What may occur if the acetylene flame burns without enough oxygen?

When acetylene burns without enough oxygen, it results in a sooty flame. This occurs because the incomplete combustion of acetylene produces carbon particles, which appear as soot. The hydrocarbon components of acetylene combine with insufficient oxygen, preventing them from fully oxidizing to carbon dioxide and water. Instead, carbon is released, leading to the characteristic yellow or sooty appearance of the flame.

A sooty flame not only indicates inefficient combustion but also suggests that the flame temperature may not be at its optimal level for cutting or welding, as the excess soot can interfere with the welding process and compromise the quality of any joints made. Moreover, this situation signals a need for adjusting the oxygen supply to ensure proper combustion and improve safety measures, since a sooty flame can also lead to potential hazards, such as fire risks due to unburned gases.