CONTENTS

• Introduction

• Materials and Methods

• Discussion
1. General Safety precautions followed in a welding shop
2. Characteristics of oxyfuel, arc and spot welding
3. Applications of oxyfuel, arc and spot welding in Sri Lanka

• Reference

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INTRODUCTION

Fabricating materials, such as metals or thermoplastics, involves welding. This is done by coalescence.
Usually, the workpiece is melted while a filler material is added. Through this activity, we can increase
our understanding of the welding process, its tools, and the purposes for which they are used, among
other things. We can also gain professional experience about welding by participating in this practical

Until the end of the 19th century, the only welding process was forge welding, which blacksmiths had
used for centuries to join iron and steel by heating and hammering. Arc welding and oxyfuel welding
were among the first processes to develop late in the century,

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MATERIALS AND METHODS

OXY FUEL WELDING

Tools needed: Welding Torch, Oxygen and Acetylene cylinders, Pressure regulators, Press gaugers,
Rubber hoses, Safety suits.

• All necessary equipment was first checked to make sure it was connected correctly and in an
usable condition.
• Next, the items that were to be welded were placed on the refractory bricked hearth.
• After that, the oxygen and acetylene valves were partially opened, and the torch was lighted
using a lighter.
• Once the workpiece's two edge points had been fully welded with the help of a torch and filler
rod, the workpiece was finished being completed.

ARC WELDING:

• All necessary equipment was first checked to make sure it was in good working order and was
correctly connected.
• The transistor then adjusted the appropriate valve for the current flowing through the wires.
• After that, the workpieces were put on the table, and the electrode's setup was evaluated by
seeing if a spark was produced when it made contact with the welding table.
• The workpiece was welded after donning the safety helmet if the system's settings were correct.

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SPOT WELDING:

Tools Needed: Spot welder, Safety suit

• First it was ensured that all components relevant to the practical were ready and at usable
condition.
• The spot was Turned ON.
• The workpieces were kept to their combination which they look after welding.
• Then the workpieces were kept between the two electrodes of the spot welder.
• The paddle of the welder was pushed and held until a small spark came out from where the
electrodes and workpiece touched.

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DISCUSSION

GENERAL SAFETY PRECAUTIONS FOLLOWED IN A WELDING SHOP

• Every person who interacts with welding work must wear safety suits.
• All flammable materials, including cotton, oil, gasoline, and others, must be taken out of the
welding area.
• The pressure of the gas cylinders, specially on oxyfuel welding are double checked whether
they are in their standard states.
• A suitable fire extinguisher is kept in the welding area all the time.
• The welding is performed in a well-ventilated area.

CHARACTERISTICS OF OXY-FUEL, ARC AND SPOT WELDING.

Oxy-Fuel Welding Arc Welding Spot Welding

Uses oxygen and acetylene as Uses an electric Arc to weld. Uses the heat obtained from
main components in welding. resistance to electric current.

Must use a filler rod The filler rod is the electrode. Welded by melting the
simultaneously with the No need to use it separately. workpieces. No need for filler
welding tip. rods.

Need skill power to do the task Needs skill power to do the task Need of skills power is
well. well. somewhat less than the others.

Large variety of material can be Large variety of material can be Some materials need special
welded. welded. preparation for making the spot
welding.

Less Cost. High initial Cost. Less initial cost.

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APPLICATIONS OF OXY-FUEL, ARC AND SPOT WELDING IN SRI LANKA.

Both everyday and industrial applications of welding are prevalent in Sri Lanka. These applications

involve a variety of welding techniques. However, oxy-fuel welding, arc welding, and spot welding are

the most used types of these. There may be one welding process that works for some applications and

two or more welding procedures that work for others. Depending on the application, we employ a

certain method.

APPLICATION OF OXY-ACYTYLENE WELDING

This method is mainly used to weld thin sheets. So, we can make equipment which are used in both

industry and home such as cups, small monuments etc. by oxy-fuel welding, because of its minimal

dilution with the base material. And oxy-fuel is also used to weld tubes and small diameter pipes

because it can be used in a variety of applications. We can see most of the metallic bathroom fittings

are made with high technological methods of oxy-fuel welding. And small metallic tubes which are

distributing water and which are used in laboratories are also weld by using oxy-fuel welding, in the

factories in Sri Lanka.

APPLICATION OF ARC WELDING

This method is also used very commonly in industrial work. We can see that there are many types of

arc welding. Some of them are listed below.

Short Arc: When using ferrous, it was to be between 0.5mm and 2.6mm in thickness. Application

for pipe industry.

Globular Arc: When using ferrous, the thickness has to be between 3mm and above. Commonly used

for law quality welding.

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Spray Arc: When using ferrous it is recommended the thickness is 5mm and above. It is

applicable for flat position, horizontal position, vertical and overhead filtering and

grooving. When using nonferrous materials it is used for fill passing.

High power Arc: As this is a very high power arc, it is only used in automated welding systems. This

method is used for larger joint types in Sri Lanka such as ship building, machine

construction, steel structuring etc.

APPLICATION OF SPOT WELDING

This procedure is also known as "resistance welding." Because it is simple to use and very inexpensive,

this approach is also used in modern industries. It is mostly utilized in Sri Lanka's train carriage, railway

maintenance, and automotive supply and repair sections. It is also primarily used in the food and

beverage industry. Open spot welding is typically used by producers when packaging food. We can see

that this technology is being used, particularly in sheet welding. Additionally, medical equipment is

made via spot welding.

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