What are the standard steps in a power transformer oil filtration procedure?

Standard oil filtration includes baseline oil testing, safe isolation and grounding of equipment, connection of filtration hoses, coarse and fine particulate filtration, vacuum dehydration to remove dissolved moisture, degassing to remove air and fault gases, and continuous monitoring of temperature and flow. After processing, oil samples are taken to confirm BDV, moisture, acidity, and dielectric loss meet limits. The procedure ends with leak checks, valve restoration, and full documentation of results.