My understanding of Purgatory is that we need a purification before enjoying the Beatific vision; we must be perfected. If Satan had the imperfection of pride, how could he have been given access to the Beatific Vision?
Satan never had the beatific vision. None of the angels who fell did. The angels who chose to remain loyal to God received the beatific vision.
I believe that theologians speculate that the angels were given a preview of the incarnation and were given a choice to serve or not to serve. 1/3 of the angels, who found the idea of serving a lesser creature repugnant, rebelled.
Marcus is correct, the angels did not behold the Beatific Vision prior to their decision to rebel against or accept God. It is believed, however, that they did have Sanctifying Grace just as Adam and Eve did in the Garden.
Perception of the Beatific Vision renders the will incappable of future sin.