Page 199 - CITS - Fitter Trade Pactical - Volume - 2

FITTER - CITS

Avoid using any other source of fire other than the spark lighter.
Point the blowpipe in a safe direction in the open space, away from you and others.

Increase the acetylene till the black smoke disappears. (Fig 18)

Fig 18

Observe the flame and add oxygen by opening the oxygen control valve of the blowpipe. Now a bright white cone
starts appearing at the tip of the nozzle (Fig 19)
Fig 19

Square butt joint in flat position by gas (TASK 4)

Objectives: At the end of this exercise you shall be able to:
• set and tack the workpieces in alignment for a square butt joint
• produce a uniform and well penetrated bead on an open square butt joint in a flat position
• visually inspect the completed joint.

The requirements of a good welded joints are:

The joint must be in correct alignment (distortion free)
The weld must be well fused, well penetrated, uniform in width and height, of correct size and free from internal
or external faults.

Setting and tacking
Set and tack the job-pieces in correct alignment with a proper gap and for distortion allowance. (Fig 1)

Fig 1

184

CITS : C G & M - Fitter - Exercise 53