What Are the Common Drying Methods for Transformers?

What Are the Common Drying Methods for Transformers? The following are common drying methods for transformers such as H Class Dry Type Transformer for your reference: (1) If the transformer drying chamber such as the Dry Type Cast Resin Transformer is not evacuated, the vent hole should be opened on the tank cover or the moisture should be released by the throttle hole. (2) When heating with oil, the insulation layer should be installed outside the transformer tank such as