Page 208 - CITS - Fitter Trade Pactical - Volume - 2

FITTER - CITS

The gas mixture from the blowpipe consists of oxygen and acetylene in equal volumes.
To adjust the oxidising flame, add more oxygen.
The white cone will become short and sharp.
The flame will produce a hissing sound and will have a short length. (Fig 5)

Fig 5

To adjust a carburising flame, adjust the flame to neutral and then add acetylene.

The white cone will become long, surrounded by a feather-like portion.
The flame will burn quietly and have more length. (Fig 6)

Fig 6

Extinguishing the flame
To extinguish the flame, close the acetylene valve (blowpipe) first and then the oxygen valve.
Shutting off the plant
At the end of the work, shut off the plant as stated below.
Close the acetylene cylinder valve.

Open the blowpipe acetylene valve and release all pressure.
Release the acetylene regulator pressure adjusting screw.
Close the blowpipe acetylene valve.
Repeat the above four steps for shutting off oxygen also.

Fusion runs without filler rod in flat position by gas

(TASK 2)

Objectives: At the end of this exercise you shall be able to:
• hold the blowpipe and flame in correct position to obtain proper fusion of metal
• make fusion runs without filler rod to produce uniform beeds
• visually examine the quality of fusion beeds.

Fusion runs
Homogeneous joints are produced in gas welding by melting and fusing the metal edges with the help of a gas
flame.

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CITS : C G & M - Fitter - Exercise 54