Page 165 - CITS - Welder - Trade Practical

WELDER - CITS

Job Sequence

• Ensure the correct size of pipes are used.
• Prepare development for 45° branch on a drawing sheet.
• Cut and paste it on the pipes.
• Punch marks the profile of the development on both pipes. Cut the branch pipe along the punch marked profile
and file it. Cut the profile marked on the main pipe by gas cutting and file it.
• Deburr the gas cut edges and file the edges.
• Clean the surface of the pipe to remove any oxide and other contaminants.
• Set and align the branch pipe with the main pipe at an angle of 45°.
• Select no. 7 nozzle, ø3mm CCMS rod and use neutral flame with 0.15 kg/cm² pressure for both gases.

• Follow necessary safety precautions.
• Tack-weld the joint at 4 places with 45° intervals and with a 2 mm root gap to ensure root penetration.
• Ensure the tacked pipe “Branch” joint is positioned properly to make it convenient to manipulate the blow pipe
and filler rod without any obstruction.
• Weld the joint by manipulating the blow pipe and filler rod without rotation of the pipe.
• Maintain keyhole throughout the welding and give side to side motion to the blow pipe to ensure good root
penetration and fusion of both the edges of the joint.
• Complete the weld in 4 sectors 1, 2, 3 and 4 along the curved joint using leftward technique.
• Take care to properly fuse the crater of the previous sector welded with the starting of the new sector.

Note: Avoid excess penetration.
• Clean the weld and inspect the weldment for defects.

148

CITS : C G & M - Welder - Exercise 35