What is "flash-gas"

In refrigeration, flash-gas is refrigerant in gas form produced spontaneously when the condensed liquid is subjected to boiling. The presence of flash-gas in the liquid lines reduces the efficiency of the refrigeration cycle. It can also lead several expansion systems to work improperly, and increase superheating at the evaporator. This is normally perceived as an unwanted condition caused by dissociation between the volume of the system, and the pressures and temperatures that allow the refrigerant to be liquid. Flash-gas must not be confused with lack of condensation, but special gear such as receivers, internal heat exchangers, insulation, and refrigeration cycle optimizers may improve condensation and avoid gas in the liquid lines.