Acetylene is the primary fuel for oxyfuel welding. Oxyacetylene provides the highest flame temperature of the fuel gases, making it ideal for welding high-strength steels
. The equipment is portable and relatively easy to use. It comprises individual steel cylinders of oxygen and acetylene gases under pressure, each fitted with regulators and hoses that lead to the mixing chamber.
Welders can adjust the flame by changing the ratio of oxygen to acetylene, creating three flame settings: neutral, oxidizing, and carburizing. Most welding occurs with the neutral flame setting, meaning there are equal quantities of oxygen and acetylene. Increasing the oxygen flow rate produces an oxidizing flame while carburizing is obtained with a higher acetylene rate.
Specially designed safety valves between the hoses and the cylinder regulators keep the gas flowing in one direction, reducing the possibility of a hazardous flashback. And because acetylene is a volatile gas, it requires careful handling and specific storage procedures.
Even though acetylene is typically the most expensive of the fuel gases, oxyacetylene welding is the top choice of many beginners and part-time welders since it is a flexible and forgiving process.