Page 33 - CITS - Welder - Trade Practical
P. 33

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
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