Oxyfuel torches use a mixture of oxygen and fuel gas to weld and cut metals. The oxyacetylene torch is one of the most common types of oxyfuel torches. It uses a fuel called acetylene, which is the fuel of choice for most standard cutting and welding jobs. When mixed with oxygen, acetylene makes a constant and very hot flame that can be used to precisely cut or melt metal.
The process of oxyfuel welding was created in 1903 by a pair of French engineers, Edmond Fouche and Charles Picard. They created a torch that consisted of a nozzle, a mixing chamber, and two tubes. One tube carried a fuel, such as acetylene, while the other carried pure oxygen. Oxygen and fuel mixed in the chamber and were released from the nozzle at a temperature much hotter than could previously be reached.
The extra heat comes from the pure oxygen mixed with the fuel. The air on Earth actually has a concentration of only about 21 percent oxygen, with 78 percent nitrogen and tiny amounts of other elements making up the extra percent or so. An acetylene flame burns at about 4m500 degrees Fahrenheit (2,500 Celsius) if mixed with common air. If acetylene is mixed with pure oxygen as in an oxyacetylene torch, the resulting flame will be up to 6,300 degrees Fahrenheit (3,480 Celsius).
This extra heat allows the operator of an oxyacetylene torch to create clean, controlled cuts by heating only the thin strip of metal that needs to be cut. An oxyacetylene torch can also be used for welding. When welding with an oxyacetylene torch, the flame is used to produce molten metal along the edge of two work pieces. The pieces are then joined using a filler metal. As the metals cool, they create a strong seam.
Acetylene is the hottest burning of the common fuel gases, which is why it is useful for welding. It is also highly unstable. The pressure of the gas must be controlled by a regulator at all times because acetylene will explode if it reaches a pressure higher than 15 pound per square inch. To avoid this, acetylene tanks are packed with porous materials and acetone.
An oxyacetylene torch should be operated only by a trained professional wearing proper safety gear. Due to the high temperatures and molten metal, oxyacetylene torches can be dangerous if not used correctly. Operators generally wear goggles or face shields to protect their faces and heavy gloves to protect their hands.