Page 157 - CITS - Welder - Trade Practical

WELDER - CITS

Job Sequence

• Cut the pipes to the given size.
• File pipe ends to be at right angle to the pipe axis.

• Grind the edges to 30 to 35° bevel maintaining 1.5 to 1.75 mm root face.
• Remove the burrs and rust from the pipe ends.
• Arrange the 2 pipes to form as a butt joint.
• Use a fixture or V profile of an angle iron to align pipes.
• Switch ‘on’ the machine and select a 3.15 mm ø electrode for tacking and the root run and set an 100 amps
current.
• Put 4 tacks at regular interval adjusting 2 mm root gap between the pipes using spacers.
• Ensure that each tack ends with a key hole.

• Check and ensure that the pipes are in line after tacking.
• Set 110 amp for a 3.15mmø electrode for root run.
• Deposit the root run in flat position by rotating the pipe.
• Welding using the keyhole technique ensures root penetration.
• Remove slag from the root thoroughly.

• Deposit the second and third run using a 3.15 mm ø electrodes i.e. the same as for the root run.
• Clean and inspect the joint.

Skill Sequence

Pipe joint on MS pipe ø50mm×6mm wall thick in overhead

rolled position

Objectives: At the end of this exercise you shall be able to
• prepare and weld pipe joint on MS pipe ø50mm×6mm wall thick in overhead rolled position.

Cut the pipes to the given size by a hacksaw.

Check the squares of the pipe end by using a try square. (Fig 1) and file the pipe end so that it is square with the
pipe axis.

Fig 1

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CITS : C G & M - Welder - Exercise 33 CITS : C G & M - Welder - Exercise 33