ABSTRACT
To appreciate the importance of safety one must fully understand the consequences of mixing
fuels with either air or pure oxygen. Explosive gases are mixtures of two reactants-oxygen
and a fuel gas-within the limits of inflammability; but some gases such as ozone, acetylene,
and hydrazine are by themselves explosive. The propagation of a combustion wave through
an explosive gas occurs when initiated by a source of ignition. When a flow of oxygen and
hydrogen or acetylene is properly adjusted, the flow of explosive gas mixture is maintained
forming a steady, brilliant luminous cone. When the flow of gas mixture is throttled to the
flash back point, however, the combustion wave enters the gas mixing chamber and develops
into a detonation wave evidenced by an explosive sound. This event does not occur when the
mixture is sufficiently diluted with either oxygen or fuel gas. Operators of oxyflame cutting,
welding, or flame-hardening often experience such flashbacks.
