Page 253 - CITS - Welder - Trade Practical

WELDER - CITS

• Connect finally the Flow meter, Gas hose to the welding torch/gun.
• Ensure to avoid leakage at all connections so as to get correct pressure at the nozzle end. This could be
checked by using soap water solution.
• When used with correct gas flow rate a rapid cracking and hissing sound shall be heard.
• Too little flow results in porosity and too high flow rate creates turbulences and in turn contaminates weld.
Note : Wear protective clothing.

• Tack weld on both ends.
• Set the lap joint in a flat position.
• Deposit root run.
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 using electrode.
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 weld for surface defects and size.
Skill Sequence

Set up and monitor GTAW welding machine &
accessories Sequence

Ensure to use correct size of the sheet for welding.

Select aluminimum (95% AL and 5% Si) filler wire 1.6mmf.
Set the current and other parameters as per the Table given below.
Open the gas cylinder valve slowly.
Follow leftward technique.
The filler rod and torch are held at an angle of 10 to 150 and 70 to 80° to the line of weld.

Finish welding and ensure to fill the crater.
Brush the weld using SS wire brush and check for defects if any.
A table-I of the variables used when manually welding aluminium with the gas tungsten arc using AC and high
frequency.

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CITS : C G & M - Welder - Exercise 61