Page 230 - CITS - Fitter Trade Pactical - Volume - 2

FITTER - CITS

Inspection of bevel cut: Clean the slag if sticking to the cut surface by a chipping hammer and wire brush and
inspect for any gas cutting defects.
GOOD QUALITY is shown by excellent top edge and extremely smooth cut face. The cut part is dimensionally
accurate. (Fig 13)

Fig 13

POOR QUALITY results in gouging which is a most common fault. This is caused either by excess speed or too
low a preheat flame. (Fig 14)

Fig 14

Oxy-acetylene machine cutting (straight, bevel, circle and
profile) (TASK 2)

Objectives: At the end of this exercise you shall be able to
• assembly of the portable cutting machine
• set the gas pressure to the size of nozzle
• cut the profiles by portable cutting machine.

The assembly of the machine, the use of templates or systems of reproduction, the position of the work, the speed
range and cutting nozzles vary according to the type of the machines.
Assemble the accessorises like cutting head for straight and bevel cutting with the cutting machine. (Fig 1)

Select the 1.2mm size of the cutting nozzle for 10mm thick plate.
Set the correct gas pressure of 0.15kgf/cm2 for acetylene and 1.4 to 2 kgf/cm2 for oxygen for 1.2mm size nozzle.

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CITS : C G & M - Fitter - Exercise 54