Welding

Gas welding, also called oxyfuel gas welding (OFW), refers to a group of welding processes that use gas as the source of heat energy. Oxyacetylene and oxyhydrogen are two types of fuel gases used. Acetylene is commonly used for welding because, when combined with oxygen, the flame temperature can reach 5,600°F (3,093°C), the highest temperature produced by any fuel gas-oxygen combination. A filler metal rod may or may not be used with this type of welding process. The fuel gas and oxygen are contained in separate pressurized tanks or cylinders. Specially designed hoses run from the gas cylinders and connect to the welding torch. The welding torch has valves that control the amount of incoming gases, and a mixing chamber where the gases are mixed. The blended gases flow to the tip of the torch where the flame is ignited by a torch lighter, usually a flint and steel sparklighter. After the flame is lit, it must be adjusted until the correct balance of gases is achieved (a neutral flame). Oxyfuel gas welding was the primary welding process during the first part of the twentieth century. As newer methods of welding and new materials were developed, other, more suitable, welding processes replaced the oxyfuel gas process. Currently, the oxyacetylene process is used for braze welding, brazing, and soldering.