As shown in the illustrated flow diagram for a self-contained recovery unit designed for the recovery of refrigerants from high pressure appliances as defined by the EPA Clean Air Act rules, what is the functional purpose of the item labeled "FS2"? GS-RA-32 Illustration GS-RA-32: the U.S. Coast Guard has not released this illustration.

Correct Answer: Option D — It automatically transitions the recovery unit from the direct liquid recovery mode to the direct vapor recovery mode.

Self-contained high-pressure recovery units utilize specific pressure-actuated switching devices to manage phase transitions. Control switch FS2 automatically transitions the recovery unit from direct liquid recovery into direct vapor recovery once the liquid phase is depleted, protecting the compressor from slugging.