Page 96 - CITS - Welder - Trade Practical

WELDER - CITS

Job Sequence

• Prepare the job pieces as per drawing.
• Clean the edges and surfaces of the metal pieces.
• Set the job pieces as square butt joint with a root gap of 1.5 mm.

• Select the nozzle No. 5 and C.C.MS. filler rod dia. 1.6 mm.
• Set a gas pressure of 0.15 kg/cm2.
• Follow necessary safety precautions.
• Tack weld the sheets and check for uniform root gap and alignment.
• Weld the joint with a single run in horizontal position.

• Clean the welded area and inspect the weld for defects.

Skill Sequence

Weld square butt joint 2mm horizontal position (2G)

Objectives: At the end of this exercise you shall be able to
• prepare and weld square butt joint MS plate 2mm in horizontal position.

Position the crossbar of the positioner to the eye level. (Fig 1)

Adjust the pressure of oxygen and that of acetylene at 0.15 kg/cm2.
Set a soft neutral flame.
Tack-weld the job at both ends and at the centre with a root gap of 2.5 mm.
Fix the job on the crossbar of the positioner in horizontal position. (Fig 1)
Note : Ensure the job is in horizontal position at a convenient height.

Hold the blowpipe at 60° to 70° and the filler rod at 30° to 40° to the line of weld. Deposit the bead from the right
end of the joint by giving a circular motion to the blowpipe and proceed towards the left end.
Note : Ensure both edges melt equally and up to the root of the joint.
Check the weldment for correct profile with complete penetration.

Proper angle between the blow pipe, filler rod and the sheet surface is to be maintained (Fig 2). The filler rod is
added when the inner cone of the flame reaches the top edge of the joint. This will help in avoiding the excessive
melting of the bottom edge of the joint and will avoid sagging of weld metal.

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CITS : C G & M - Welder - Exercise 16