Page 33 - CITS - Welder - Trade Practical

WELDER - CITS

• Scribe the circle of diameter 100 mm, using divider (Fig 1).
• Scribe the arc with centre A of radius 50 mm (Fig 1) cutting the circle, repeat with centre B to scribe the arc as
shown in Fig 1.
• Scribe the lines to join AC, CE, EB, BF, DF and DA as in Fig 2, using straight edge and scribes to farm
hexagon.

Fig 1 Fig 2

• Punch witness marks to complete the hexagon shape.
• Mark the triangle with in the hexagon as per the dimension shown in the drawing, and punch witness marks
to complete the triangle.
• Drill a hole of ø6mm on centre mark.
• Set the oxy-acetylene plant and cutting blowpipe for gas welting the geometrical profiles.
• Attach suitable nozzle for gas cutting, according to thickness metal to be cut.
• Adjust the gas measure of acetylene and cutting oxygen, according to the thickness of metal to be cut.
• Adjust proper cutting flame, and hold the cutting blowpipe at 90° (Refer skill sequence on 1.1.15).
• Start the gas welting from drilled hole to triangle line marked.
• Cut the profile on marked line to complete the triangle.
• Start the cutting from the edge of plate to the marked line of hexagon as required.
Note: Maintain correct speed and distance of nozzle while cutting.

• Close cutting oxygen and extinguish the flame on completion of cut.
• Clean the cut, after one job is cooled.
• Inspect the surface cut for uniformity.

TASK 3
• Clean the surface of metal to be cut.
• Mark and punch as per the profile shown in the drawing.
• Set the gas cutting plant with a cutting blow pipe.
• Attach the correct cutting nozzle according to thickness of the metal.
• Adjust the gas measure for the cutting.
• Adjust a proper cutting flame and has the blowpipe in proper position.
• Heat the metal surface at the starting point to bright red hot.
• Move the cutting blow pipe towards the other end following the punched line slowly and steadily.
• Maintain a correct speed and distance of the nozzle while cutting.
• Close the cutting oxygen and extinguish the flame a completion of the cut.

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CITS : C G & M - Welder - Exercise 04