How does a transformer oil dehydrator remove moisture and gases?

A transformer oil dehydrator typically combines heating, filtration, and vacuum processing. Oil is warmed to reduce viscosity and release dissolved water, then passed into a vacuum chamber where low pressure causes moisture and dissolved gases to evaporate. Demisters and condensers remove the extracted vapors, while fine filters capture particles. Some systems add degassing stages to reduce air and fault gases. The result is lower moisture ppm, improved BDV, and reduced gas content, which strengthens insulation reliability and improves cooling performance.