Page 295 - CITS - Welder - Trade Practical

WELDER - CITS

- Many different energy sources can be used for welding including a gas flame (chemical), an electric arc (electrical),
a laser, an electron beam, friction, and ultrasound.
- While often an industrial process, welding may be performed in many different environments including in open
air under water, and in outer space
- Welding is a hazardous undertaking and precautions are required to avoid burns, electric shock. vision damage,
inhalation of poisonous gases and fumes, and exposure to intense ultraviolet radiation.

Note: Wear protective clothing.
• Tack-weld on both ends.
• Set the lap joint in a flat position.
• Deposit root run by using a 2.4 mm dia. Tungsten electrode with 60 90 amps current.
Note: Ensure an electrode angle of 45° with the fillet corner and 80° with the welding line.
• Remove the slag with a chipping hammer and clean with a wire brush.

• Use tongs to hold the job.
• Wear chipping goggle for the protection of eyes.
• Deposit the final covering run with a weave motion coated M.S. electrode with150-160amps welding current.
Note: Prevent the upper edge of the plate from melting off.

• Remove the slag from the final weld and clean thoroughly.
Note: Use a weld gauge to check the fillet size.
• Inspect the lap fillet weld for surface defects and size.

Skill Sequence

Make Square butt joint on Tube welding on M.S. tube metals

in rolled position by GTAW and monitor the same

Objectives: At the end of this exercise you shall be able to
• make Square butt joint on Tube welding on M.S. tube metals in rolled position by GTAW and monitor the same.

Setting and tacking the lap joint

Set the butt joint with an overlap of 25mm.
The overlap may vary based on the plate thickness.
Tack-weld on both ends. Ensure the 2 lapping sur-faces are perfectly cleaned and they contact each other
properly.
Set the joint in a flat position using angle iron.
Welding the butt fillet joint in flat position
Deposit root run with 100-110 amp current.
Maintain 80° angle to the line of the weld and 45° between the weld faces.
Maintain a short arc to get uniform fusion and root penetration.

Note: Avoid side-to-side movement of the electrode.
Deslag and clean the root bead thoroughly.

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CITS : C G & M - Welder - Exercise 75