Page 89 - CITS - Fitter - Trade Theory

FITTER - CITS

• Artisanal Metalwork: Gas welding is utilized by artisans and craftsmen for creating custom metalwork,
including gates, railings, fences, furniture, and decorative elements. It allows for precise control over the
welding process, enabling intricate designs and fine details.
• Jewellery Making: Gas welding is used in jewellery making and metalworking for soldering, brazing, and
welding precious metals such as gold, silver, and platinum. It enables jewellers to create intricate and delicate
jewellery pieces with strong and durable joints.
• Agricultural Equipment Repair: Gas welding is employed in agricultural equipment repair for welding and
fabricating metal components, machinery parts, and farm implements. It provides versatility and durability for
repairing agricultural equipment subjected to heavy use and harsh conditions.
4 Oxy Acetylene welding and Cutting process:
The oxy-acetylene welding and cutting process, also known as oxy-fuel welding and cutting, is a versatile
and widely used method for joining and cutting metals. It involves the controlled combustion of acetylene and
oxygen gases to produce a high- temperature flame capable of melting and welding metals or cutting through
them. Here’s a breakdown of the process and the equipment involved:
1 Equipment Setup:
• Oxygen Pressure Regulator: Similarly, the oxygen pressure regulator is attached to the oxygen gas cylinder
and controls the pressure of oxygen gas supplied to the welding torch. It allows for precise adjustment of
oxygen flow rates.
• Gas Hoses: High-pressure gas hoses, color-coded for easy identification (blue for oxygen, red for acetylene),
connect the gas cylinders to the welding torch. These hoses deliver the gases from the cylinders to the torch
under controlled pressure and flow rates.
• Welding Torch or Blowpipe: The welding torch or blowpipe is the handheld device that mixes the acetylene
and oxygen gases in precise proportions and directs the resulting flame onto the workpiece. It contains valves,
tips, and nozzles for adjusting flame characteristics and welding parameters.

• Nozzles and Tips: The welding torch is equipped with interchangeable nozzles and tips of various sizes to
produce different flame sizes and shapes suitable for welding or cutting operations.
• Gas Lighter: A gas lighter or spark igniter is used to ignite the mixed gases at the welding torch tip, creating
a flame for welding or cutting.
2 Protective Clothing and Equipment:
• Protective Clothing: Welders must wear appropriate protective clothing, including flame-resistant garments
such as an asbestos apron, gloves, and long sleeves, to protect against heat, sparks, and molten metal
splatter.
• Eye Protection: Welding goggles or a welding helmet with a suitable shade lens are essential for protecting
the welder’s eyes from harmful UV radiation, intense light, and sparks generated during welding or cutting
operations.
• Respiratory Protection: In confined spaces or poorly ventilated areas, respiratory protection may be required
to prevent inhalation of fumes and gases produced during welding or cutting.
3 Consumables:
• Filler Rods and Fluxes: Filler rods and fluxes may be used in oxy-acetylene welding to fill gaps, provide
additional material, or protect the weld pool from atmospheric contamination. The choice of filler metal and flux
depends on the base metal being welded and the welding process.
4 Process Overview:
• Welding: In oxy-acetylene welding, the torch flame is directed onto the workpiece, heating it to the melting
point. The molten metal is then fused together, forming a weld joint. Filler metal may be added to enhance the
weld strength and fill gaps.
• Cutting: In oxy-acetylene cutting, the torch flame is used to preheat the workpiece to ignition temperature. A
jet of pure oxygen is then directed onto the preheated metal, causing it to react with the oxygen and form metal
oxides. The exothermic reaction generates additional heat, melting through the metal and producing a clean,
precise cut.

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CITS : CG & M - Fitter - Lesson 12