Oxy-fuel welding and cutting

Oxy-fuel welding of metal is commonly called oxyacetylene welding since

The apparatus used in gas welding consists basically of an oxygen source and a fuel gas source (usually cylinders), two pressure regulators and two flexible hoses (one of each for each cylinder), and a torch. This sort of torch can also be used for soldering and brazing. The cylinders are often carried in a special wheeled trolley.

There have been examples of oxyhydrogen cutting sets with small (scuba-sized) gas cylinders worn on the user's back in a backpack harness, for rescue work and similar.

There are also examples of pressurized liquid fuel cutting torches, usually using gasoline. These are used for their increased portability.

Welding torch

The torch is the part that the welder holds and manipulates to make the weld. It has two valves and two connections, one each for the fuel gas and the oxygen, a handle for the welder to grasp, a mixing chamber (set at an angle) where the fuel gas and oxygen mix, with a tip where the flame comes out.

Cutting torch

A cutting torch is used to cut metal. It is similar to a welding torch. The most common fuel used for cutting torches is acetylene. Oxygen is combined with the acetylene in the torch, which produces a high temperature flame. The differences between a cutting torch and a welding torch are:

acetylene is the predominant choice for a fuel, or often simply gas welding. In gas welding and cutting, the heat needed to melt the metal comes from a fuel gas burning with oxygen in a torch.

Oxy-fuel cutting of metal is a similar process, using a different type of gas torch, called a blowtorch. (But, colloquially, many people also call a welding torch a blowtorch.) Here the metal is heated until it glows, and then a long lever on the torch is pressed to blow an excess of oxygen into the gas mixture, to blow and melt the metal with the resulting extra heat, much of which comes from the metal burning rather than from the gas burning. Sometimes a metal-cutting blowtorch is colloquially called a gas-axe or hot wrench.

Torches that do not mix pure oxygen with the fuel inside the torch, but burn it with atmospheric air, are not oxy-fuel torches and can be identified by their single tank. (Oxy-fuel welding needs two tanks, fuel and oxygen.) Most metals cannot be melted with such single-tank torches, so they can only be used for soldering and brazing, not welding. See also Blowlamp.

The apparatus used in gas welding consists basically of an oxygen source and a fuel gas source (usually cylinders), two pressure regulators and two flexible hoses (one of each for each cylinder), and a torch. This sort of torch can also be used for soldering and brazing. The cylinders are often carried in a special wheeled trolley.

There have been examples of oxyhydrogen cutting sets with small (scuba-sized) gas cylinders worn on the user's back in a backpack harness, for rescue work and similar.

There are also examples of pressurized liquid fuel cutting torches, usually using gasoline. These are used for their increased portability.   more from wikipedia