Page 250 - CITS - Welder - Trade Practical

WELDER - CITS

- Mark the development on the pipe and cut accordingly.
- Deburr the cutting edges and file the edges.
- Clean the surface of the pipe if any oxide is found.

- Setand align the branch pipe with the main pipe at an angle of 90°.
- Tack-weld the joint with a 2 mm root gap to control distortion and to obtain penetration
- On Tee joint ,angle joints and cluster joints use a sequenceweldingtechnique.This prevents weld metal on
traction from pulling the pipe out of line. illustrate sone satisfactory sequence for aT-pipe assembly. When ever
possible, do all the welding in a down hand position. As in all pipe welding, the weld metal must be well fused
into the base metal. There must be good penetration and nounder cutting

- Manipulation of the torch during welding the’Tee’ joint should be correctly followed.
- Weld and complete the joint-clean
Note: Wear protective clothing.
• Tack-weld on both ends.
• Set the lap joint in a flat position.

• Deposit root run by using a 3.15mm dia. Medium coated M.S. electrode with 100-110 amps current.
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 a 4.00 mm dia. Medium coated M.S. electrode
with150-160amps welding current.
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 lap fillet weld for surface defects and size.

233

CITS : C G & M - Welder - Exercise 60