One of the methods for connecting metal parts to each other is gas welding, in which the welding process is carried out by heating and melting the edges of the metals being joined. It is produced using a welding flame formed as a result of the combustion of acetylene in a directed stream of oxygen. Also for these purposes, hydrogen, kerosene, gasoline and other combustible gases are used. The flame temperature as a result of the combustion of these gases reaches a temperature of 3050–3150 ° . In gas welding, the gap between the edges of the parts to be joined is filled with a filler wire, which fills this gap when melted in a flame.
Gas welding is performed using special equipment consisting of gas storage cylinders
, a reducer with two pressure gauges (low and high pressure) designed to regulate the gas supply during welding, as well as a torch and hoses for supplying gas to the burner from the adjustment gear.
Gas welding is used in industry for joining (welding) structures made of steel and some non-ferrous metals, including brass and cast iron, having a thickness of not more than five millimeters. Also, gas welding is applicable for surfacing, soldering and other repairs. Welding of metals of greater thickness is carried out using
electric arc welding. It is worth noting that gas
welding of metals is ineffective in comparison with electric arc.
Metal cutting is carried out with an oxygen stream using torches or special torches. The main difference between them and gas welding burners is that they have two oxygen jets - one for heating the metal, the other for blowing molten metal at the cutting sites. The torches differ in the design of the nozzle (mouthpiece), which are divided with respect to the location of the heating flame and the cutting jet by the stepwise arrangement of the nozzles, as well as the subsequent and concentric ones. They are also divided by the type of fuel used. There are cutters for hydrogen, acetylene, light gas, hydrogen, etc.
The metal cutting process is as follows: at the point of cutting start, the metal is heated by a heating stream to white, which corresponds to about 1000 ° C, after which the metal is partially burned or blown out at the cutting site. When cutting, it is very important to “hold” the melting temperature of the metal, for which the optimal option for feeding the cutting jet is selected. It is used for cutting iron, low carbon and low alloy steels.
Due to the fact that gas welding and metal cutting are production processes that require certain skills on gas welding equipment and knowledge of safety measures when performing hot work, it is necessary to attract qualified workers who have received special training for this type of work. Careless handling of equipment, as well as neglect of safety measures, can lead to serious consequences.