What is the complete oil filtering process for transformer maintenance?

The oil filtering process involves: 1) heating, 2) coarse filtration (?20 µm), 3) vacuum dehydration, 4) degassing, 5) fine filtration (5-1 µm), 6) BDV test, 7) vacuum filling. Fluidex systems automate this process and include sampling ports for DGA and moisture testing.