How is transformer oil recovered and reused after treatment?

Used oil is recovered by draining into clean, labeled containers, then processed to remove water, gases, acids, and particles. Typical treatment includes vacuum dehydration, filtration, degassing, and sometimes adsorption or clay treatment. After treatment, the oil is re tested against required specs (BDV, moisture, acidity, IFT, DDF, DGA baseline). Only oil that meets the target standard and is free of prohibited contaminants (like PCBs where applicable) is reused.