Page 88 - CITS - Welder - Trade Practical

WELDER - CITS

The root gap is increasing from right end to the left end because the gap will get closed as the weld proceeds
towards the left end, due to expansion of the base metal.
Tack-weld the joint at equal intervals to hold them together, maintaining the alignment. (Fig 1)
Ensure that the
- distance between the tack-welds is 75 mm.
- length of the tack-weld is 6 mm.

Tack welds should be on the back side of the joint to be welded and in line with the joint.
Check the alignment after tacking, and reset, if the sheets are out of alignment. (Fig 2)

Fig 1 Fig 2

Welding: Keep free space under the joint for complete penetration. (Fig 3)
Start the weld at the right end of the joint. (Fig 4)

Fig 3 Fig 4

Weld a well fused uniform bead with complete penetration using leftward technique. (Fig 4)

Manipulate the blowpipe to maintain necessary motion to the blow pipe and the filler rod and the recommended
angle of blowpipe and the filler rod.
Maintain uniform travel speed and feed to the flame and the filler rod.

Maintain a keyhole which is a clear indication that the melting is taking place up to the bottom of the root of the
joint ensuring better root penetration. (Fig 5)
Clean the deposited bead using wire brush.
Inspect the quality of weld by:

- Checking the finish of the job
- Checking the alignment (remove distortion if required)
- Checking the uniformity of width and height of the weld bead in size (Fig 6)

71

CITS : C G & M - Welder - Exercise 14