut off switches are not ‘walk-away’ features!

No process involving temporary connections and systems under

pressure should ever be left unattended!

References

SKILLS AND OPERATION

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139

Proprietary test kits are available which permit the refrigerant to be tested

for water contamination and acidity.

Figure 15: Oil-test at compressor

suction line

Figure 17: Taking oil-sample from

a hermetic compressor

RHC

Page

28/29

Figure

15,16,17

Figure 16: Refrigerant test

at cylinder

It is possible to test the oil in

some systems for acidity.

Acid in the oil indicates that

a burnout or partial burnout has

taken place, and/or that there

is moisture in the system, which

can cause a burnout.

Figure 18: Taking oil-sample from

a semihermetic compressor

RHC

Page

28/29

Figure

15,16,17

RHC

Page 28

Figure 15

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Recovered refrigerant may be reused in the same system from which it was removed or it

may be removed from the site and processed for use in another system, depending upon

the reason for its removal and its condition, i.e. the level and types of contaminants it may

contain.

Potential contaminants in a refrigerant are acids, moisture, non-condensable gases and

particulate matter. Even low levels of these contaminants can reduce the working life of a

refrigeration system.

Contaminated refrigerants (including those from a unit with a burn-out hermetic compressor)

are reusable provided they have been recovered with a recovery unit incorporating an oil

separator and filters (recycling unit).

Recycling units may be directly connected to the serviced system (e.g. MAC) or clean the

stored refrigerant from recovery or storage cylinder.

Main cleaning components of a common recycling unit are in general:

1. Compressor

2. Thermostatic expansion valve (TEV) or Constant Pressure Regulator (CPR)

3. Suction-accumulator or oil-seperator with oil-drain valve

4. Filter sections (one or more)

5. Non-condensable gases purge device (manual or automatic)

6. Condenser

7. Storage cylinder

Reuse of Refrigerant

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Figure 19: Refrigerant flow chart example of a recycling unit

Figure 20: Example combo-filter (recycling filter)

Removal and absorption of:

• Acid

• Moisture

• Particulate matter

Recycling filter must be regularly

changed according to manufacturers’

recommendation and

refrigerant contamination state.

References RRRE Page 34-Figure 3

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Vapour transfer

Mobile air-conditioning systems are normally equipped with service valves on the compressor’s

high and low pressure side. The refrigerant charge on such a system is rather small

and therefore only vapour transfer is required.

Connect both refrigerant hoses

from the MAC servicing unit low

and high pressure side to the

air-conditioning system’s service

ports as indicated.

Connect quick service couplers

to the service hoses if required.

Automatic and/or manual

air-conditioning system service

procedure follows:

- AC system data monitoring

and evaluation

- Refrigerant recovery

- Refrigerant recycling

- AC system repair

- AC system leak test

- AC system evacuation

- AC system charging

Figure 21: Mobile air-conditioning system

connected to a ‘refrigerant handling’ unit

Recovery from Mobile Air-Conditioning

System (MAC)

Passenger compartment

Front of car

Filter-drier

Receiver

Compressor

Low side

service port

Gauges

Expansion device

High side

service port

➡ ➡

➡ ➡

➡ ➡

➡ ➡

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Domestic refrigeration appliances have to be hermetically sealed – without exception.

It is possible to recover refrigerants from a hermetically sealed system, which has no service

valves. A piercing plier or a line-tap valve should be fitted to the refrigerant cycle (in most

cases the process tube or charging tube). These valves are only for servicing purposes and

should never be left permanently in place.Always remove these temporary valves to provide

a sealed hermetically system after service and repair.

Because of the small charge of

refrigerant, only vapour recovery

is needed.

It is recommended to

install valves (piercing plier

or line-tap valve) on both

and low pressure side

(if possible).

References

RHC

Page 24

Figure 9

RHC

Page 25

Figure 10

Figure 22: Installation of piercing pliers

Recovery from a Domestic Refrigerator

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Various refrigerant recovery technologies for domestic appliances

For the purpose of refrigerant recovery at small capillary systems we differentiate the use

of, e.g.:

1. Recovery unit and recovery cylinder

2. Refrigerant recovery hand pump with recovery cylinder or bag

3. Refrigerant recovery with vacuum pump and recovery bag

Refrigerant recovery with

recovery unit

• Place the recovery cylinder

on scale.

• Connect the recovery unit

outlet port to the liquid port

of the recovery cylinder.

• Connect the center port to the

manifold gauge set to the inlet

port of the recovery unit.

Incorporate an inline filter-drier.

• Connect low and high side of

the manifold gauge set to the

refrigerator’s low side (process

tube) and high side (filter-dier).

• Recover refrigerant.

References

RRRE

Page 32

Figure1

RRRE

Page 33

Figure 2

Figure 23: Placement of

recovery cylinder

Figure 24: Recovery with recovery

unit and cylinder

References

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Refrigerant recovery hand

pump with recovery cylinder

or bag

• Connect the recovery hand

pump outlet port to the

recovery cylinder or connection

port of the recovery bag.

• Connect the refrigeration

system (process tube and/or

filter-drier) to the inlet port of

the recovery hand pump.

Incorporate an inline filter-drier.

• Recover refrigerant.

Figure 25: Connecting recovery hand-pump

Figure 26: Recovery arrangement with hand-pump

RRRE

Page 35

Picture 5

RRRE

Page 36

Figure 6

References

RHC

Page 24

Figure 9

RRRE

Page 35

Figure 5

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Refrigerant recovery with

vacuum pump and recovery

bag

Step 1

Pressure equalizing

• The recovery bag is equipped

with a 1/4“ SAE male connection

port with valve core.

• Connect the recovery bag to

the piercing plier valve using a

refrigerant hose with ball valve

and core depressor. The ball

valve with core depressor is

placed at the recovery bag

connection port and the core

depressor opens the valve core

while connecting.

• Install the piercing plier or line

tap valve to the system and

open the valve.

• Refrigerant will be transferred

into the recovery bag.

• Close the valve (hose and

piercing device) after pressure

equalizing and remove the

refrigerant bag.

Figure 27: Connecting recovery bag

with piercing plier

References

RHC

Page 24

Figure 9

RRRE

Page 35

Picture 5

RRRE

Page 37

Figure 7

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Figure 28: Connecting recovery bag

with vacuum pump outlet

Step 2

Vacuum pump connection

• Connect the recovery bag to

the vacuum pump outlet

(exhaust port) using a refrigerant

hose with ball valve and

core depressor. The ball valve

with core depressor is placed

at the recovery bag connection

port and the core depressor

opens the valve core while

connecting.

• Mount the refrigerant hose of

the low pressure side of the

manifold set to the piercing

device and open the valve.

• Open the valves at the manifold

set (low pressure and

vacuum pump valve).

• Open the ball valve at the

recovery bag inlet.

• Start evacuation.

• Evacuate the system for

approximately 10 minutes.

There must not be any appreciable

overpressure in the

refrigerant bag, as this may

damage the vacuum pump!

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Chapter 13: Retrofit

Preface

With the phase-out of CFCs and HCFCs, existing refrigeration and air-conditioning equipment

operating with CFCs and HCFCs will ultimately need to be either replaced with new equipment

or retrofitted with alternative refrigerants.

Retrofit is the process by which the equipment currently using an ODS refrigerant is made to

run on a non-ODS refrigerant, without major effects on the performance of the equipment,

and without significant modifications/changes for the equipment, ensuring that existing

equipment operates until the end of its economic life.

Unlike a replacement, only some components of the existing system may need to be replaced.

Please refer to the tables ‘refrigerant data’ at the end of this chapter.

Involved changes

Typical retrofit may involve one or many of the following changes:

• Refrigerant

• Lubricant

• Desiccant filter (drier)

• Expansion valve

• Compressor (gearbox, speed, motor)

• Insulation and seal materials, elastomers

• For centrifugal chillers: purge systems, impeller/gearbox

Problems related to a CFC/HFC retrofit:

• Studies show from 1% less to 7% higher energy consumption than CFC-12.

• Problem of finding suitable lubricants: HFC-134a has very low solubility

and mineral oil does not mix well in HFC-134a.

• Poor oil returns back to the compressor, resulting in a possible

compressor failure.

• Fouling of expansion valves and heat exchanger surfaces, leading to

reduced system performance.

Retrofit in General

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Lubricants for alternative refrigerants:

• Polyol ester (POE) oils must be used with HFC refrigerants.

• Existing systems will require an oil flushing procedure because of

chemical incompatibilities between the refrigerants and lubricants.

• System charged with retrofit refrigerant can lead to early system

failure due to chemical reaction between the chlorine from CFC and

lubricating oils.

Polyol ester synthetic oils are backwards compatible.

Therefore, they are acceptable for use with CFC-12, HCFC-22 and CFC-502.

Important notes for the use of lubricants:

• POEs more than minerals tend to absorb water.

• Therefore, they need to be handled with care before being used

because of the increased water which may be present in the system.

• Proper evacuation is a must!

• A larger filter-drier may be required in a system which has been

retrofitted to POEs to make sure that all of the excess water is removed.

• POEs dissolve materials that CFCs or mineral oil does not. Therefore,

the filter-driers need to be frequently checked.

It is strongly recommended that the manufacturer-specified lubricant be used

to ensure that it is compatible with all the components with which it is in contact.

Residual mineral oil

Acceptable residual mineral oil content in a retrofitted system:

Evaporation temperature Residual mineral oil

in the system

Less than –15°C 1 to 3%

–15°C up to –5°C Approx. 5%

Above 0°C 5 to 10%

Table 1: Residual mineral oil content related to the evaporation temperature

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Retrofit categories

Drop-in retrofit:

A switch-over to an alternative refrigerant without any changes in the refrigeration system.

Some mineral lubricating oil may be required to be replaced by Polyol Ester (POE) /

Polyalkylene Glycol (PAG) after thorough flushing of the system using dry Nitrogen and

charging the required quantity of drop-in refrigerant.

Simple/economical retrofit:

A switch-over to an alternative refrigerant which only requires the change of a few incompatible

parts such as gaskets, o-rings, filter-drier. Simple retrofits may result in some cases

in slight decrease in either efficiency, capacity or both.

System optimisation or engineered retrofit:

A conversion to an alternative refrigerant which includes the replacement of major system

components, such as compressor, heat exchangers, expansion device etc. with new ones

that have been redesigned specifically for the alternative refrigerant.

Conclusions and statements

• It should be noted that properly working appliances are not recommended

for retrofit until there is a need to open the refrigeration system for repair.

• Properly operating systems could just be operating without any harm

to the ozone layer.

• For older RAC systems, it may be more cost-effective to replace rather

than retrofit. In addition, new equipment will be more energy-efficient.

• Retrofitting involves two kinds of costs:

- Cost of labour

- Cost of components that need to be changed

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• For cost calculation the problem of lubricant changing related to the

refrigerant choice may play a significant role. A refrigeration or air-conditioning

system with extensive pipe works and/or various amounts of evaporators

and accessories (e.g. oil separator or liquid accumulators) must be flushed

with the intended retrofit lubricant until certain remaining mineral oil

containment in the system is obtained.

• A good opportunity to carry out a retrofit procedure is in connection with

the regularly scheduled maintenance of a RAC system.

• The option of retrofitting will be considered in cases where the supply of CFCs

is getting scarce due to a ban on importation of CFC by the country, and

if no CFC is available at all.

Required data information collection:

1. Type of existing refrigerant

2. Type and brand names of all system components such as e.g. compressor

(condensing unit), evaporator, condenser …

3. Size of liquid receiver

4. Type and brand names of primary control devices

5. Type and brand names of secondary control devices

6. Dimensions and length of pipe work

7. Altitude difference between compressor, evaporator and condenser

8. Specific features of the existing equipment

9. Monitored system data under functional condition like evaporation and

condensing temperatures, electrical data, intended temperature of room

or conditioned medium

10. History of system failures (in particular compressor burn-out)

The Practical Retrofit Process

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Existing CFC

system retrofit

Isolate

compressor

Drain mineral

oil

Refill with

alternative oil

Fill alternative

refrigerant

Recover

CFC refrigerant

Refill with

alternative oil

Operate

system

Drain

oil

Check oil

contamination

If

< 5%

If

> 5%

Figure 1: Retrofit process flow

Refrigerant charging

Use HFC blends to remove liquid only from charging cylinder. Once liquid is removed from

the cylinder, the refrigerant can be charged to the system as liquid or vapour as desired.

Use the manifold gauges or a throttling valve to flash the liquid to vapour if required.

The refrigerant storage cylinder must be checked for leakage, otherwise the composition of

refrigerant can be altered. Refrigeration and AC systems should be clearly labelled after

conversion to avoid future mixing of refrigerants.

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• Charge the system with the alternative refrigerant.

Caution should be taken not to overcharge!

• 75% of the CFC charge as a starting point.

The optimum charge will vary depending on the system design and operating conditions,

but for most systems the best charge size will be 75-90% by weight of the original charge.

Start the system and let conditions stabilise. If the system is undercharged, add refrigerant

in small amounts (still removing liquid from the charging cylinder) until the system conditions

reach the desired level.

Attempting to charge until the sight glass is clear may result in overcharging

of refrigerant.

Various pressure switches may need to be adjusted to maintain proper operating conditions,

e.g.:

• Evaporator pressure regulators

• Cut-in and cut-out pressure switches

• Condenser fan cycling pressure switches

• Head pressure controls

• Crankcase pressure regulators

• Others

Due to the higher oil miscibility of HFCs and POE, verify proper compressor oil sump levels.

Check with the compressor manufacturer for proper amperage load ratings.

For data monitoring and evaluation use the ‘refrigeration system retrofit data sheet’ provided

at the end of the chapter.

Important notes:

Since all blends contain at least one flammable component, suitable measures should be

taken to avoid entry of air into the system. A critical displacement of the ignition point can

occur under high pressure when a high proportion of air is present. Besides this, pressure

tests with an air/refrigerant mixture are not allowed.

Do not use ‘shop-air’ for pressure tests!

Dry, oxygen-free Nitrogen should be used.

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Practical Issues

Oil change (drainage):

1. Check the system for leaks and

repair if necessary.

2. Separate compressor while using

pump down function or closing

the compressor’s shut-off valves.

3. If necessary recover remaining amounts

of refrigerant using an appropriate

refrigerant recovery technology.

4. Open the oil support connection

at the compressor’s crank-case.

5. Insert a 6 mm soft copper tube

reaching the crankcase bottom.

6. Seal the tapped hole with tape or

rubber seal and hold the copper tube.

7. Transfer a small amount of Nitrogen

with low pressure into the crankcase.

8. The oil will be transferred (pushed)

into a separate container.

9. Dispose of the oil (as contaminated

waste) in an environmentally friendly

way.

Figure 2: Oil change with dry Nitrogen

Dry Nitrogen

Compressor

6mm Copper tube

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Figure 3: Oil changing procedure

Figure 4: Oil support connection

• Nitrogen supply and oil draining

• Contaminated oil

• Example for oil support connection

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Figure 5: Oil drainage from hermetic compressor

Oil draining from a hermetic

compressor:

• Disassemble the compressor

• Turn compressor upside-down

• Drain the oil through suction

or process tube

• Refill small amount POE oil (150 ml)

and shake the compressor

• Drain the remaining oil

Oil change (refill):

1. Connect a vacuum pump to the suction

shut-off valve.

2. Insert the free end of the 6 mm copper

tube/hose assembly into a POE oil can

reaching the bottom.

3. Switch on the vacuum pump.

4. The oil will be transferred (pulled) due

to low pressure within the crankcase

into the compressor.

5. Observe the oil level in the compressor’s

sight glass but use the same volume as

removed within the draining process.

6. Stop oil flow.

7. Measure the charged amount of oil.

8. Evacuate the compressor.

9. Open the compressor’s stop-valves.

10. Run the compressor.

11. Check system for leaks.

Figure 6: Oil change with vacuum pump

Compressor

6 mm Copper tube

Oil sight glass

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Figure 7: Oil filling process (in detail)

Figure 8: Oil filling process

Due to the readiness of the fresh POE oil to absorb humidity, it is essential to use only small

cans of fresh oil. Do not store open cans of POE for further use.

Oil filling process (example 1)

• Vacuum pump connection to the

compressor’s suction line stop-valve

service port

• POE oil filling hose assembly

Oil filling process (example 2)

• Vacuum pump

• Hose assembly to crankcase

• Oil can with POE

• Weighing scale

• Recovery unit

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Table 2: Refrigeration system retrofit data sheet

Refrigeration System Retrofit Data Sheet

Service Company Name

Address

Telephone & Fax No.

Registration No.

Client Name

Address

Telephone & Fax No.

Contact Person Name

Installation/Appliance DATA

Type of Installation Manufacturer

Model and No. Serial No.

Type of Compressor Manufacturer

Model and No. Serial No.

Operating Data

Old New

Refrigerant Type Refrigerant Type

Refrigerant Charge Refrigerant Charge

Type of Lubricant Type of Lubricant

Lubricant Charge Lubricant Charge

Suction Pressure Suction Pressure

Discharge Pressure Discharge Pressure

Suction Line Temp. Suction Line Temp.

Discharge Line Temp. Discharge Line Temp.

Ambient Temperature Ambient Temperature

Room/Medium Temp. Room/Medium Temp.

LP Cut-Off LP Cut-Off

HP Cut-Off HP Cut-Off

Electrical Data

Power Supply (Voltage) Power Supply (Voltage)

Current Draw Compressor Current Draw Compressor

Other Installation Data

Discharge Line Diameter Discharge Line Length

Liquid Line Diameter Liquid Line Length

Suction Line Diameter Suction Line Length

Insulation Suction Line Altitude diff. Compr./Evap.

Type of Condenser Type of Evaporator

Type of Filter-Drier Type of Filter-Drier

Signature Technician Date Signature Client Date

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RETROFIT – Equipment Label

Company

Technician Name

Address

Telephone & Fax No.

Registration No.

Refitted to Refrigerant HFC-R134a

This system is only for the use with HFC-R134a

and synthetic lubricant

Refrigerant Charge

Lubricant Charge (old)

Lubricant Charge (new)

Retrofitted by:

Retrofit Date:

Signature:

Table 3: Retrofit equipment label data sheet

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CFCs (Phased out / Montreal Protocol)

Pure HCFC Refrigerants (Being phased out / Montreal Protocol)

Pure HFC Refrigerants (controlled under Kyoto Protocol)

Refrigerant Data

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HCFCs Blends (Being phased out / Montreal Protocol)

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HFC Blends (controlled under Kyoto Protocol)

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Hydrocarbons (local safety regulations apply)

Hydrocarbon Blends (local safety regulations apply)

Natural Refrigerants (local safety regulations apply)

Chapter 14: Safety

Preface

Work with or on refrigeration and AC equipment (RAC), machineries or material and substances

is always in different ways associated with high risks to personal health.

The following chapter gives an overview of important signs and work clothing concerning

the safety of personnel working in this field.

Work must only be performed by properly trained personnel equipped with safety equipment,

machineries and tools in good condition and of good quality.

Warnings

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Figure 1: Warning signs

Danger! Electricity

Danger! Hazard area

Danger! Suspended

heavy objects

Danger! Flammable

refrigerant

Danger! Inhalation

of harmful gases

Danger! Compressed

gas and vessel

Danger! Hot surfaces

Danger! Harmful skin/eye

contact with refrigerant and oil

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Bans

Rescue

Figure 2: Ban signs

Figure 3: Rescue signs

Smoking ban

Notice escape way Provide First Aid material

Only authorized persons

No bystanders

No open fire

Use of machineries not in

wet areas

Notice nearest Medical Help

contact information

Provide eye shower fluid

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Commandment

Wear suitable work clothes Wear protective gloves

Wear ear defender Wear safety glasses

Wear safety helmet Wear safety shoes

Plug out equipment for service Disconnect machineries for service

Figure 4: Commandment signs

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Protection grade depends on work task

Protection grade depends on work task

Work Clothing

Figure 5: Work gloves (example 1)

Figure 6: Work gloves (example 2)

Normal work gloves

with rubber knobs

Work gloves for refrigerant

and oil handling

Thick work gloves for

welding and brazing

Normal work gloves,

inside palm rubber covered

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Normal safety glasses

with side protection

Normal safety glasses

with full cover protection

Ear defender Respirator (dust and dirt) Safety helmet

Figure 7: Safety glasses

Figure 8: Safety devices

Protection grade depends on work task

Protection grade depends on work task

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Safety shoes (high and low shaft)

Overalls Normal work trousers Work jacket

Figure 10: Safety clothes

Figure 9: Safety shoes

Protection grade depends on work task

Protection grade depends on work task

Toe and heel protection (steel)

ANNEX

GLOSSARY

170

Glossary

Bending

Because a copper tube is so readily formable, it is often bent to adapt to the needs of a

piping system at the job site.This is a relatively simple matter to do by hand if a wide, sweeping

radius is involved, but for tighter bends, it is often desirable to use a special piece of

equipment to avoid kinking the line, which would restrict flow. Such tools can range from

a simple spring-like device that prevents the collapsing of tube walls, to more sophisticated

devices that involve lever or gear arrangements.

Brazing

Brazing is a joining process whereby a filler metal or alloy is heated to a melting temperature

above 450°C (840°F) and distributed between two or more close-fitting parts by capillary

action. At its liquid temperature, the molten filler metal and flux interact with a thin layer

of the base metal, cooling to form a strong, sealed joint. In order to attain the highest

strengths for brazed joints, parts must be closely fitted and the base metals must be exceptionally

clean and free of oxides.

Brazed joint: A joint obtained by the joining of metal parts with alloys which melt at temperatures

in general higher than 450°C, but less than the melting temperatures of the joined

parts.

Charging

This is transferring a refrigerant from the refrigerant source (refrigerant cylinder for virgin

refrigerants or recycled refrigerant cylinder) into a system, normally according to a specified

weight, a specified amount of subcooling or evaporating pressure. Charging is normally

carried out using a dedicated charging machine (e.g. in a production area) or using a cylinder

connected to the system via manifold/hoses. The cylinder is disconnected from the refrigeration

system after the refrigeration system has been completely charged with the new

refrigerant.

Containment

The application of service techniques or special equipment designed to preclude or reduce

loss of refrigerant from equipment during installation, operation, service or disposal of refrigeration

and air-conditioning equipment.

Evacuation

Evacuation of a refrigeration system means the ultimate removal of rests of moisture or noncondensable

gases in the system.This means the removal of all refrigerant and volatile contaminants

such as moisture and air, thus leaving a near-vacuum. Evacuation is normally carried

out by a specific vacuum pump, after refrigerant recovery has been completed (if applicable),

and is ideally drawn to an absolute pressure of 0.5 mbar (50 Pa, 375 micron) or lower.

ANNEX

GLOSSARY

171

Flared joint

Whereas brazing is a thermal bonding process, flared joints provide a mechanical connection

between copper tubing and fittings. This is a metal-to-metal compression joint in which a

conical spread is made on the end of the tube. This is a mechanical joint and is prone to

leakage.

Global Warming Potential

Global Warming Potential (GWP) is a measure of how much a given mass of greenhouse

gas is estimated to contribute to global warming. It is a relative scale which compares the

contribution to global warming of the gas in question to that of the same mass of Carbon

Dioxide (whose GWP is by definition 1) over a defined time horizon. For instance, Methane is

a significant contributor to the greenhouse effect and has a GWP of 21 (100-yr time horizon).

This means Methane is approximately 21 times more heat-absorptive than Carbon Dioxide

per unit of weight.

GTZ (Deutsche Gesellschaft für Technische Zusammenarbeit GmbH/German

Technical Cooperation Agency)

As an international cooperation enterprise for sustainable development with worldwide operations,

the federally owned ‘Deutsche Gesellschaft für Technische Zusammenarbeit’ (GTZ)

GmbH supports the German government in achieving its development policy objectives. It

provides viable, forward-looking solutions for political, economic, ecological and social development

in a globalised world.Working under difficult conditions, GTZ promotes complex

reforms and change processes. Its corporate objective is to improve people’s living conditions

on a sustainable basis.

Hermetisation

Hermetisation is to maintain a ‘sealed system’ of the refrigerant cycle in refrigeration. A

sealed system is a refrigeration system in which all refrigerant containing parts are made

tight by welding, brazing or a similar permanent connection.

MLF (Multilateral Fund) of the Montreal Protocol

The Multilateral Fund was established in 1990 as a financial mechanism for the implementation

of the Montreal Protocol. By financing technology transfer and cooperation, the Fund

assists developing (so called Article-5) countries to meet their commitments under the

Montreal Protocol, that means to enable these countries to phase out and replace ODS within

an agreed time frame. Industrialised countries agreed to contribute to the Fund in order to

help Article-5 countries achieve the Protocol’s goals. Financial and technical assistance (closure

of ODS production plants and industrial conversion, technical assistance, information

dissemination, training and capacity building) is provided in the form of grants or concessional

loans and is delivered primarily through four implementing agencies (UNEP, UNDP,

UNIDO,World Bank).

ANNEX

GLOSSARY

172

Montreal Protocol

The international treaty ‘Montreal Protocol on Substances that Deplete the Ozone Layer’

was agreed in 1987 after scientists discovered that certain man-made substances, such as

CFCs, were contributing to the depletion of the Earth’s ozone layer.The ozone layer protects

life below from harmful UV radiation. So far it has been ratified by all countries worldwide

(November 2009 – universal ratification). The Protocol aims at protecting the ozone layer

and therefore regulates the successive phase-out of substances that could harm the ozone

layer through the restriction of production, import und use of such substances according

to a specific timetable. The phase-out of ODS will enable the ozone layer to repair itself.

Natural Refrigerants

Natural refrigerants are naturally occurring substances, such as Hydrocarbons (e.g. Propane,

Iso-Butane), Carbon Dioxide and Ammonia.These substances can be used (amongst others)

as refrigerants in various kinds of refrigeration and air-conditioning systems. The key characteristics

of these refrigerants are that they don’t contribute to depletion of the ozone layer

and have no or only a negligible global warming impact.

ODS (Ozone-Depleting Substances)

These are substances that damage the ozone layer in the upper atmosphere.They are widely

used in refrigerators, air-conditioners, foam extrusion, fire extinguishers, dry cleaning,

industrial cleaning, as solvents for cleaning, electronic equipment and as agricultural fumigants.

They are defined in Annex A of the Montreal Protocol. Ozone-depleting substances

include:

• Chlorofluorocarbons (CFCs),

• Halon,

• Carbon Tetrachloride, Methyl Chloroform,

• Hydrobromofluorocarbons (HBFCs),

• Hydrochlorofluorocarbons (HCFCs),

• Refrigerant blends containing HCFCs,

• Methyl Bromide,

• Bromochloromethane (BCM).

ODP (Ozone Depletion Potential)

This is a relative value that indicates the potential of a substance to destroy ozone gas (and

thereby damage the Earth’s ozone layer) as compared with the impact of a similar mass of

chlorofluorocarbon-11 (CFC-11), which is assigned a reference value of 1.Thus, for example,

a substance with an ODP of 2 is twice as harmful as CFC-11.

ANNEX

GLOSSARY

173

OFP (Overfill Protection)

Overfill protection is a device (switch) installed to a refrigerant recovery unit and recovery

cylinder originally intended to be a safety feature whilst transferring and storing refrigerants

into a cylinder. On most machines, these switches simply turn off the recovery machine.

OFP devices do not provide any recovery machine with a ‘walk away’ feature. Any refrigerant

transfer into systems or special cylinders must be monitored by measuring the weight of the

refrigerant by the technician. Due to specific circumstances hazards can occur in following

situations:

1. During push-pull procedures, once a siphon is started, merely powering

off the recovery machine does not prevent the recovery cylinder from

overfilling.

2. When using a cylinder with a large amount of cold refrigerant and

recovering from a system at higher temperature, turning the recovery

machine off will not stop the refrigerant from migration to the coldest

point (in this case the recovery cylinder) eventually overfilling the tank

even when the machine is off.

Phase-Out of Ozone-Depleting Substances

In this context, phase-out means a successive limitation and production ban on substances

that deplete the ozone layer according to a defined schedule for different groups of countries

as regulated under the Montreal Protocol.

Pressing

Pressing means a method of producing hermetically sealed metal-to-metal tube connections

with the use of specific connectors, adapters and tools.

Reclamation

Reclamation is the (re-)processing of used refrigerants through mechanisms such as filtering,

drying, distillation and chemical treatment to new product specifications. Note that

chemical analysis of the refrigerant determines if appropriate specifications have been met.

The identification of contaminants and required chemical analysis are both specified in

national and international standards for new product specifications.

Recovery

Recovery means removing a refrigerant in any condition from a refrigeration system and

storing it in an external container.

ANNEX

GLOSSARY

174

Recycling

This is the process of reducing contaminants in used refrigerants by separating oil, removing

non-condensables and using devices such as filters, driers or filter-driers to reduce moisture,

acidity and particulate matter. The aim of recycling is to reuse the recovered refrigerant

following a basic cleaning process such as filtering and drying.

Refrigerant

A fluid used for heat transfer in a refrigerating system which absorbs heat at a low temperature

and a low pressure and rejects heat at a higher temperature and a higher pressure

usually involving changes of the state of the fluid.

Retrofit

This is where refrigeration equipment is subject to some modifications (upgrading or

adjustment) so that it can be used with a refrigerant different to the original one. This may

involve, for example, oil change, swapping of certain system components or modifications

to electrical devices.

SAE (Society of Automotive Engineers)

SAE is an international non-profit organisation with more than 90,000 members (engineers,

students, business executives, educators etc.) from all over the world who share information

and exchange ideas for advancing the engineering of mobility systems.

TÜV (Technischer Überwachungs-Verein)

TÜV is a German testing and certification organisation. Its services comprise consultancy,

testing, certification and training mainly in the field of engineering.

ANNEX

ACRONYMS AND ABBREVIATIONS

175

Acronyms and Abbreviations

AC Air-Conditioning

AC Alternating Current

BCM Bromochloromethane

CFC Chlorofluorocarbon

CFM Cubic Feet per Minute

CO2 Carbon Dioxide

CP Copper Phosphorus

CPR Constant Pressure Regulator

DC Direct Current

DOT Department of Transportation

(USA)

EN European Norm

EU European Union

GTZ Gesellschaft für Technische

Zusammenarbeit GmbH

(German Technical

Cooperation Agency)

GWP Global Warming Potential

HC Hydrocarbon

HBFC Hydrobromofluorocarbon

HCFC Hydrochlorofluorocarbon

HFC Hydrofluorocarbon

HP High Pressure

LP Low Pressure

MAC Mobile Air-Conditioning

MI Measuring Instruments

MLF Multilateral Fund (of the

Montreal Protocol)

MMA Ministério do Meio Ambiente

do Brazil

NCG Non-Condensable Gas

NPT National Pipe Thread

OD Outside Diameter

ODP Ozone Depletion Potential

ODS Ozone-Depleting Substances

OFP Overfill Protection

PAG Polyalkylene Glycol

POE Polyol Ester

PVC Poly Vinyl Chloride

RAC Refrigeration and Air-

Conditioning

RHC Refrigerant Handling and

Containment

R&R Recovery & Recycling

RRRE Recovery, Recycling,

Reclamation and Evacuation

RTK Retrofit Test Kit

SAE Society of Automotive Engineers

SENAI Brazilian ‘Servico Nacional de

Aprendizagem Industrial’

TEV Thermostatic Expansion Valve

TT Tubing Tools

TÜV Technischer Überwachungs-

Verein (German testing and

certification organisation)

UNF Unified Fine Thread

US United States

UV Ultra Violet

ANNEX

INDEX

176

Index

----------A----------

AC, see Air-Conditioning

AC, see Alternating Current

Acetylene 13

Acid 29, 130, 139, 140, 141

Air-Conditioning (AC) 1, 2, 3, 18, 32, 33, 43, 49,

50, 53, 81, 82, 102, 121, 142, 148, 151, 152,

164, 170, 172

- Mobile Air-Conditioning (MAC) 26, 34, 121,

140, 142

Alternating Current (AC) 50

Aluminium 5, 7, 19, 104, 121, 122, 125

Ammonia 1, 172

Anaerobic Liquid 124, 127

Anemometer 49

Atmosphere 2, 85, 110, 117, 132, 172

----------B----------

BCM, see Bromochloromethane

Bender 11, 77

Bending 53, 67, 68, 77, 78, 79, 80, 128, 170

Blend 44, 152, 153, 161, 162, 163, 172

Blowing Agent 2

Brass 5, 7, 13, 14, 15, 18, 19, 59, 66, 87, 88, 121,

122, 125, 126

Brazil 1

Brazilian ‘Servico Nacional de Aprendizagem

Industrial’ (SENAI) 1

Brazing 1, 10, 13, 14, 15, 53, 63, 67, 68, 81, 82,

83, 84, 85, 86, 87, 88, 89, 90, 100, 102, 105,

167, 170, 171

Bromochloromethane (BCM) 172

Burner 13

----------C----------

Calibration Screw 18, 21

Carbon Dioxide (CO2) 1, 171, 172

Carbon Tetrachloride 172

Capacitor 49, 61

Capacity Test 41, 100, 114

CFC, see Chlorofluorocarbon

Charging 19, 24, 25, 34, 38, 39, 40, 41, 46, 51,

72, 73, 74, 98, 102, 103, 108, 117, 118, 119,

120, 142, 143, 150, 152, 153, 170

- Scale 25, 38, 39, 46, 72, 104

Chiller 148

Chlorine 149

Chlorofluorocarbon (CFC) 1, 2, 32, 35, 36, 40,

44, 63, 104, 132, 136, 148, 149, 151, 152,

153, 160, 172

Clamp 9, 11, 48, 92

Cleaner 14

CO2, see Carbon Dioxide

Compression Cone 92

Compressor 40, 41, 48, 51, 58, 60, 61, 69, 72,

73, 76, 81, 95, 98, 100, 101, 104, 106, 108,

109, 114, 115, 117, 119, 128, 135, 136, 138,

139, 140, 142, 148, 150, 151, 152, 153, 154,

156, 157, 158

Condenser 32, 60, 61, 76, 95, 96, 99, 100, 101,

106, 114, 115, 140, 151, 158

Condensing 76

- Temperature 151

- Unit 58, 62, 65, 151

Connector 10, 25, 121, 122, 123, 125, 126, 127,

128, 173

Constant Pressure Regulator (CPR) 140

Containment 1, 18, 99, 129, 151, 170

Contaminant 28, 140, 170, 173, 174

Contamination 55, 69, 130, 138, 139, 141, 152

- Test Kit 28

Control 41, 67, 153

- Board 35

- Device 74, 120, 151

Conversion 150, 152, 171

Cooling Agent, see Refrigerant

Copper 5, 6, 7, 8, 10, 12, 13, 14, 15, 55, 56, 57,

59, 67, 68, 77, 78, 79, 80, 81, 82, 87, 88, 89,

90, 93, 94, 102, 122, 154, 156, 170, 171

- Phosphorus (CP) 81

Core 8, 24, 59, 66, 146, 147

- Depressor 22, 23, 146, 147

- Removal 23, 24

Coupler 9, 23, 26, 34, 51, 103, 116, 118, 128,

142

Coupling 59, 122, 123

CP, see Copper Phosphorus

CPR, see Constant Pressure Regulator

Crankcase 153, 154, 156, 157

Cylinder 15, 16, 19, 25, 27, 32, 34, 38, 39, 40,

42, 45, 46, 70, 72, 73, 101, 103, 104, 110,115,

116, 118, 129, 130, 131, 132, 133, 134, 136,

137, 138, 139, 140, 144, 145, 152, 170, 173

----------D----------

DC, see Direct Current

Deburrer 6, 83, 91

Department of Transportation (USA) (DOT) 27, 132

Direct Current (DC) 50

DOT, see Department of Transportation (USA)

Drainage 33, 39, 154, 156

ANNEX

INDEX

177

----------E----------

Elastomer 148

Evacuation 1, 18, 32, 71, 72, 103, 112, 117, 118,

142, 147, 149, 170

- Unit 34, 38

Evaporation 149, 151

Evaporator 58, 59, 60, 61, 62, 65, 66, 69, 72, 74,

76, 95, 96, 101, 106, 107, 115, 120, 151, 153,

158

----------F----------

Filter 37, 44, 76, 100, 102, 115, 133, 134, 140,

141, 174

- Drier 32, 33, 36, 58, 59, 60, 63, 67, 76, 95,

99, 100, 101, 102, 106, 109, 110, 111, 114,

115, 117, 119, 126, 142, 144, 145, 148, 149,

150, 158, 174

Flare 8, 15, 19, 22, 23, 26, 63, 71, 92, 93, 94

- Nut 66, 67, 74, 92, 93, 94, 120

Flaring 1, 11, 53, 63, 67, 68, 90, 91, 92, 93

Flux 81, 87, 102, 170

Freezer 47, 95, 96, 102, 106, 107, 117

Fridge 96, 106, 107

----------G----------

Gasket 22, 25, 96, 107, 150

Gas 16, 37, 39, 40, 69, 70, 71, 76, 81, 94, 103,

104, 108, 109, 116, 129, 131, 140, 164, 170,

171, 172

- Pressure 3

- Recovery 99, 136

- Regulator 13

Gauge 18, 19, 20, 21, 33, 36, 38, 70, 71, 72, 73,

74, 116, 117, 119, 120, 142, 144, 152

- Connection 98, 108

- Pressure Gauge 18, 20, 21, 32, 34, 35, 38,

39, 51, 70

- Vacuum Gauge 18, 20, 21, 37, 38, 45, 71,

72, 117, 118, 119

Global Warming 104, 171, 172

Global Warming Potential (GWP) 1, 171

Greenhouse 171

GWP, see Global Warming Potential

----------H----------

Halon 172

HBFC, see Hydrobromofluorocarbon

HC, see Hydrocarbon

HCFC, see Hydrochlorofluorocarbon

Heat 81, 86, 87, 88, 96, 102, 105, 106,

107, 171, 174

- Exchanger 148, 150

- Transfer 95, 96, 106, 174

Heating 82, 86

- Belt 28

- Device 34

Hermetisation 69, 171

HFC, see Hydrofluorocarbon

Hydrobromofluorocarbon (HBFC) 172

Hydrocarbon (HC) 1, 8, 20, 38, 39, 42, 44, 53,

104, 105, 111, 118, 121, 163, 172

Hydrochlorofluorocarbon (HCFC) 1, 2, 40, 44, 45,

63, 136, 148, 149, 160, 161, 172

Hydrofluorocarbon (HFC) 1, 26, 35, 36, 38, 44,

58, 62, 63, 104, 148, 149, 152, 153, 159, 160

----------I----------

Inspection 10, 93

- Mirror 10, 102

Installation 25, 27, 55, 66, 68, 76, 143, 158, 170

Iso-Butane 42, 172

----------L----------

Leak 8, 25, 41, 43, 55, 69, 70, 71, 74, 90, 95, 102,

105, 106, 116, 117, 120, 128, 154, 156

- Detection/detector 3, 41, 42, 43, 74, 120

- Test 70, 71, 74, 105, 116, 117, 120, 142

Leakage 102, 117, 152, 171

Lighter 14, 85

Line 27, 76, 135, 143, 146, 158, 170

- Liquid Line 68, 69, 76, 158

- Suction Line 66, 68, 69, 76, 80, 139, 157, 158

- Vent Line 109, 110, 111, 112, 113, 114

Liquid 25, 27, 30, 36, 39, 58, 59, 60, 68, 69, 72,

73, 76, 117, 124, 127, 129, 130, 131, 133, 135,

136, 137, 144, 151, 152, 153, 158, 170

Locking Ring 123, 127, 128

Lubricant 29, 30, 40, 76, 81, 101, 115, 138, 148,

149, 151, 158, 159

- Charge 76, 158, 159

----------M---------

MAC, see Mobile Air-Conditioning

Manifold 19, 73, 118, 147, 152, 170

- Gauge Set 20, 33, 38, 70, 72, 116, 144

- Service Gauge 18, 19, 20, 21

Methacrylic Ester 124

Methane 42, 171

Methyl Bromide 172

Methyl Chloroform 172

‘Ministério do Meio Ambiente do Brazil’ (MMA) 1

MLF, see Multilateral Fund of the

Montreal Protocol

MMA, see ‘Ministério do Meio Ambiente do Brazil’

Moisture 55, 64, 69, 97, 108, 130, 139, 140,

141, 170, 174

ANNEX

INDEX

178

Montreal Protocol 2, 160, 161, 171, 172, 173

Motor 61, 109, 148

Multilateral Fund of the Montreal Protocol

(MLF) 171

----------N----------

Nitrogen 15, 51, 70, 71, 81, 82, 85, 89, 101,

103, 105, 110, 112, 115, 116, 117, 128, 150,

153, 154

- Blowing Process 113

- Flow 85, 87, 101, 115

- Supply 115, 116, 155

----------O----------

ODP, see Ozone Depletion Potential

ODS, see Ozone-Depleting Substances

OFP, see Overfill Protection

Oil 28, 29, 30, 31, 32, 33, 37, 58, 93, 109, 130,

135, 137, 138, 139, 140, 148, 149, 150, 151,

152, 153, 154, 155, 156, 157, 164, 167, 174

- Change 154, 155, 156, 174

- Filling Process 157

- Flushing Procedure 149

- Separator 33, 140

- Test 28, 29, 138, 139

Operation 18, 30, 61, 69, 71, 73, 80, 170, 171

Overfill Protection (OFP) 27, 32, 34, 46, 133, 134,

173

Overload Protection 61

Oxide 81, 85, 170

- Formation 85, 89

Oxygen 13, 70, 81, 129, 153

Ozone 1, 2, 172

- Depleting Substances (ODS) 2, 172, 173

- Depletion Potential (ODP) 172

- Layer 2, 150, 172, 173

----------P----------

PAG, see Polyalkylene Glycol

Phase-Out 1, 2, 148, 172, 173

Pipe 10, 35, 39, 55, 56, 58, 59, 60, 68, 74, 80, 81,

84, 93, 98, 101, 115, 117, 119, 120

- Work 53, 55, 58, 68, 85, 90, 151

Plier 119

- Piercing Plier 8, 35, 98, 99, 100, 108, 109,

111, 112, 135, 143, 146

- Pinch-off Plier 7, 119

POE, see Polyol Ester

Polyalkylene Glycol (PAG) 150

Polyol Ester (POE) 29, 30, 149, 150

Poly Vinyl Chloride (PVC) 40

Port 23, 36, 69, 70, 72, 73, 102, 110, 111, 112,

116, 137, 142, 144, 145, 146, 147, 157

Pressing 53, 115, 119, 121, 127, 173

Pressure 3, 9, 18, 19, 20, 21, 26, 32, 33, 34, 35,

36, 38, 39, 51, 55, 58, 59, 61, 63, 64, 67, 70, 71,

74, 75, 76, 80, 85, 98, 99, 102, 103, 108, 112,

113, 116, 117, 118, 120, 121, 124, 128, 130,

131, 136, 137, 138, 142, 143, 146, 147, 153,

154, 156, 158, 170, 174

- Control 67, 153

- Regulator 13, 15, 71, 101, 103, 104, 110,

112, 115, 135, 140, 153

- Switch 61, 64, 67, 68, 73, 153

Probe 41, 42, 47

Propane 13, 42, 172

Pump 19, 31, 36, 37, 38, 41, 43, 61, 71, 72, 110

111, 112, 114, 117, 118, 135, 137, 144, 145,

146, 147, 154, 156, 157, 170

PVC, see Poly Vinyl Chloride

----------R----------

Radiation 2, 172

RAC, see Refrigeration and Air-Conditioning

Reclamation 1, 32, 173

Recovery 1, 27, 32, 33, 34, 35, 36, 99, 111, 130,

132, 133, 134, 135, 136, 137, 138, 140, 142,

143, 144, 145, 146, 147, 154, 173

- Unit 19, 32, 33, 133, 134, 135, 136, 137, 140,

144, 157, 170, 173

Recycling 1, 3, 32, 33, 34, 99, 129, 141, 142, 174

- Unit 33, 140, 141

Refrigerant 1, 2, 3, 8, 9, 18, 20, 22, 24, 25, 27, 28,

32, 33, 34, 35, 36, 38, 39, 40, 41, 42, 43, 44, 45,

46, 51, 53, 55, 58, 60, 61, 62, 63, 64, 67, 72, 73,

74, 76, 81, 85, 95, 98, 99, 104, 105, 106, 108,

109, 110, 111, 118, 119, 121, 129, 130, 131,

132, 134, 135, 136, 137, 138, 139, 140, 143,

144, 145, 146, 147, 148, 149, 150, 151, 152,

153, 154, 158, 159, 160, 163, 164, 167, 170,

172, 173, 174

- Charge 76, 102, 136, 142, 158, 159

- Cycle 43, 95, 97, 98, 99, 102, 103, 106, 108,

114, 116, 118, 143, 171

- Emission 22, 23

- Flow 19, 20, 60, 105, 135, 141

- Handling and Containment (RHC) 1, 18

- Natural 1, 172

- Transfer 18, 22, 36, 173

Refrigeration and Air-Conditioning (RAC) 1, 2, 3,

32, 33, 53, 81, 82, 148, 150, 151, 164, 170, 172

Refrigeration 1, 3, 18, 30, 32, 33, 50, 55, 58, 62, 65,

81, 104, 121, 124, 143, 148, 164, 170, 171, 174

- Cycle 69, 104

- Sector 1, 2, 82

- System 1, 3, 30, 32, 41, 43, 45, 46, 53, 55, 58,

ANNEX

INDEX

179

60, 65, 66, 69, 70, 71, 72, 81, 95, 112, 136, 138,

140, 145, 150, 151, 152, 153, 158, 170, 171,

172, 173

Refrigerator 47, 95, 96, 102, 117, 143, 144, 172

Retrofit 1, 30, 148, 149, 150, 151, 152, 153, 158,

159, 174

- Test Kit (RTK) 30

RHC, see Refrigerant Handling and Containment

RTK, see Retrofit Test Kit

----------S----------

SAE, see Society of Automotive Engineers

Safety 16, 27, 51, 74, 77, 82, 90, 100, 104, 105,

124, 129, 130, 134, 138, 163, 164, 166, 168,

169, 173

Scale 18, 38, 72, 73, 81, 85, 118, 134, 144, 171

- Charging Scale 25, 38, 39, 46, 104

- Pressure Scale 18, 21

- Weighing Scale 134, 157

SENAI, see Brazilian ‘Servico Nacional de

Aprendizagem Industrial’ 1

Sight Glass 19, 20, 33, 37, 58, 59, 60, 64, 67,

153, 156

Siphon 138, 173

Society of Automotive Engineers (SAE) 8, 15, 19,

22, 23, 25, 31, 36, 40, 59, 63, 64, 146, 174

Solder 8, 15, 86, 89, 102

Soldering 81, 90

Strainer 58

Sustainable Development 171

System 1, 3, 10, 18, 25, 30, 32, 41, 43, 45, 46,

49, 53, 55, 58, 60, 62, 65, 69, 70, 71, 72, 73,

74, 80, 81, 85, 90, 95, 97, 99, 101, 102, 103,

104, 105, 108, 110, 112, 115, 116, 117, 118,

119, 120, 121, 128, 132, 135, 136, 137, 138,

139, 140, 142, 143, 144, 145, 146, 147, 148,

149, 150, 151, 152, 153, 154, 156, 158, 159,

170, 171, 172, 173, 174

- Cycle 95, 97, 98, 106, 108

- Failure 149, 151

Switch 27, 61, 97, 107, 133, 134, 138, 150, 173

- Master Switch 59, 65, 68

- Pressure Switch 59, 61, 64, 67, 68, 73, 76, 153

----------T----------

Technischer Überwachungs-Verein

(TÜV, German testing and certification

organisation) 132, 174

Temperature 3, 18, 28, 35, 39, 49, 58, 64, 66,

74, 75, 81, 88, 95, 96, 97, 98, 102, 106, 107,

108, 120, 121, 130, 138, 149, 151, 158, 170,

173, 174

Tester 50, 51

TEV, see Thermostatic Expansion Valve

Thermometer 38, 39, 47, 49, 96, 97, 107

Thermostat 28, 58, 61, 64, 68, 97, 107

Thermostatic Expansion Valve (TEV) 60, 63, 140

Torch 13, 85, 86, 100, 102

Tube 5, 7, 8, 9, 11, 12, 27, 55, 67, 68, 77, 78, 79,

81, 82, 83, 84, 85, 86, 87, 90, 91, 92, 93, 94,

98, 99, 100, 108, 114, 115, 117, 121, 122,

123, 124, 125, 126, 127, 128, 143, 154, 156,

170, 171

- Capillary Tube 5, 10, 58, 60, 64, 66, 99, 101,

102, 104, 114, 115

- Connection 10, 121, 122, 123, 124, 127,

173

- Cutter 5, 99, 114

- Process Tube 98, 101, 102, 108, 117, 119,

143, 144, 145, 156

TÜV, see Technischer Überwachungs-Verein

(German testing and certification organisation)

----------U----------

Ultra Violet (UV) 2, 43, 172

UNF, see Unified Fine Thread

Unified Fine Thread (UNF) 59

United States (US) 27, 56, 57

US, see United States

UV, see Ultra Violet

----------V----------

Vacuum 18, 19, 20, 21, 22, 37, 38, 41, 45, 71,

72, 109, 110, 111, 112, 114, 117, 118, 119,

124, 144, 146, 147, 156, 157, 170

Valve 8, 16, 19, 20, 21, 22, 23, 24, 25, 27, 32,

33, 37, 39, 40, 42, 59, 66, 101, 110, 112, 115,

116, 117, 118, 119, 131, 135, 137, 140, 143,

146, 147, 152, 156, 157

- Ball Valve 22, 36, 146, 147

- Expansion Valve 58, 59, 60, 63, 66, 90, 140,

148

- Safety Valve 16, 27, 51

- Schrader Valve 8, 24, 102

- Service Valve 8, 26, 74, 102, 120, 135, 142,

143

- Shut-off Valve 60, 138, 154, 156

- Solenoid Valve 37, 58, 59, 60, 61, 63, 67

Ventilator 32, 62

Voltage 48, 50, 62, 76, 129, 158

----------W----------

Welding 167, 171

Deutsche Gesellschaft für

Technische Zusammenarbeit (GTZ) GmbH

– German Technical Cooperation –

Programme Proklima

Dag-Hammarskjöld-Weg 1–5

65760 Eschborn, Germany

T +49 61 96 79-10 22

F +49 61 96 79-80 10 22

E proklima@gtz.de

I www.gtz.de/proklima

The manual GOOD PRACTICES IN REFRIGERATION is the second edition of a booklet

jointly published by the PROKLIMA Programme of the Deutsche Gesellschaft für

Technische Zusammenarbeit (GTZ) GmbH, the ‘Brazilian Servico Nacional de

Aprendizagem Industrial’ (SENAI) and the ‘Ministerio do Meio Ambiente do

Brazil’ (MMA) in 2004.

This manual has now been updated to provide professional guidance on how to

service and maintain refrigeration systems operating with new technology, e.g.

ozone- and climate-friendly alternative refrigerants to CFCs and HCFCs.

It addresses essential know-how on containment of HFC refrigerants which

have a high Global Warming Potential (GWP) and provides information on the

safe use of environmental-friendly natural refrigerants, such as CO2, Ammonia

or Hydrocarbons.