Table Of Contents - HVAC Education Australia

Transcription

UEENEEJ102A Prepare and connect refrigerant tubing and fittings
Table of Contents
Copyright………………………………………………………………………………………….. 2
UEENEEJ102A Unit descriptor and student information
……………….…. 7
UEENEEJ102A Knowledge and Skills KS01-EJ102A …………………………….….
13
Chapter 1
Piping………………………………………………………………..………….. 15
Chapter 2
Cutting……………………………………………………………………..…….. 27
Chapter 3
Bending………………………………………………………………………….. 32
Chapter 4
Joining………………………………………………………………………….. 38
Chapter 5
Soldering and Brazing Equipment…………………………………………..
Chapter 6
Silver Solder………………… ……………………..………………………….. 67
Chapter 7
Soldering Techniques
UEENEEJ102A Student Workbook V 1.0
th
Date: 6 August 2011
…………………..…………………………..
53
73
Page 1 of 76
This page intentionally left blank
th
Date: 6 August 2011
Page 2 of 76
UEENEEJ102A
Prepare and connect refrigerant tubing and
fittings
Unit Description
This unit covers the basic connection of refrigeration and air conditioning piping/tubing and
fittings. It encompasses the safe use of hand, fixed and portable power tools for cutting, flaring,
bending, swaging, silver brazing copper tube to copper tube, bundy tube and brass and steel
fittings, measurement and reading drawings and diagrams.
Overview
This guide has been developed to support training for the Refrigeration and Air Conditioning
industry in the UEENEEJ102A Prepare and connect refrigerant tubing and fittings unit of
competency
Content covered
This unit of competency is designed to „prepare refrigerant tubing and fittings including:

Applying tubing and fitting appropriately to equipment drawings or diagrams,

Using established methods to cut, flare, bend, swage and silver brazing copper tube,

Attaching fittings correctly to industry standards,

Conducting component routine quality checks, and

Dealing with unplanned events by drawing on essential knowledge and skills to provide
appropriate solutions incorporated in the holistic assessment with the above listed items.
Relationship to competency standards
This competency develops underpinning knowledge which is relevant to skills developed at
Level THREE (3) of the UEE07 aligned directly to the Australian Qualifications Framework
(AQF).
Elements of competency
To successfully complete this unit of competency, you must demonstrate competence in the
following elements and performance criteria:
th
Date: 6 August 2011
Page 3 of 76
ELEMENT
6) Elements describe the essential
outcomes of a unit
1
Prepare to fabricate tubing and
attach fittings for refrigeration
and/or air conditioning systems
PERFORMANCE CRITERIA
Performance criteria describe the required
performance needed to demonstrate
achievement of the element. Assessment of
performance is to be consistent with the
evidence guide.
1.1
OHS procedures for a given work area are
identified, obtained and understood through
established routines and procedures
1.2
Established OHS risk control measures and
procedures are followed in preparation for the
work.
Safety hazards which have not previously
been identified are reported and advice on
risk control measures is sought from the work
supervisor.
The nature of work is obtained from
documentation or from work supervisor to
establish the scope of work to be undertaken.
Advice is sought from the work supervisor to
ensure the work is coordinated effectively with
others.
Sources of materials that may be required for
the work are accessed in accordance with
established routines and procedures.
Tools, equipment and testing devices needed
to carry out the work are obtained and
checked for correct operation and safety
Established OHS risk control measures and
procedures for carrying out the work are
followed.
1.3
1.4
1.5
1.6
1.7
2
Fabricate tubing and attach
fittings for refrigeration
and/or air conditioning
systems
2.1
2.2
2.5
2.6
th
Date: 6 August 2011
Work in strict accordance with OHS
requirements and when necessary conducted
within established safety procedures
2.3
Established methods used to cut, flare,
swage, bend, silver braze tubing and fittings
as they apply to the refrigeration/air
conditioning equipment arrangements.
2.4
Refrigerant tubing and fittings are silver
brazed with the use of dry nitrogen to prevent
contamination.
Fabricate tubing and attach fittings are prepared
efficiently without waste of materials or
damage/contamination to apparatus and the
surrounding environment or services and using
sustainable energy practices.
Routine quality checks are carried out in accordance
with work instructions/or specifications including
dimensions and pressure testing.
Page 4 of 76
3
Complete work and
report
3.1
OHS work completion risk control measures and
procedures are followed.
3.2
Work site is cleaned and made safe in accordance
with established procedures.
3.3
Work supervisor is notified of the completion of the
working accordance with established procedures.
Resources / Reference Materials for this Unit
Unit materials
To undertake study in this unit, you will need:
Essential textbooks
1.Australian Refrigeration and Air Conditioning 4 th Edition
2.
Recommended texts
1. Principles of Refrigeration (5th Edition) Roy J. Dossat & Thomas J. Horan
2. Electrical Principles for the Electrical Trades (6th Edition) Jim Jenneson &
Bob Harper
3. Modern Refrigeration and Air Conditioning Andrew D. Althouse, & A.F.
Bracciano
4. Mathematics for Technicians.(6th Edition) Blair Alldis.
Other materials
Safety glasses, steel cap boots, long sleeve shirts.
E-Learning Activities
Go to www.hvaceducation.wikispaces.com
Visit the UEENEEJ002B/J102A page
Learning exercises
1.Review questions at the end of each chapter.
Workshop/practical activities
1.
2.
3.
4.
5.
6.
Piping
Bending
Cutting
Joining
Brazing
Practical Project.
th
Date: 6 August 2011
Page 5 of 76
Materials supplied by SkillsTech Australia
All copper components, brazing materials and hand tools supplied.
Assessment
Your knowledge and skills will be assessed through competency tests which will measure how
well you meet the performance criteria for this unit.
Assessment
Questioning
Practical
demonstration
Assessment Method
Written assessment and verbal
examination under supervised conditions.
1.
2.
3.
4.
5.
Practical task 1 – Risk assessment
Practical task 2 - Cutting, Bending
Practical task 3 - Flaring & Swaging
Practical task 4 Brazing
Practical Project – final assessment
What it covers
Theory component. Required
knowledge for the elements and
performance criteria of this unit.
Observation of you performing a
given practical task. How you apply
skills and knowledge to meet the
elements and performance criteria
of this unit.
NB: Training Record / Log Books are not used for assessment. Activities must be recorded on
your e-profiling.
Critical aspects of evidence – Employability Skills
Students must demonstrate competence in all assessment items to be deemed
competent in a Unit of Competency.
Resources to be supplied by student
To complete this unit of competency you will need:
 Handouts – class and private study
 Completed practical assessment sheet
 Appropriate PPE
General information
Progress of study
You are expected to achieve satisfactory progress in your studies. If you are having
difficulty maintaining acceptable progress, please discuss with your teacher and/or the
Institute Counsellor as soon as possible. In certain circumstances, for example if you
are a carer or have a disability, you may need to negotiate a reduced study load with
your teacher.
th
Date: 6 August 2011
Page 6 of 76
Attendance
You must attend class on time and as required. Please advise your teacher of any
planned long term absence (e.g. holidays).
Flexible / Distance participation requirements (where applicable)
You are expected to demonstrate participation within the learning activity for the unit/s
studied. You need to be in regular contact with your teacher to demonstrate your
progress and understanding of the content of the unit. Where directed you may be
required to submit activities or exercises to your teacher and respond to contact from
your teacher. No evidence of participation (or not achieving competency) may affect
Government benefits.
Confidentiality
Sometimes students are required to attend practical work placements as part of their
studies. During these placements, students may become familiar with information that is
confidential to that workplace. Students must not divulge any information that they may
become aware of during a placement.
Assessment procedures
Assessment will be conducted in an open, accountable and transparent manner with
particular emphasis on the aspects of fairness and equity for all. Assessment practices
will enable you to take full advantage of credit obtained from previous learning or study.
Assessment will incorporate alternative approaches to suit people who would otherwise
be disadvantaged by cultural background, language ability or personal disabilities.
You will be advised at the commencement of your program of the assessment
requirements. Instructions will be given prior to each assessment task. All assessment
work must be completed by due dates to be eligible for a qualification.
You are expected to complete all assessment items/assignments on or by the due dates
(unless an extension has been granted). In particular, tests are expected to be taken on
the dates specified and assignments are expected to be submitted by due date unless
otherwise negotiated with your teacher. Students who breach the above shall be issued
with a request to resit that assessment item within a defined duration of time.
Reasonable adjustment
A reasonable adjustment is an alteration of the assessment to accommodate the needs
of a student without compromising the integrity of the competence to be demonstrated.
For adjustments to be reasonable, they need to be appropriate for the particular student
in a particular situation.
Adjustments may be made to assessments to ensure they are equitable for all persons,
taking account of cultural and linguistic needs. Under the Disabilities Discrimination Act
1992, all training organisations have obligations to adjust their services to meet the
needs of students with a disability.
You may make a request for reasonable adjustment to your teacher or through the
th
Date: 6 August 2011
Page 7 of 76
Disability Officer, Student Services.
If a request for a reasonable adjustment is refused, or if you are not satisfied with the
adjustment made, you may lodge a grievance with the Education Business Manager.
Assessment variations/extensions
You should talk to your teacher if you are having difficulty meeting due dates for
assessment items. Teachers/tutors will take into account emergency situations and
unforeseen circumstances for students seeking an extension. The length of the
extension is at the discretion of the teacher. However, if the extension affects your close
of study date, or requires additional teaching hours, this must be authorised by the
Education Business Manager. A doctor‟s certificate must be produced to verify illness (or
other documentary evidence, where applicable).
Deferred assessment
You must apply to the Education Business Manager, in writing for a deferred
assessment, giving the reason for the request. The application is to be made at least
seven (7) days prior to the due date of the assessment, except in emergency
circumstances or in cases of serious illness or injury. A doctor‟s certificate must be
produced to verify illness/injury.
If the assessment date has passed, the application must be made within three (3)
working days of the concluding date on the medical certificate.
Retesting arrangements
If you are deemed “not satisfactory” after your first attempt at any assessment, you are
entitled to receive feedback from the teacher, amend your work and resubmit for reassessment or be retested on unsatisfactory elements after you‟ve had a chance to
revise the required skills and knowledge.
Supplementary assessment (for apprentices or trainees only)
Supplementary Assessment only applies after the apprentice/trainee has had
unsuccessful attempts of the assessment/s during a block/class. The apprentice/trainee
is then required to attend tutorial/s within a six (6) week timeframe from the end of the
block/class, to sit for the supplementary assessment/s (either the whole assessment
task or the part that wasn‟t satisfactory).
If the apprentice/trainee fails to attend the tutorials and/or the supplementary
assessment within the notified six (6) week period, and has not contacted us to request
an extension to this period, the apprentice/trainee is deemed to have failed the
supplementary assessment and will be issued with a final „not competent‟ result.
An extension to the training contract may be required if the assessment cannot be
completed by the nominal completion date. The apprentice/trainee training plan must
also be adjusted to reflect the extension, if approved by the Department of Education
and Training.
th
Date: 6 August 2011
Page 8 of 76
Re-evaluation of assessment item
If you are not satisfied with the result of an assessment item, you may submit a written
application for re-evaluation of the result to the Education Business Manager. This
request must be lodged, together with the scheduled charge, within 14 days of
notification of the result.
If the result is upgraded to successful, you will be refunded the scheduled charge. If the
student is dissatisfied with the re-evaluation outcome, they have a further right to appeal.
Appeals against the results awarded
If you disagree with the result awarded for your re-evaluation of assessment, you may
lodge a written application with the Director of Education and Training or make an
application using QF017 Notice of Academic Appeal. Please contact the Education
Business Manager for your area of study to help you through this process.
Complaints
If you have a concern regarding any aspects of your program, please discuss it with your
teacher so that assistance can be provided as quickly as possible. Addressing an issue
early generally means the problem will be solved sooner. If you are uncertain how to
approach an issue you can talk to your teachers, the administration staff within your
program area or a Counsellor from Student Support Services.
SkillsTech Australia has formal processes established to deal with complaints arising
from student and/or staff interactions and/or Institute procedures. Placing your
complaint in writing is a useful first step. Have your Say forms are available from our
Client Service Centres. You can also log onto our website:
http://www.skillstech.tafe.qld.gov.au/about_us/feedback.html
th
Date: 6 August 2011
Page 9 of 76
KS01-EJ102A Refrigerant tubing and fittings
techniques
Evidence shall show an understanding of cutting, bending and joining refrigeration piping and
tubing tools, equipment and techniques, applying safe working practices and relevant
Standards, Codes and Regulations to an extent indicated by the following aspects.
(a) Piping
 Refrigeration & water grade copper tube
 Maintaining cleanliness (always capped, do not blow out with mouth etc)
 Soft and hard drawn tube
 Tubing applications (soft, hard, pair coil, water grade etc)
 Tube qualities - diameter, wall thickness (gauge) and pressure ratings (R410A etc)
 Pipe insulation (types - tube, slit tube, sheet etc and joining methods - glue, tape etc)
 Other tube materials (Bundy, steel, aluminium, brass)
(b) Cutting
 Cutting tools (Imps, normal & large pipe cutters, tube cutting rings etc)
 Precautions while cutting (sharp burrs, sharp blades etc)
 Deburring tools (reamers, deburrers etc)
(c) Bending
 Bending tools (springs, levers, presses etc)
 Precautions while bending (work hardening, collapsing etc)
 Bending hard drawn tube - the process of annealing
(d) Joining
 Flare nuts (plain, short barrel, frost proof, reducing)
 Flaring tools (flare block, eccentric with clutch for high pressure tube)
 Precautions while flaring (de-burred, length past block face, cleanliness)
 Swaging tools (punch, flare block, expander etc)
 Precautions while swaging (length past block face, tube shortening effect, cleanliness
etc)
 Other tube fittings (BSP to flare elbows, tees, unions, plugs, flare washers, Lokrings etc)
 Thread sealants (tapes, pastes etc)
 Access valves (Schrader, piercing, cut-away of service valve/s)
 Precautions using access valves (refrigerant leakage, core removal, limitations on
piercing valves etc)
(e) Soldering and brazing equipment
 Gas types (oxy acetylene, air acetylene, propane, Mapp gas)
 Hazards associated with their use (cylinder transport, remove regulator, oil & oxy =
bang)
 Personal safety (MSDS - oxy, acetylene, propane, MAPP gas)
 Flash back arrestors
 Setting up equipment (fitting regulator, adjusting pressures, tip selection)
 Igniting and flame types (flint guns, oxidising, neutral, carburising)
 Care and maintenance of equipment (hoses, regulator, tips, cylinders, flash back
arrestors)
th
Date: 6 August 2011
Page 10 of 76
(f) Silver solder
 Types (yellow, brown, blue and their metal components)
 Personal safety (MSDS - silver brazing alloys)
 Flux and its use (dissimilar metals)
 Personal safety (MSDS - flux)
 Preparing surfaces (removing oxides, oils, applying flux)
(g). Soldering techniques
 Dry nitrogen
 Personal safety (MSDS - nitrogen)
 Applying dry nitrogen to a piping circuit
 Silver soldering copper to copper
 Silver soldering copper to dissimilar metals
 Annealing copper tube
th
Date: 6 August 2011
Page 11 of 76
Chapter 1 - Piping
Outcome
In this section you will learn to describe and identify various types of tubing and pipe insulation
and their applications in the refrigeration industry.
General references of this learning resource manual
The following references are recommended for use in this learning resource manual:
Principal reference
o
Boyle, G, Australian Refrigeration and Air Conditioning (ARAC) 4th Edition, Western
Australian TAFE Trust Publications. ARAC, 4th edition,

Chapter 9
Other useful references
o
AS/NZS 1571 Copper – Seamless Tubes for Air Conditioning and Refrigeration.
o
The Australian Refrigeration and Air Conditioning Code of Good Practice
o
AS 1432 Copper Tubes for Water Gas and Sanitation.
Videos

nil
Websites

www.boc-gases.com

www.cranecopper.com.au

www.masterplumbers.com/companies/kembla/

www.heatcraft.com.au

www.airefrig.com.au
Search Criteria

nil
Additional resources for this learning


Modern Refrigeration and Air Conditioning by Alfred F. Bracciano
Dossat, R.J. Principles of Refrigeration
th
Date: 6 August 2011
Page 12 of 76
Types of tube or pipe material
Common tube or pipe materials are:

Copper

Steel

Aluminium

Flexible (thermoplastic)
Applicable Standards
AS 1572: 1998 - Seamless tubes for engineering purposes
AS 1432: 2000 – Plumbing, gas fitting and drainage applications
AS 1571: 1995 – Seamless tubes for air conditioning and refrigeration
AS 4041: 2006 - Pressure piping
Copper pipe is supplied in both “Soft-Drawn” or annealed (heat treated to soften) in both coil
form and “Hard-Drawn” straight lengths. Copper pipe is manufactured in accordance with
standards and specified by the outside diameter and the nominal wall thickness.
Soft Drawn
Hard Drawn
Photos courtesy Logan TAFE
Copper tubing is supplied to various industry sectors e.g. Refrigeration and air conditioning,
plumbing and utilities industries. Copper pipe is processed in various ways in particular the
refrigeration industry pipe is highly processed.
Note! Water grade copper pipe can not be used in refrigeration
applications.
th
Date: 6 August 2011
Page 13 of 76
Important! Refrigeration copper pipe is supplied dried and sealed to prevent oxidisation and
should only be opened up when ready to install. All refrigeration pipe needs to be kept sealed to
prevent dirt and contaminants from entering the pipe until it is ready for use. The pipe is
supplied with special plastic caps and can be used to reseal any remaining pipe for future use.
Note! Copper pipe is unsuitable for use with ammonia refrigeration
systems – in the presence of moisture ammonia attacks copper and
brass
Advantages of Copper
1. Copper resists corrosion.
Excellent resistance to corrosion and scaling assures long trouble-free service with copper
which, in turn, means satisfied customers.
2. Copper is lightweight.
Copper tube does not require the heavy thickness of ferrous or threaded pipes of the same
internal diameter. This means copper costs less to transport, handles more easily and, when
installed, takes less space.
3. Copper is formable.
Because copper tube can be readily bent and formed, it is frequently possible to eliminate
elbows and joints. Smooth bends permit the tube to follow contours and corners of any angle.
4. Copper is easy to join.
Copper tube can be joined with capillary fittings. These fittings save material and make smooth,
neat, strong, and leak proof joints. No extra thickness or weight is necessary to compensate for
material removed by threading.
5. Copper is safe.
Copper tube will not burn or support combustion and decompose to toxic gases. Therefore, it
will not carry fire through floors, walls and ceilings.
th
Date: 6 August 2011
Page 14 of 76
6. Copper is dependable.
Copper tube is manufactured to well- defined composition standards and marked with
permanent identification so you know exactly what it is and who made it.
7. Copper is economical.
The combination of easy handling, forming, and joining permits savings in installation time,
material and overall costs. Long-term performance reliability and wide code acceptance make
copper the ideal cost-effective piping material.
Hard drawn copper pipe is available in 6 metre lengths and in various diameters including the
same diameters as soft drawn but extends further in diameters up to 100mm nominal.
Hard drawn copper pipe is used in commercial refrigeration and air conditioning systems and is
ideal for long pipe runs and being hard it requires few pipe supports. The maximum pipe
diameter for refrigeration applications is 100mm and lines above this size should be steel.
Common Pipe sizes
OD Inches
mm
Wall
OD Inches
mm
Wall (mm)
1/4 "
6.35
0.81
3/4"
19.05
1.14
5/16"
7.9375
0.81
7/8 "
22.225
1.63
3/8 "
9.525
0.81
1"
25.4
1.63
1/2"
12.7
0.81
1 1/8"
28.575
1.83
5/8 "
15.875
1.02
Note : for detailed information relating to the appropriate tube selection for
various pressure and temperature applications refer to suppliers product data.
Annealed copper pipe is heat treated and allowed to cool which allows the pipe to be more
flexible that is it is easier to be bent and flared (joining technique). Soft drawn copper pipe or
tube is commonly used in domestic and commercial refrigeration and air conditioning systems.
th
Date: 6 August 2011
Page 15 of 76
Pair Coil
„Pair coil‟ is pre-insulated soft drawn copper tube ideal for rapid, cost effective split airconditioning installations. Pair sizes are matched to standard split air conditioning pipe sizes.
Soft drawn or annealed tube is available in various standard sizes and roll lengths ranging from
4.76 mm up to a maximum of 22 mm nominal outside diameter (OD), and 15 or 30 metre roll
lengths.
Typical pair-coil sizes
Polyethylene insulation (courtesy Crane Copper)
Fire Retardant Pair Coil
The Building Code of Australia stipulates that the insulation on air-conditioning gas lines used in
class 2-9 buildings must comply with specification C.10 and C10a.
th
Date: 6 August 2011
Page 16 of 76
What are Class 2-9 buildings?

Class 2-9 buildings include multi occupier buildings and accommodation, business
premises including shops, professional chambers and factories, hospitals, aged care
facilities, schools and public assembly buildings.
What is specification C1.10 and C1.10a?

The fire hazard properties of any material or assembly in a class 2-9 building must
comply with Specification C1.10. I.e. must be made of;
(i)
“Sarking type” material: means a material such as a reflective foil or
other flexible membrane of a type used for a purpose such as water
proofing, vapour proofing or thermal reflectance or,
Picture courtesy of Kembla
(ii) “Other” material.
th
Date: 6 August 2011
Page 17 of 76
Table courtesy Kembla
Aluminium Pair Coil
Pre-insulated Aluminium Tube is carefully designed using high quality materials that is best
suited for split air-conditioning installation.
Flexibility & Strength

Higher wall thickness ( G18) provides better tensile strength
•
Lightweight & Durable Swaging & Expanding


30% expansion from original OD
Using the same set of swaging tools as copper
Burst Pressure

PSB TUV (Singapore) tested to meet ASTM B75 @ 1000PSI
Brazing & Repair






Armour Braze Rods allows up to 45-50 joints per rod ( 50cm rod)
No additional flux is required
Joints are stronger than main material
Fast & secured joints in less than 15s, 4 times faster than to braze copper
Uses the same method to braze copper
No argon gas, wire spool, gloves, shield or electricity required
Length & Packaging







Design to 50 metres length per coil
Longer length, less wastage
Offers more flexibility and does not kink easily
Able to withstand burst pressure of more than 1000psi without sign of leakage
Requires less strength to bend
•Using the same set of bending tools as copper
Manufactured up to 1.5mm wall thickness providing superior rigidity
th
Date: 6 August 2011
Page 18 of 76
Corrosion Resistance



48 hours salt water test before shipment
Corrosion rate is very much lesser than copper
Oxid isat io n r at e is also lo w er m akin g p ip es clean an d b r ig h t w h en exp o sed
Thermal Conductivity
 Lo w er t h an co p p er b y alm o st 50% w h ich m ean s lesser r at e o f co n d en sat io n
Copper Capillary Tube
Capillary tube is small inside diameter tubing used as a metering device (RMD) commonly used
for:

small hermetic refrigeration systems

household refrigerators and freezers

residential air conditioners

drinking water coolers

bottle cabinets

very low temperature systems.
Caution! Do not cut capillary tube with pliers
or side cutters.
Use capillary cutters, or another tool like side
cutters to score the outside of the capillary,
break the capillary by bending repeatedly at
the score line. Your class facilitator will
demonstrate how to do this.
Capillary Cutters
th
Date: 6 August 2011
www.airmender.com.tw
Page 19 of 76
Steel pipe
Steel pipe is available in various types including black steel, stainless steel and galvanized
steel. Steel pipe is cheaper and stronger compared to other pipe materials but does suffer
from rusting and corrosion.
Small bore steel tube is used in domestic
refrigeration as condenser coils and is
referred to as “Bundy” tube. Steel tubing is
also used on ammonia refrigeration plants
exclusively, as copper and brass, being non ferrous materials reacts with ammonia in the
presence of moisture.
“Bundy tube”
Applications
Stainless steel pipe is widely used in refrigeration systems where there is a need to refrigerate
process and or distribute food products directly such as ice cream, milk and beverages beer
and soft drink are good examples. The advantage of using stainless pipe is its resistance to
corrosion and can be easily joined with pipe of different material using common fittings and
brazing alloys.
Galvanized steel tube has been used on condensers on medium to large refrigeration and air
conditioning systems and are usually but not always involve evaporative (water and air
cooling). Galvanizing is an electrochemical process which protects the steel tube with a
bonded coating of zinc.
Aluminium pipe
Aluminium pipe has been used extensively in the automotive industry, for example as fuel lines,
hydraulic lines for brakes and steering systems and refrigerant tubes on car air conditioning
systems. It is a useful material as it is lightweight, cheap and capable of handling many
different types of fluids and gases. It also is prone to corrosion but less of a problem compared
to steel.
th
Date: 6 August 2011
Page 20 of 76
Aluminium is used extensively in domestic refrigerators and in domestic and light commercial air
conditioning systems.
Aluminium is difficult to join especially if it has already been in service and been contaminated
with refrigerant oil. Repair work which involves joining to copper is very difficult and epoxy
compounds have proven to be the most successful joining techniques.
Flexible thermoplastic pipe
Thermoplastic flexible pipe is used in a number of industry sectors in applications such as
hydraulics. The refrigeration industry is now employing more of this material in uses such as
pressure control lines oil return lines and compressor unloader control lines to name a few. The
material is compatible with all refrigerants (with steel fittings) including hydrocarbon refrigerants.
This material is resistant to corrosion and very tolerant to vibration. Tube joining is easily done
with crimping tools and fittings and in turn the fittings are connectable to standardised flare
fittings.
Picture courtesy FXMultitech PVT Ltd
Copper shroud – inserted between aluminium nut and brass flare flange in thermoplastic tubes.
Flexible thermoplastic pressure sensing lines.
Picture courtesy FXMultitech PVT Ltd
Picture courtesy Logan TAFE
th
Date: 6 August 2011
Page 21 of 76
Pipe insulation
Pipe insulation is necessary to prevent heat gain or loss depending upon what is being carried
inside the pipe.
If the pipe is a cold pipe the insulation prevents condensation, (water dripping), and causing
damage such as ceilings and creating a workplace hazard. If the pipe is a hot pipe heat lost
can be energy inefficient and insulation can lock in the heat to wherever it is needed for
example, hot water systems.
There have been many different types of pipe insulation over the years ranging from cork,
polystyrene, fibreglass and asbestos (which is now banned from use). One of the most common
modern pipe insulation materials is elastomeric cellular thermal insulation.
This product is usually black in colour and is a flexible foam type material. It is supplied in
standard 2 m tube lengths as well as sheet form and in a range of wall thicknesses from 6 mm –
50 mm. It can be cut or slit with a sharp knife or razor and can be joined using Neoprene
contact glue and tapes to ensure vapour seal. Manufacturers typically coat the inside of the
insulation with powder to help pipe to slide over copper pipe.
Tube insulation (copper & drains)
Sheet insulation (tanks etc). insulationireland.net
Caution! When slipping insulation over pipe ends leave pipe end caps
in place to prevent powder from entering pipe.
End of Piping - Now complete the review questions.
th
Date: 6 August 2011
Page 22 of 76
Review questions
1. State the difference between water and refrigerant grade copper pipe?
2. Can copper pipe be used with all types of refrigerants?
3. Give some examples of copper pipe sizes?
4. Explain what is meant by the terms soft and hard drawn?
5. Give some other types of pipe material other than copper?
6. Explain some reasons for using pipe insulation?
th
Date: 6 August 2011
Page 23 of 76
7. What are the advantages of hard drawn copper pipe?
8. What are the advantages of soft drawn copper pipe?
9. How can you join insulation to ensure a good vapour barrier?
End of Piping
th
Date: 6 August 2011
Page 24 of 76
Chapter 2 - Cutting
Outcome
In this section you will learn to accurately and neatly cut copper tube to acceptable industry
standards.
Principal reference


Chapter 9

nil
Videos

nil
Websites

www.cranecopper.com.au

www.reece.com.au/hvacr/products
Search Criteria

nil


th
Date: 6 August 2011
Page 25 of 76
Cutting - Tube
Tube cutting tools
Tube cutters have been developed to provide clean and easy cutting of soft pipe material
especially copper. Below are photos which illustrate the unique features of these tools.
Note! Never use hacksaws to cut copper tube for refrigeration
Roller
Flare cut-off groove
Cutting Wheel
Tightening Knob
Courtesy Logan TAFE
These tools do require light oiling occasionally and cutting wheels need to be changed when
worn. Spare wheels should always be carried and are easily available from refrigeration and
tool suppliers.
th
Date: 6 August 2011
Page 26 of 76
Imp cutters
Where pipe cutting access is difficult such as confined spaces small tube cutters have been
developed. These tools will cut tube with diameters up to around 19mm maximum.
industrialcleaningandofficesupply.com
From Nextag.com
Precautions when cutting
Whenever cutting tube always be sure that there is no pressure in the system. Always measure
twice before cutting and always be aware to minimise waste as pipe and particularly copper
pipe is expensive.
Deburring or reaming tools
After the pipe has been cut there is always a burr left just on the inside of the pipe which must
be removed. If the burr is not removed from the pipe the burr will cause problems later when
the pipe is flared. If the pipe is not being flared but simply is brazed into position the excess burr
can dislodge and contaminate the system.
Deburring tools have been developed for just this problem. The photo below illustrates two
types of tools available.
De-burring tool with replaceable blade
th
Date: 6 August 2011
Page 27 of 76
Inside tube reamer
Outside tube reamer
Photos by Paul Marshall Skills Tech Australia
End of cutting - Now complete the review questions.
th
Date: 6 August 2011
Page 28 of 76
Review questions
1. What type of tool is not to be used to cut refrigeration copper pipe?
2. Why is it important to remove the burr on the inside of pipe after tube cut?
3. Why is it important to make sure that there is no pressure remaining in pipe work before
cutting?
4. What is the name of the small tube cutter?
5. Another name for a deburring tool is
6. Why must the burr be removed after cutting?
End of Cutting
th
Date: 6 August 2011
Page 29 of 76
Chapter 3 - Bending
Outcome
In this section you will learn to bend copper tubing using spring and lever type bending tools
Principal reference

Australian TAFE Trust Publications. ARAC, 4th edition, Chapter 9 Specialised
tools

nil
Videos

nil
Websites

Nil
Search Criteria

nil


th
Date: 6 August 2011
Page 30 of 76
Types of tube bending tools
„Soft drawn‟ copper tube can be neatly bent using specially designed tools. Do not attempt to
bend hard drawn copper tube without annealing the area to be bent.
Bending springs
This is a very simple tool manufactured out of spring steel and is simply slipped over the copper
tube. Spring Benders:

use correctly to prevent tube flattening

up to 360deg (loop) can be bent

internal & external springs

good for bends to fit small spaces

minimum safe bending radius is five pipe diameters.

The bending spring is available in various sizes ranging to suit pipe sizes from 6mm to
19mm soft drawn tubing.

Refer Australian Refrigeration Air conditioning text pp.9.8 – 9.11
screwfix.com
rothenberger-usa.com
Pair Coil Benders
Crane Copper Tube Pair Coil Benders are manufactured from high grade extruded polyethylene
providing superior tube bending performance without the risk of kinks. High quality polyethylene
provides optimum bend angle while still allowing the coil bender to be extracted with ease.
th
Date: 6 August 2011
Page 31 of 76







Simple: Tube Pair Coil Benders are a
simple, easy to use accessory that allows
you to quickly and efficiently bend pair coil
tubing.
Prevents Tube Kinks: The flexible
polyethylene rods ensure an even radius
bend, preventing excessive stress on tube
walls, and thereby preventing kinks.
Clean: No mess, no fuss, low friction,
smooth polyethylene surface means no onsite clean up, and no contamination of the
tubing.
Effective: The flexibility and surface
properties of the polyethylene allows the
bender to easily slide into and out of the
pair coil tubing.
Reliable: Allows you to achieve tighter
bends while preventing tube kinks. The
best way to ensure you get the required
bends time and time again.
Saves Time: Saves you time with reliable
bends in just seconds without effort.
Saves Money: No more kinks – no more
wastage of kinked tubing – and no more
time wasted on re-bending or extra joints.
Mechanical or lever type benders
Mechanical bending tools are available in a number of different types. These tools can be
supplied as individual tools for a single pipe size ranging from 6mm to 19 mm also available are
three in one type benders – commonly 6, 9, and 12mm single tool. These tools have special
reference markings to assist in the bending process. And finally a bending tool kit with a single
lever tool with multiple heads ranging is size 6 – 22 mm.
Mechanical bending of soft copper will „work harden‟ the area. It may be necessary to anneal
the copper to perform other tasks like flaring.
th
Date: 6 August 2011
Page 32 of 76
Tube clamp
Marks for left & right side bending
Forming handle
Several tube sizes can be bent
with this bender
Forming wheel
Tube clamp
Several tube sizes can be bent
with this bender
www.nmri.go.jp
th
Date: 6 August 2011
www.albert-roller.de
Page 33 of 76
Annealing
Annealing is the process of softening metal particularly copper for further processing e.g.
swaging, bending, flaring.
The process involves heating the copper tube until the tube is just turning “cherry red” and
allowing the tube to cool. Make sure that a stream of Nitrogen gas is passed gently through the
pipe to ensure that no scale will form inside the pipe.
See soldering and brazing topic for further details.
Now complete the review questions.
th
Date: 6 August 2011
Page 34 of 76
Review questions
1. Name three methods used to bend refrigeration pipe?
i. ____________________________________
ii. ____________________________________
iii. ____________________________________
2. Why can‟t you bend “Hard Drawn” copper pipe?
3. Explain the term annealing?
4. Name one advantage of a bending spring?
End of Bending
th
Date: 6 August 2011
Page 35 of 76
Chapter 4 - Joining
Outcome
In this section you will learn to swage and flare copper tubing and identify common system
access valves.
Principal reference
o
Australian TAFE Trust Publications. ARAC, 4th edition

Chapter 9

nil
Videos

nil
Websites

Nil
Search Criteria

nil


th
Date: 6 August 2011
Page 36 of 76
Joining Pipe
There are a number of ways of joining tube to fittings and other tube materials. These
connection methods include:

Flare joints

Solder (brazing)

Compression fittings
Australian Refrigeration Air conditioning Chapter 9, text pp. 9.11 – 9.14
Flared connections
Flare nuts are available in a number of different sizes to suit the different pipe sizes ranging
from 6 – 19mm. Flare nuts are also supplied as plain (long barrel) short barrel and frost proof.
Plain barrel nuts are designed to provide the pipe with additional support but more room for
access is needed and short barrel nuts will allow tighter access but with reduced support. Frost
proof nuts are recognised by the holes drilled around the neck of the nut this prevents ice
forming and crushing down on the tube in low temperature ( sub zero temp.) applications.
Nuts available from Heatcraft.com
Short Barrel flare nut
Frost free flare nut
Flare nut and union.
The method of flaring involves mechanically forming a cone shape (female) at the end of the
pipe by flaring tools ( flare block and yoke) as illustrated below, which is later connected to a
compatible male fitting. This forms a gas tight fitting when the flare nut which sits in behind the
flare is screwed into position and tightened.
th
Date: 6 August 2011
Page 37 of 76
Flaring Tools
Connection of tubing to fittings is common practice and a flare-type connection is used.
Special tools are required for making flared joints, which consist of a:
1. Flaring block or anvil (various size holes in the block with 45 degrees chamfers)
2. Wing nuts
3. The spinner, which screws down onto the tubing, creating the flare.
R410a system flares differ having an angle of 46 o – 48o. The flare tool recommended for R410a
units is the clutch style.
Note: when flaring most size tubing, stick out the tubing approximately 1.0 mm to 2.0 mm above
the flare block to gain a good sized flare, (the tubing should not be too loose in the flare nut or if
it is too big, flare nut will not fit on).
A properly made flare provides a leak proof joint or vapour tight seal. Lubricating the mating
surfaces with refrigeration oil and on the fitting may prevent twisting of the tubing when
tightening the fitting.
Screw threads such as Gas thread, BSP, NPT need to have an approved refrigerant thread
sealant applied to the thread as the thread does not seal.
Flare yoke
Flare blocks
Swaging heads
Flare head
th
Date: 6 August 2011
Page 38 of 76
Another type of flaring tool that has been
developed for thicker wall pipe (R410A
refrigerant) but can still be used on standard
pipe is the eccentric clutch flaring tool. These
tools have some unique features such as
eccentric action to work the face of the flare to
provide a better flare finish and clutch to
prevent over tightening.
Male flare union
Flare nut spanners
Note! Always ream the pipe after cutting to ensure the burr is
removed and be careful not push the tube too far beyond the
block when flaring.
Swage joints and tools
Swaging or pipe expanding allows the joining of two pieces of “soft drawn” or annealed copper
tube to be joined without the need for special fittings. The pipe can be expanded using a
number of different techniques: Punch, Swage / flare block or Mechanical expander.
With the swaging punch the tube is supported and a tube expander punch is placed inside the
tube and is hit with a hammer and the tube is expanded. A very simple tool but requires a good
deal of skill to obtain a good quality swage.
th
Date: 6 August 2011
Page 39 of 76
Swage / flare block sets with mechanical expander heads that interchange with the flare cones
are also available and provide a good quality swage.
Finally, the mechanical swaging tool as illustrated below is the best method for swaging pipe
and is available with interchangeable heads to suit the various standard pipe diameters. These
range in sizes 9mm – 25mm. larger sizes are also available for industrial refrigeration
application with tools ranging up to 100 mm pipe diameter.
Mechanical swager
Expanding handle
Interchangeable
swaging head
th
Date: 6 August 2011
Page 40 of 76
Swaging head
Lever type handle
Swaging cone
Fixed handle
Joining Pipes – small inside larger
It is also practical to join pipes by placing a
smaller diameter pipe inside a larger pipe of
the next size and brazing. For example, ¼‟
inside 3/8‟, ½‟ inside 5/8, etc. The larger pipe
must be the next available size up from the
Constricting
wheel
smaller diameter pipe. Use a constriction tool
(picture on the left) to secure the pipes before
brazing. Ensure the small pipe is inserted a
minimum of one pipe diameter into the larger
pipe.
Compression fittings
This type of connection method has long been used in the plumbing, automotive, hydraulic and
pneumatic industries and is also used in the refrigeration industry particularly the ammonia
refrigeration sector. This method involves the use of a number of components typically rings
and cones depending on the type of application. Compression fittings are very effective in high
pressure applications.
Lokrings
A recent advanced compression fitting method uses special couplings and pliers with interchangeable fingers to suit same size or differing tube diameters. This method of tube
connection is proving very effective when joining differing pipe materials such as copper to
aluminium and where brazing is unsuitable e.g. dangerous environments or dangerous
refrigerants (hydrocarbons).
th
Date: 6 August 2011
Page 41 of 76
THE ADVANTAGES OF THE LOKRING PRINCIPLE

Approx. 40 % time saving

Absolutely clean, efficient and reliable

Installation work during business hours and public access

Installation work in situations where there is a fire hazard

Light hand assembly tool without energy exertion

Installation can also be carried out by non-skilled workers

No nitrogen as purge gas

No solder-related quality problems
The patented LOKRING tube connection works on the basis of simple physical laws. It consists
of two LOKRINGs and one tubular joint which takes the two tube ends. During assembly, the
tube ends are inserted into the joint to the inner limit.
All pictures courtesy Vulcan Lokring
th
Date: 6 August 2011
Page 42 of 76
Then an assembly tool is used to push the two LOKRINGs axially onto the joint. Due to the
conical inner contour of the LOKRINGs and the special outer and inner contour of the joint, the
diameter of the joint is reduced during assembly so that the tube and the joint form a metallic
hermetic connection through surface contact.
The lifetime air-tightness of the fitted connection is guaranteed by the state of permanent elastic
pre-tension, which is produced by the balance of the radial forces of the LOKRINGs acting in
the opposite direction to the tube to the LOKRINGs.
All pictures courtesy Vulcan Lokring
th
Date: 6 August 2011
Page 43 of 76
th
Date: 6 August 2011
Page 44 of 76
Thread sealants
The application of thread sealants is useful and sometimes necessary when screwing some
types of fittings into components which attach to pipe work.
Typical thread sealants include fluid products such as “Loctite” and thread tape sealants as
illustrated below. Care should be taken to ensure that tapes or sealant fluids do not enter the
pipe internally. This will result in system contaminants which can block controls and important
passages within the system.
Note! When using thread tape or fluid
sealants always check compatibility and
compliance with refrigerant, oil,
temperature and pressure
Leak Lock seals a broad range of chemicals
including all refrigerants such as R-12, R-22,
R-502, R-134A, etc., all CFC, HFC and HCFC
refrigerants, petroleum products, natural and
manufactured gases, steam, water, air, etc.
No other sealant offers the application range
Heatcraft.com.au
of Leak Lock.
Note! You should also be aware that these sealant products should not be considered as a
substitute for damaged threads or poor quality work. These products should only be used in
accordance with manufacturer‟s instructions.
Access valves
There are many different types of access valves into the system but the most common types
include:

Schraeder valves

Compressor service valves

Line valves with gauge ports

Piecing valves (bullet)
th
Date: 6 August 2011
Page 45 of 76
These valves provide access into the system for recording pressure which is necessary for
various processes such as pressure testing, evacuation, charging and fault finding.
Schraeder Valve with core removed
Compressor service valve
www.longviewweb.com
www.hvacfun.com
th
Date: 6 August 2011
www.service-1.org
Page 46 of 76
Bullet piercing valves are design to access small refrigeration systems – 6mm, (1/4"), 7.9mm
(5/16"), and 9.5mm (3/8)”.
2.6.1 Tube piercing or line tap valves and
other similar devices must be used only to
gain service access to the system in order to
remove refrigerant. They must be removed
before the completion of service. The system
design must not require these valves to be
left on the system after the completion of
service.
drillspot.com
Annealing
Annealing is the process of softening metal particularly copper for further processing e.g.
swaging, bending, flaring.
The process involves heating the copper tube until the tube is just turning “cherry red” and
allowing the tube to cool. Make sure that a stream of Nitrogen gas is passed gently through the
pipe to ensure that no scale will form inside the pipe. See soldering and brazing topic for further
details.
Other types of fittings
Other types of fittings used in the refrigeration industry include:
Male flare with BSP thread union. These are commonly used to provide access to the metal
compressor housing for manifold gauges, oil return lines and pressure controls.
www.fittingsexpress.com.au
th
Date: 6 August 2011
Page 47 of 76
Male flare elbows.
Often used as access fittings on compressors
www.fisheriessupply.com
Flare nuts
www.hellotrade.com
www.dallera-valerio.com
Flare caps
buildershardwarebelize.com
www.plumbingsupply.com
th
Date: 6 August 2011
Page 48 of 76
Copper Couplings
Used to join larger pip sizes and joining hard drawn tube.
www.1st-product.com
Copper pipe to flare fitting
Available in a range of sizes to fit brass flares onto copper tube.
BRASS UNION 1/2 MF X 3/4 FF (www.heatcraft.com.au)
th
Date: 6 August 2011
Page 49 of 76
Revision questions
1. Describe how a flare is obtained?
2. Flare fittings range in size from?
3. Describe the term swaging?
4. What process should be done to hard drawn copper pipe before attempting to swage?
5. Describe two types of swaging techniques?
th
Date: 6 August 2011
Page 50 of 76
6. Why can‟t a bullet piercing valve be left on a system?
7. What is a Schraeder valve used for?
8. What is the best application for a compression fitting in the HVAC industry?
End of Joining
th
Date: 6 August 2011
Page 51 of 76
Chapter 5 - Soldering and Brazing Equipment
Outcome
At the end of this section you should be able to:
 Identify the gas types typically used to produce a flame for soldering/brazing purposes
 List the hazards associated with their use (transport, oil + oxy etc)
 Examine applicable MSD sheets on each of the gases used and list any safety issues
 Describe the purpose of flash back arrestors and identify their location
 Select and setup the components necessary to perform a soldered/brazed joint using
oxy/acetylene equipment
 Select and setup the components necessary to perform a soldered/brazed joint using
MAPP gas equipment
 Correctly and safely ignite, adjust and extinguish a torch
 Identify the 3 flame types produced by an oxy/acetylene torch
 List the „good practice‟ procedures to follow with regard to care and maintenance of the
equipment:
Principal reference
 Boyle, G, Australian Refrigeration and Air Conditioning (ARAC) 4th Edition, Western
 Chapter 10 – Oxy-Acetylene Plants
 Chapter 10 – Brazing and Welding

nil
Videos

nil
Websites


www.boc.com.au
www.heatcraft.com.au
Search Criteria

nil


th
Date: 6 August 2011
Page 52 of 76
Soldering and Brazing equipment
This topic prepares the student to safely use the two main types of welding equipment used in
the HVAC industry. Brazing and soldering is a technique used to join copper, steel and brass
pipe.
Brazing
Brazing is adhesion of one plate to another without melting at temperatures above 450°C but
below the melting point of the base metal. The filler material to form the union is non-ferrous.
Soldering
Soldering is also adhesion at a lower temperature. Filler metal or solder alloy with a melting
temperature of less than 450°C is used. The filler metal wets the parent metal, spreads, makes
contact with the joint opening and is drawn into the joint by capillary action.
Brazing and soldering is carried out using fuel gases – acetylene and oxygen, and MAPP gas.
Gas types used for soldering and brazing
Acetylene Overview
Acetylene is manufactured commercially by reaction between calcium carbide and water, and
as a by product of ethylene production.
Acetylene is most commonly used in combination with oxygen for cutting or welding materials
such as mild steel, where the standard industrial grade is sufficient. Acetylene with low
phosphine levels is required for lead brazing or welding.
Characteristics
This gas is flammable. It is also colourless with ether-like odour when it is very pure, otherwise
garlic-like. Supplied dissolved in acetone or DMF (N, N-dimethylmethanamide). Can
decompose instantaneously at pressures higher than 1 bar. Acetylene can be delivered as a
non-dissolved gas for specific R&D applications. Some of the health risks involved is that it can
be an asphyxiant in high doses and an anaesthetic.
th
Date: 6 August 2011
Page 53 of 76
Dissolved Acetylene (CH2)
Features






the hottest and most efficient of all the fuel gases, providing high levels of productivity
very efficient use of oxygen
lighter than air and will not accumulate at low levels
low ignition energy
low moisture content flame
non-toxic (may cause dizziness in high concentrations)
Benefits








oxygen and acetylene together produce a flame temperature of approximately 3150°C
the oxy-acetylene flame gives very good localised heating with a minimum of wasted
heat
in cutting, oxy-acetylene gives the fastest preheating and piercing times of any fuel gas
combination
in oxy-acetylene cutting processes, improved cut quality, higher cutting speed, faster cut
initiation time and reduced oxygen use are achieved
when used with either oxygen or air, acetylene can produce a thin layer of black carbon
particles. This can prevent components sticking in their moulds
unused gas will not collect in low-lying areas, ducts and drains causing a potential
hazard
acetylene is stored in specially-designed cylinders to prevent decomposition
the flame has a low moisture content making it a good choice for many critical heating
applications
Some applications









cutting
flame heating
flame gouging
gas welding. The only fuel gas which can be used to weld steel
flame hardening. An oxy-acetylene flame can be used where the hardened surface of
carbon steel components is either in situ as a remedial process or on components too
large to fit in a furnace
flame cleaning. A wide oxy-acetylene flame is held very close to a steel surface to be
cleaned
flame straightening where the precise and efficient flame properties are used to remove
distortion in plate material
brazing
profile-cutting
th
Date: 6 August 2011
Page 54 of 76
Please note: in any confined spaces, extraction devices should be used to remove any
potentially dangerous by-products.
Material Compatibility




Acetylene can ignite and burn instantly from a spark or piece of hot metal.
It can form explosive acetylide compounds with some metals, most notably copper,
silver and mercury.
Please note: copper alloys containing less than 65% copper and silver solder containing
less than 43% silver are considered safe.
Hoses used with acetylene are coloured red and are designed to resist acetone. For this
reason other fuel gas hoses must not be used.
Hazards




care must be taken when using acetylene as it is an asphyxiant
acetylene is highly reactive. It is dissolved in acetone and contained within a porous
mass inside the cylinder
acetylene can react over time with some metals to form explosive acetylides
acetylene is slightly lighter than air and will collect at ceiling level
The main parts of an oxygen/acetylene (oxy
set) plant are:

Oxygen cylinder (black)

Acetylene cylinder (crimson / maroon)

Cylinder valves and key

Regulators (acetylene has left-hand
threads for the hoses)

Gauges (separate indicators for
contents and pressure)

Hoses (acetylene hoses are RED)

Welding torch (or blowpipe)

Hand piece with left-hand threads for
acetylene hoses

Tips- brazing, welding and cutting

Control valves

Mixer
th
Date: 6 August 2011
Page 55 of 76
MAPP Gas
MAPP gas is liquefied petroleum gas mixed with methylacetylene-propadiene. MAPP is the
tradename for a product of the Dow Chemical Company. In Australia it is known as „RazorGas‟
and is a trademark of ELGAS. MAPP is colourless in both liquid and gas form. The gas has a
pronounced garlic or fishy odour at concentrations above 100 ppm and is toxic if inhaled at high
concentrations.
th
Date: 6 August 2011
Page 56 of 76
These high temperature self igniting torches have been designed as an easy to use, lightweight
and convenient welding/soldering torch. MAPP gas torches:

Eliminate the need to lug those heavy oxy/acetylene cylinders around.

Both have in-built heavy duty piezo ignitors and connect directly onto a Mapp Gas
cylinder.
Hazards
There are many hazards associated with the use of oxygen, acetylene and MAPP gas cylinders,
the following 10 tips should be adhered to prevent injury or damage.
Ten Steps to Cylinder Safety:
1. Read labels and Material Safety Data Sheet (MSDS) before use.
2. Store upright and use in well ventilated, secure areas away from pedestrian or vehicle
thoroughfare.
3. Guard cylinders against being knocked violently or allowed to fall.
4. Wear safety shoes, glasses and gloves when handling and connecting cylinders.
5. Always move cylinders securely with an appropriate trolley. Take care not to turn the
valve on when moving a cylinder.
6. Keep in a cool, well ventilated area, away from heat sources, sources of ignition and
combustible materials, especially flammable gases.
7. Keep full and empty cylinders separate.
8. Keep ammonia based leak detection solutions, oil and grease away from cylinders and
valves.
9. Never use force when opening or closing valves.
10. Don‟t repaint or disguise markings and damage. If damaged, return to BOC immediately.
Transport
Cylinders should be transported in an open vehicle (ute) and secured tightly and upright. When
cylinders are continually transported in enclosed vehicles (such as ambulances, service vans
with welding equipment, etc.) the following is recommended:

A permanent system should be in place to secure the cylinders (gas cylinders
and cryogenic liquid receptacles).

The vehicle should be equipped with adequately sized ventilation openings.

The cylinders should be carried in a separate, gas tight compartment, ventilated
to the outside.
th
Date: 6 August 2011
Page 57 of 76
Acetylene cylinders are to be used standing vertically on their base: Acetylene cylinders
are transported standing vertically and are designed to be used in an upright position. For this
reason, always store and leave these cylinders standing vertically. Should acetylene cylinders
have been stored or transported horizontally, place the cylinders in a vertical position and allow
4 hours before use.
Downloaded from https://boc.com.au/boc_sp/au/downloads/gas_brochures/BOC_Guidelines_for_Gas_Cylinder_Safety.pdf
Personal Safety
Use correct Personal Protective Equipment (PPE)
When welding or cutting use goggles with double lenses to protect your eyes against glare and
mechanical impact from flying fragments. The inner lens should be tinted and the outer lens
clear. The clear outer lenses should be changed regularly when spatter builds up. It is also
advisable to wear eye protection (spectacles or goggles) when handling high pressure gases to
protect the eyes against flying dust particles in the gas stream.
Do not wear clothes made of highly combustible materials. Leather gloves or gauntlets should
be used when necessary. In awkward work locations additional protective clothing may be
required.
th
Date: 6 August 2011
Page 58 of 76
Recognise the hazards of backflow and take suitable precautions. Safety hazards can be
created if contaminants are allowed to pass back into the cylinder. Precautions must be taken to
ensure that when the cylinder is in use no back feeding of gas or liquid can occur. As soon as
the gas in the cylinder has been used, close the cylinder valve to avoid moisture and other
contaminants entering the cylinder.
Remember the following:

Wear appropriate protective clothing.

Keep plant in good order and clean.

Do not store or operate the acetylene cylinder lying down (liquid acetone may pass
through)

Do not use grease or oil on fittings likely to come into contact with oxygen as this could
cause an explosion.

Keep the cylinders cool.

Never exceed 105 kPa for acetylene.

Do not use a plant that may have leaking hoses.

NEVER USE DISPOSABLE BUTANE LIGHTERS TO LIGHT THE BLOWPIPE, THEY
CAN EXPLODE VIOLENTLY. USE ONLY PROPER STRIKERS.
Flashback arrestors
Backfires and flashbacks: Backfires occur when the torch flame burns back into the torch tip
and is extinguished with a loud pop. They occur either because the torch tip touched the work or
because of insufficient gas pressure. They are generally harmless. However, flashbacks are
more serious when the flame front does not extinguish, but burns back sometimes beyond the
mixing chamber, through the hoses, and even into regulator and supply
A flashback is a flame, travelling at supersonic speed, in the opposite direction to normal gas
flow in oxy-fuel gas equipment. The use of flashback arrestors is required to limit the potential
damage that may result if a flashback occurs. If not stopped, a flashback can melt the
equipment which, in the worst case, could explode and travel back to the cylinder.
th
Date: 6 August 2011
Page 59 of 76
Flashback Arrestors: Prevents a flame from travelling past the flashback arrestor in
the event of a flashback.
Courtesy www.thermadyne.com
Flashback arrestors have a sensitive non-return valve that stops the gas flow and a fine sintered
filter that quenches the flame.
On the regulator end of the flashback arrestor, a thermal cut off valve is built in. This valve will
stop the flow of gas before ignition upstream occurs. To ensure total safety and protection from
the causes and effects of flashbacks, flashback arrestors should be fitted to each gas line, as
the risk of a reverse flow of gas exists with both oxygen and fuel gas. According to AS 4839
flashback arrestors should be tested every year.
Setting Up an oxy/acetylene set
1. Select the oxy bottle.
2. Select the acetylene bottle.
3. Fit the oxy / acetylene regulator gauges and lines to the bottles.
4. Select and fit appropriate tip to welding torch.
5. Attach the welding torch to the gauge lines.
th
Date: 6 August 2011
Page 60 of 76
6. See that the regulators are closed (unscrewed).
7. Open the bottles approximately HALF a turn slowly.
8. Adjust the gas pressures to the required values (about 50 kPa for both oxygen and acetylene
is typical) and purge lines.
9. Using the flint gun, light the welding torch and adjust the flame to a Neutral, Oxidising, and
Carburising flame.
10. When finished the weld, turn off the torch by closing the acetylene then the oxygen.
Note: When igniting the oxy-acetylene plant always turn the acetylene on first then add oxygen
and when turning off the blowpipe, always turn the acetylene off first then the oxygen as this will
blow out any flame that may exist. For most refrigeration work the gas pressures used for
oxygen is approx 50 kPa and acetylene is approx 50 kPa.
Note: The operating pressure of acetylene must not exceed 105 kPa; otherwise liquid acetone
may be discharged from the hose
cedar--rapids.com
Oxygen regulator (CIG Thermadyne)
th
Date: 6 August 2011
Igniter
Page 61 of 76
Igniting - Carrying Out the Skill Practice Procedures
Flame adjustment: Turn on and light the ACETYLENE first and adjust the flame until there is a
minimum of soot. Open the oxygen valve slowly and adjust the flame to the required setting.
There are three basic types of flame:
• Carburising flame -this flame has an excess of acetylene.
• Neutral flame - this is a general purpose type of flame with equal amounts of oxygen
and acetylene.
• Oxidising flame - this flame has an excess of oxygen.
In most refrigeration brazing a neutral flame is used, but oxidizing and carburising flames are
used in certain applications, e.g. braze welding (slightly oxidizing) and hard facing (carburising).
Stage 1 blue reducing zone
1 vol oxygen
Maximum
Temperature
1 vol acetylene
Stage 2 pink envelope
http://www.meg.co.uk/courses/4.php
Note: MAPP gas does not have any adjustment in the type of flame.
Care and Maintenance of equipment
NEVER let oil or grease contact your cylinder or its valve and fittings; use sealants or lubricants
when connecting gas fittings or equipment.
NEVER use cylinders as support structures.
NEVER roll them along the ground.
NEVER lubricate cylinder valves and fittings.
NEVER apply sealants (liquid or tape form) or lubricants to any cylinder valves or connecting
fittings. High pressure oxygen will react violently with oils and grease and cause a violent
explosion or localised ignition leading to injury of the user and damage to equipment.
th
Date: 6 August 2011
Page 62 of 76
Oxygen equipment is at most risk from oil and grease so keep greasy hands, rags and gloves
away from any part of the cylinder and fittings.
Wipe hands clean and try to minimise hand contact with surfaces which might be subject to
oxygen under pressure.
Keeping cylinder valves clean
Cylinders are supplied with their cylinder valve outlets capped or plugged and in some cases
PVC shrink wrapped.
The purpose of this is two fold:
1. To indicate the cylinder is full and
2. To keep the outlet clean and contamination free. Top outlet valves, are particularly prone to
dirt getting in the outlet.
Store the regulators in a protective box or case to prevent damage.
Hose care:

Regularly check the hoses for wear and tear, physical damage – splits or cracks.

Store hose out of direct sunlight when not in use to prevent sun damage and
unnecessary wear

Never leave a hose under pressure when not in use (connected to a trigger gun or stop
valve) and turn off the tap after each use to preserve the hose

Avoid running heavy objects over a hose, such as full wheel barrows or cars, as this
could cause unnecessary damage

Where possible pick up a hose and carry it rather than dragging it across concrete or
around brickwork as this can create unnecessary wear and tear to the hose and its
fittings

Avoid contact with harsh chemicals and caustic substances as this could also damage
the hose

Do not drop the hose end with a welding tip on to concrete or other hard surfaces, as the
impact could damage the tip and fittings
th
Date: 6 August 2011
Page 63 of 76
Review questions
1. What is the colour of the Oxy bottle? ________________________
2. What is the colour of the Acetylene bottle? ________________________
3. Is the use of oil or grease permitted on any of the oxy / acetylene fitting? Explain your
answer.
4. Explain what a carburising flame is and how it is produced.
5. Explain what a neutral flame is and how it is produced.
6. Explain what an oxidising flame is and how it is produced.
7. What is flash back and how is it prevented?
th
Date: 6 August 2011
Page 64 of 76
8. The operating pressure of acetylene should never exceed: ___________kPa
9. Describe the best method to transport cylinders (bottles).
End of Soldering and Brazing Equipment
th
Date: 6 August 2011
Page 65 of 76
Chapter 6 - Silver Solder
Outcome
In this section you will learn to identify, list and describe the various silver solder alloys and
associated flux and state their appropriate applications.
Principal reference

Boyle, G, Australian Refrigeration and Air Conditioning (ARAC) 4th Edition,
Western Australian TAFE Trust Publications. ARAC, 4th edition, Chapter 10

nil
Videos

nil
Websites

www.boc.com.au Technical Resources and MSDS
Search Criteria

nil


th
Date: 6 August 2011
Page 66 of 76
Types of Silver Solder
Common silver brazing rods used in the refrigeration / air conditioning industry are:
Yellow Tip Is used for flux free brazing of copper:
Yellow tip is free flowing than brown tip and is only suitable for copper to copper joints.
As it has a free flowing capillary action, tight fit-ups are necessary. Because of its lower
silver content, a yellow tip joint is less costly but not as strong as a brown tip joint,
therefore its use in vibration situations should be avoided.
Brown Tip Is used for high shear strength flux free brazing of copper.
Brown tip is used for joining copper tubing and other copper to copper applications
without flux where a strong joint is required, e.g. vibration situations. Because of its
medium capillary flow, fit-ups should be from 0.05mm – 0.15mm.
Blue Tip Is a low temperature, general purpose alloy.
Blue tip is used where a very strong joint is required between dissimilar metals, e.g.
joining copper, steel or brass pipe and fittings. The correct flux must be used on all
applications.
Silver Solder Brazing Alloys
% SILVER
ALLOY NAME
MELTING RANGE °C
COLOUR CODE
2
AMFOS
644 – 740
Yellow
15
SIL-FOS
644 – 700
Brown
45
EASY-FLO
607 – 620
Blue
Personal Safety – silver Solder MSDS
Refer to the MSDS 6021 Silver Coat 45, GB002 Flux coated Brazing Alloys, and GB003 Bare
Silver based (cadmium free) Brazing Alloys www.boc.com.au follow the MSDS link.
th
Date: 6 August 2011
Page 67 of 76
When using these rods as part of the brazing process additional potential hazards are likely:

Hot metal spatter and heat from the brazing flame, which can cause burns to the hands
and body, and may cause fire if in contact with combustible materials.

Radiation from the brazing flame, which can produce skin burns and possible eye
damage to unprotected eyes.
WEAR SUITABLE PROTECTIVE EQUIPMENT.

Fumes produced from the brazing consumable, material being brazed, and the brazing
flame:

Particulate fume such as complex metal oxides and silicates from the weld materials.

Gaseous fume such as carbon monoxide and dioxide from the oxidation of carbon in the
components and from the flame combustion products.

SHORT TERM INHALATION OF THESE FUMES AND GASES MAY LEAD TO
IRRITATION OF THE NOSE, THROAT AND EYES.

LONG TERM OVEREXPOSURE OR INHALATION OF HIGH LEVELS OF FUMES MAY
RESULT IN HARMFUL EFFECTS TO THE RESPIRATORY SYSTEM, CENTRAL
NERVOUS SYSTEM AND LUNGS.

LOCAL EXTRACTION AND /OR VENTILATION SHOULD BE USED TO ENSURE
THAT ALL HAZARDOUS INGREDIENTS IN THE FUME ARE KEPT BELOW THEIR
INDIVIDUAL OCCUPATIONAL EXPOSURE STANDARDS IN THE WELDER‟S AND
OTHER WORKERS‟ BREATHING ZONES.

NOTE: If brazing is performed on plated or coated materials such as galvanised steel,
excessive fumes may be produced which contains additional hazardous components,
and may result in metal fume fever and other health effects.
Flux and its uses
Fluxes
These are chemical compounds used to prevent oxidation and other unwanted chemical
reactions. They help to make the welding process easier and ensure the making of a good
sound weld. Some fluxes can be corrosive and thus particular care must be taken to remove all
traces of them after welding by washing and scrubbing in hot soapy water. Ranges of brazing
fluxes are available to suit the metals being joined.
th
Date: 6 August 2011
Page 68 of 76
EASY-FLO Flux Paste
A general purpose flux with good fluxing activity and long life at temperature. Working Range:
550 to 800°C
All brazing or soldering involving fluxes should be performed in a well ventilated
area, as fumes produced can be harmful to health.
Personal Safety - Flux
Refer to the MSDS ACPEE Flux Paste. www.boc.com.au and follow the MSDS links.
HSNO Classification:
6.1D - Substance that is acutely toxic if swallowed.
6.1D - Substance that is acutely toxic by inhalation.
6.3A - Substance that is irritating to the skin.
6.4A - Substance that is irritating to the eye.
Hazard Statement Codes:
H302 Harmful if swallowed.
H332 Harmful if inhaled.
H315 Causes skin irritation.
H320 Causes eye irritation.
P104 Read Safety Data Sheet before use.
P261 Avoid breathing dust, fume, mist or vapours.
P264 Wash hands thoroughly after handling.
P270 Do not eat, drink or smoke when using this product.
P271 Use only outdoors or in a well-ventilated area.
P280 Wear protective gloves, eye protection and face protection.
th
Date: 6 August 2011
Page 69 of 76
Preparing Surfaces
Be sure to remove all oxides and surface oils with abrasive cloth, pads, or brushes before
joining the metals. Such contaminants interfere with the proper flow of filler metal and may
lessen the joint strength or cause failure.
Chemicals cleaners may be used if they are thoroughly rinsed off, but be sure you don't touch
the clean surface with bare hands or oily gloves.
Apply a thin, even coating of flux with a brush to both surfaces soon after cleaning. Do not apply
the flux with your fingers because the chemicals in the flux can be harmful if it comes in contact
with your eyes, mouth, or open cuts.
Support the surfaces securely and ensure an adequate capillary space between them for the
flow of the molten brazing filler. Excessive joint clearance can lead to cracking under stress or
vibration. A joint clearance of 0.001 to 0.005 in. will develop the maximum joint strength and
soundness.
Use only the amount of heat necessary to melt and flow the filler metal. Overheating the joint or
directing the flame into the capillary space can burn the flux, destroying its effectiveness and
preventing the filler metal from entering the joint properly. Apply the heat around the joint area
to draw the filler metal into the capillary space.
Allow the completed joint to cool naturally. Shock cooling with water may stress or crack it.
When it is cool, clean off any remaining flux residue with a wet rag and test all completed
assemblies for joint integrity.
th
Date: 6 August 2011
Page 70 of 76
Review questions
1. What is the % of silver contained in a yellow tip brazing rod? ________________%
2. What is the % of silver contained in a brown tip brazing rod? ________________%
3. What is the % of silver contained in a blue tip brazing rod? ________________%
4. What is the main reason for using flux when we silver braze fittings in a refrigeration system?
5. Why is it important to remove any flux residue after the completion of the soldering process?
6. What is the purpose of the MSD sheet?
End of Silver Solder
th
Date: 6 August 2011
Page 71 of 76
Chapter 7 – Soldering techniques
Outcome
In this section, and combined with the practical tasks, you will learn to silver solder copper to
copper, copper to dissimilar metals, anneal copper tube and use dry nitrogen when brazing
including:
1. Identifying dry nitrogen cylinder and regulator and state the reason for its use.
2. Examine applicable MSD Sheets
3. Correctly and safely apply dry nitrogen to a pipe circuit
4. Produce a leak proof soldered copper to copper and copper to dissimilar metal joint neatly
and safely, and
5. Safely anneal hard drawn copper tube
Principal reference
 Boyle, G, Australian Refrigeration and Air Conditioning (ARAC) 4th Edition,
Western Australian TAFE Trust Publications. ARAC, 4th edition, Chapter 10

nil
Videos

nil
Websites



www.boc.com.au Technical Resources and MSDS
www.kembla.com.au
Search Criteria

nil


th
Date: 6 August 2011
Page 72 of 76
Practical assessment tasks
This section is to be read in conjunction with the practical assessment tasks that will be carried
out in the workshop. Your class facilitator will provide the correct materials and instructions.
Dry Nitrogen
Safety information Nitrogen

Nitrogen is a non toxic and non-reactive except at high temperatures.

If insufficient oxygen is present, high nitrogen concentrations cause asphyxiation and
death.

There are no physiological warning signs to nitrogen enrichment.

Nitrogen does not support combustion.

Liquid nitrogen has the capacity to inflict dangerous cold burns.

Used in the refrigeration industry as a process of purging to displace or dilute unwanted
gas or vapour, to reduce oxygen concentration or remove air, flammable or toxic vapour.

Used in the refrigeration industry to pressure test systems and components.
Purging nitrogen through the pipework during brazing displaces the oxygen and prevents
oxidation – the chemical process of forming black copper oxide (scale) when heating copper in
the presence of air.
2 Cu(s ) + O2(g ) --> 2 CuO(s )
Personal safety
Nitrogen is supplied in cylinders that may have an internal pressure as high as twenty thousand
kilopascals (20 000 kPa). A regulator must be used to regulate the cylinder pressure through
refrigeration gauges into a system.
Remember! Always wear safety glasses to prevent eye injuries in the event of a
component failure.
th
Date: 6 August 2011
Page 73 of 76
Photos courtesy SkillsTech Australia – Bracken Ridge (Paul Marshall)
Applying dry nitrogen to a piping circuit
Attach a regulator to the nitrogen bottle, and a set of refrigeration gauges. Attach the common
line (yellow) to the regulated (outlet), and the high side line (red) to the system.
Open the bottle and ensure the pressure is sufficient for the task. Open the high side gauge and
then wind in the regulator handle until the desired pressure is achieved. (Regulator valves work
opposite to water taps – wind in for more pressure, and wind all the way out for zero pressure).
When using nitrogen for brazing, a low pressure is required – approximately 5 - 10 PSI or 50 70 kPa. Ensure there is an open end in the system to stop pressurization of the system, and
prevent holes being blown in the solder.
th
Date: 6 August 2011
Page 74 of 76
Brazing In Six Easy Steps
1. Cut the tube ends square, deburr, and if soiled or
excessive oxide has built up, clean the surface with a light
grade emery tape or wire brush.
2. Push the tube tightly into the fitting or the expanded end
or the other tube and apply heat. Brazing torches fuelled
with air-acetylene, propane-oxygen or oxyacetylene torches
are all suitable.
3. Apply heat uniformly to both tube and fitting, by moving
the torch around to ensure even heating before adding the
silver solder.
4. As the heated area gradually changes colour to a bright
red, apply silver solder by lightly brushing the tip of the stick
into the shoulder of the fitting. If sufficient heat is being
applied, the solder should melt on contact and flow into the
capillary space between the tube and the fitting. Keep a
cherry red colour, not a bright red. As the heat is applied
evenly around the joint, the molten brazing alloy will be
automatically drawn in by "capillary action". Care should be
taken not to over heat the tube.
5. To complete the joint, an even build-up of solder should
be just visible around the shoulder of the fitting. Remove
the heat (taking care not to disturb the joint) until the molten
brazing alloy solidifies to a tan black colour (approx. 10-15
seconds) After brazing is completed, the joints are normally
left to cool in the air. However, if necessary the joints may
be quenched in water or cooled with a wet rag.
6. To braze an upwards vertical joint follow the same
procedures, although more heat should be concentrated on
the fitting than the tube. This will draw the molten brazing
alloy upwards into the capillary gap.
Courtesy Kembla retrieved on 28 April 2011 from: http://www.kembla.com.au/assets/Uploads/general-PDFs/Brazing-Manual.pdf
th
Date: 6 August 2011
Page 75 of 76
Silver soldering copper to dissimilar metals
Procedure
1. Clean the ends of the copper tube with emery paper.
2. Apply Flux to all surfaces,
3. Use blue tip silver solder (45 %)
4. Place the copper tube inside the brass fitting,
5. Light the welding torch and adjust the flame,
6. Apply heat to the joint and silver solder the two pieces of tube together.
7. Caution: do not overheat the joint and use plenty of flux.
Brazing Copper Tube to Brass and other Copper Alloys
1. These combinations of materials require the
use of a non-aggressive, water soluble flux.
Using a brush or a clean rag apply a small
amount of flux to the end of the tube and to the
inside surface of the fitting. Avoid overloading
and spilling flux inside the tube itself as the
residue needs to be removed on completion of
the joint.
2. The procedures for these joints are
essentially the same as for Copper to Copper
jointing, only that more heat should initially be
concentrated on the brass or copper-alloy
fitting to bring it to temperature. Take care not
to overheat the fitting. Dull red colour is
sufficient
Courtesy Kembla retrieved on 28 April 2011 from: http://www.kembla.com.au/assets/Uploads/general-PDFs/Brazing-Manual.pdf
Turning off the oxy/acetylene set
It is very important that when finished using the oxy/acetylene set, it is safely stored in the work
shop or service vehicle. The following procedure is recommended before storing the oxy set:
1. turn the oxygen off at the bottle,
2. turn the acetylene off at the bottle,
3. open the oxy and acetylene valves at the torch and bleed all gas from the
lines,
4. set the regulated oxy gauge to zero (turn anti-clockwise all the way out),
5. set the regulated acetylene gauge to zero (turn anti-clockwise all the way
out),
6. Ensure all gauges are reading zero pressure. Remove regulators and hoses
from the bottles. Neatly coil the hoses and store where they will not be
damaged.
Store the cylinders upright and secure correctly. Always refer tho the manufacturer‟s
recommendations and MSDS for more detailed information.
End of Workbook
th
Date: 6 August 2011
Page 76 of 76

Table Of Contents - HVAC Education Australia

Transcription

Similar documents

9x16 Projector Screen Frame Kit

FR Three-layer Polyurethane Tubing

Product information sheet

Snow Tubing Night A Benefit Fundraiser for Home Base Ride the

Application Type 1202 all polyethylene instrument tubing bundles

- Unistrut UK

Flat B, 5 Marlborough Road, South Croydon, CR2 6JD

MC Fittings

zazu`s

CWB_OnePage_ACTRA copy