TABLE OF CONTENTS The first successful oxy-acetylene welding equipment was developed in France at the turn of the century (1901 3). The equipment was introduced to the commercial industries a year later and it immediately proved successful. Acetylene was first discovered in 1836, but was not produced successfully on a commercial basis until many years after this when the use of calcium carbide was first discovered. Oxygen was discovered many centuries ago, but its preparation on a commercial basis was not started until 1892.
Gas welding processes are so called because the welding heat is provided by a flame produced by the combustion of a mixture of gases. A variety of gases are used commercially, but an oxy-acetylene mixture is the most common because of its high flame temperature and because the gases are convenient to handle.
Oxygen forms 20 per cent of the atmosphere, the rest being nitrogen and a small percentage of rare gases such as helium, neon and argon. To obtain the oxygen in a state that makes it usable for welding, it is necessary to separate it from the other gases. Oxygen is produced commercially either by the electrolytic process or by a separation method known as the liquid-air process. Unlike oxygen, acetylene is not a natural but a manmade gas. It is a hydrocarbon gas produced by the action of water on calcium carbide. Acetylene is a colourless gas with a very distinctive nauseating odour. It is highly combustible when mixed with air or...
