What sound typically accompanies a flashback?

The sound that typically accompanies a flashback is a hissing sound. This sound is often associated with high-temperature processes, like brazing or soldering, where the melting of the filler metal creates rapid vaporization of residual contaminants or flux. The hissing can indicate that the metal is being heated to its melting point and that the process is occurring smoothly, allowing the brazing metal to flow and properly fill the joint. This sound serves as a cue for the operator that the correct temperature is being reached and maintained, which is crucial for achieving a strong bond in the brazing process. Understanding these auditory signs is important for ensuring successful brazing and preventing potential failures in the joint.