Page 27 - CITS - Welder - Trade Theory

WELDER - CITS

Oxy-acetylene gas cutting of metal - cut ability, cutting

parameters

Objectives: At the end of this lesson you shall be able to
• explain of the oxy-acetylene cutting equipment
• describe the principal oxy-acetylene cutting
• describe the cutting parameter and metal cut ability.

Introduction
Oxy-Acetylene Gas Cutting is a widely used method for cutting metals, offering versatility and efficiency in various
industrial applications. It involves the use of a mixture of oxygen and acetylene gases, which are ignited to create
a high - temperature flame capable of melting and severing metal
Principle of gas cutting

When a ferrous metal is heated to red hot condition and then exposed to pure oxygen, a chemical reaction takes
place between the heated metal and oxygen. Due to this oxidation reaction, a large amount of heat is produced
and cutting action takes place.
Cutting torch
Different that regulator blow pipe it has an additional level for oxygen cutting
i Cutting tips is made with orifice in the centre surrounded by smaller five holes
ii Different types of cutting tips also available

Parameters

Cutting nozzle size-m Thickness of plate.mm Cutting oxygen Pressure kgf/cm 2
0.8 3-6 1.0-1.4
1.2 6-19 1.4-2.1

1.6 19-100 2.1-4.2
2.0 100-150 4.2-4.6
2.4 150-200 4.6-4.9
2.8 200-250 4.9-5.5
3.2 250-300 5.5-5.6

Application
- Low cost equipment
- Basic equipment suitable for cutting, gauging and other jobs such as welding and heating.
- Portable, suitable for site work.
- Manual and mechanized operations.

- Mild and low alloy steels (but not aluminum or stainless steel).
- Wide range of thickness (typically from 1- 1000mm).
Common defects
• Extremely slow cutting speed

• Tip too close the job

14

CITS : C G & M - Welder - Lesson 4&5