This document provides instructions for performing oxy-acetylene welding. It outlines the necessary equipment including an oxy-acetylene welding rig, goggles, pliers, and wire brush. The materials are listed as mild steel plates. Safety procedures are described such as wearing protective equipment and knowing the location of emergency equipment. The document then explains the oxy-acetylene welding process and provides step-by-step instructions for welding two steel plates together, including igniting the torch and controlling the molten weld pool. Assessment criteria for evaluating the quality of the welds are also presented.

1. JM101 MECHATRONIC ENGINEERING PRACTICE 1 GAS WELDING
NO OF PROJECT : K/01/PJB
TITLE : OXY-ACETYLENE WELDING – Welding without filler rod
1.0 COURSE LEARNING OUTCOMES
Upon completion of this workshop, students should be able to :
1.1 practice correctly safety procedures in the workshop ; and
1.2 carry out correctly basic gas welding works involving various processes of welding and
types of joining metals according to SOP.
2.0 OBJECTIVES
2.1 Producing fine and even beads with uniform penetration (Refer to diagram K/01/PJB)
3.0 APPARATUS/EQUIPMENT
3.1 Oxy-acetylene gas welding equipment
3.2 Goggle or face shield
3.3 Spark lighter
3.4 Plier
3.5 Wire brush
Figure 1 : Oxy-acetylene gas welding equipment
4.0 MATERIAL
4.1 Mild steel plat (100mm x 50mm x 2mm)
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2. JM101 MECHATRONIC ENGINEERING PRACTICE 1 GAS WELDING
List out the apparatus/equipment and material
Draw the apparatus/equipment and material
used in the workshop
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3. JM101 MECHATRONIC ENGINEERING PRACTICE 1 GAS WELDING
5.0 SAFETY AND HEALTH
It is the individual’s responsibility to practice the following general safety guidelines at all times and
keep your workspace reasonably tidy.
5.1 Always know the hazards associated with the equipment/materials that are being utilized
in the workshop.
5.2 Always wear appropriate protective clothing and equipment.
5.3 Confine long hair and loose clothing. Do not wear high-heeled shoes, open-toed shoes,
sandals or shoes made of woven material.
5.4 Be familiar with the location of emergency equipment such as fire alarm and fire
extinguisher. Know the appropriate emergency response procedures.
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5.9 __________________________________________________________________________
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6.0 INTRODUCTION
6.1 Theory
Oxy- acetylene welding is one of the oldest welding processes. Its use has declined
somewhat in popularity in recent years, but it is still widely used for welding pipes and tubes, as
well as for repair work.
Oxy-acetylene welding does not require electricity and is typically used for maintenance, in
body shops, and in the repair of small parts where other welding processes are too expensive.
Oxy-acetylene welding can be used to join iron, steel, cast iron, copper, brass, aluminum,
bronze and other metals. Often, dissimilar metals such as steel and cast iron, brass and steel,
copper and iron, and brass and cast iron can be joined with oxy- acetylene welding. Oxy-
acetylene welding equipment can also be used for preheating, cutting metal, case hardening,
annealing, soldering and brazing.
Oxy-acetylene welding uses the heat from the combustion of a mixture of oxygen and
acetylene (the fuel gas) to fuse base metals and filler metal together. This mixture produces
flame temperatures in the range of 5800°F to 6300°F, which can be used to weld a variety of
metals.
Oxy-acetylene welding processes are used with or without filler rod/metal. If filler rod/
metal is not used in the joint, the weld is autogenous. An autogenous weld is a fusion weld
made without filler rod/metal.
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4. JM101 MECHATRONIC ENGINEERING PRACTICE 1 GAS WELDING
7.0 PROCEDURES
7.1 Clean the surface of the work piece with wire brush.
7.2 Prepare the gas welding equipment.
7.3 Open the cylinder valve and set the acetylene regulator from 5 bar to 8 bar and for oxygen
from 8 bar to 10 bar.
7.4 Make sure the work piece is underlay to provide air space at the bottom of the welded
work piece.
7.5 Ignite and adjust the flame until producing oxidation flame.
7.6 Determine the angle of welding torch between 60° to 70°.
7.7 Heat the work piece surface for preheat purpose to avoid the work piece from warp.
7.8 Begin the welding work with forward welding technique.
7.9 Heat the work piece at one point until melt and move the welding torch to get enough
molten weld pool.
7.10 Dip the molten weld pool to get the penetration.
7.11 To get good penetration, control the molten weld pool so that it’s not too wide or too
small.
7.12 Make sure the distance between inner cone flame and molten weld pool is within 2mm to
4mm.
7.13 Repeat the process(7.6 to 7.12) for next weld pass until all part completely welded.
7.14 After completion, clean the work piece with wire brush.
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5. JM101 MECHATRONIC ENGINEERING PRACTICE 1 GAS WELDING
PROCEDURES DIAGRAM (with label)
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6. JM101 MECHATRONIC ENGINEERING PRACTICE 1 GAS WELDING
PROCEDURES DIAGRAM (with label)
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7. JM101 MECHATRONIC ENGINEERING PRACTICE 1 GAS WELDING
8.0 RESULT
Draw the work piece with the dimension.
9.0 DISCUSSION
9.1 How much should the cylinder valve be opened on an acetylene cylinder? On the oxygen
cylinder?
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9.2 What is a tip cleaner? When and why should it be used?
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9.3 Why is it dangerous to light a torch with match or a lighter?
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9.4 What type of protective clothing is commonly worn when oxy-acetylene welding?
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8. JM101 MECHATRONIC ENGINEERING PRACTICE 1 GAS WELDING
10.0CONCLUSION
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11.0 REFERENCES
11.1 B.J Moniz and R.T. Miller (2010).Welding Skills Fourth Edition. American Technical
Publishers. Orland Park, Illinois.
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11.3 ________________________________________________________________________
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9. JM101 MECHATRONIC ENGINEERING PRACTICE 1 GAS WELDING
PROJECT MARKING SCHEME
MARK(S) GIVEN MARKING MARK(S) MAXIMUM
ASSESSMENT CRITERIA
FACTOR OBTAINED MARKS
4 3 2 1 0
Uniform width and height of weld beads 4 16
Fine and even weld beads 4 16
Concave shape of weld beads 4 16
Penetration along the weld beads 4 16
Even starting and finishing 4 16
No leakage at weld beads parts 4 16
Clean and neat work piece 1 4
TOTAL MARKS 100
REPORT MARKING SCHEME
MARK(S) MAXIMUM
ASSESSMENT CRITERIA COMMENT
OBTAINED MARKS
Front cover 5
Apparatus/equipment and material 15
- list out and draw the diagram correctly
Safety and health 15
Procedures 25
- write the procedures in order and use
passive sentences
Result 5
- draw the work piece with dimension
Discussion
- Question 9.1 5
- Question 9.2 5
- Question 9.3 5
- Question 9.4 5
Conclusion 5
References 5
Report neatness 5
TOTAL MARKS 100
Lecturer’s Signature,
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Date :
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