What liquid is used in transformers?

Transformer oil is most often based on mineral oil, but alternative formulations with different engineering or environmental properties are growing in popularity.

How do you add liquid to a transformer?

Transformers are normally shipped liquid filled. It should become necessary to refill a transformer, make sure all joints are tight and vent the tank to the atmosphere while filling.

 In order to prevent aeration, it is preferable to fill the transformer through the drain valve with a filter system.

Are transformers filled with liquid?

Today, most transformers are filled with mineral oil. 

This has been the case since the late 19th century, when chemist Elihu Thomson, 

whose company later merged to form General Electric, patented the use of mineral oil in transformers to help disperse heat from the core of a transformer in order to prolong its life.

Liquid transformer Dry type transformer Surge arrester Lightning arrester Distribution transformer Power transformer Paid mounted transformer High voltage switchgear Low voltage switchgear Skid mounted transformer Mother coil Silicone steel plate Single phase transformer Three phases transformer Liquid transformer Dry type transformer Surge arrester Lightning arrester Distribution transformer Power transformer Paid mounted transformer High voltage switchgear Low voltage switchgear Skid mounted transformer Mother coil Silicone steel plate Single phase transformer Three phases transformer Liquid transformer Dry type transformer Surge arrester Lightning arrester Distribution transformer Power transformer Paid mounted transformer High voltage switchgear Low voltage switchgear Skid mounted transformer Mother coil Silicone steel plate Single phase transformer Three phases transformer Liquid transformer Dry type transformer Surge arrester Lightning arrester Distribution transformer Power transformer Paid mounted transformer High voltage switchgear Low voltage switchgear Skid mounted transformer Mother coil Silicone steel plate Single phase transformer Three phases transformer Liquid transformer Dry type transformer Surge arrester Lightning arrester Distribution transformer Power transformer Paid mounted transformer High voltage switchgear Low voltage switchgear Skid mounted transformer Mother coil Silicone steel plate Single phase transformer Three phases transformer Liquid transformer Dry type transformer Surge arrester Lightning arrester Distribution transformer Power transformer Paid mounted transformer High voltage switchgear Low voltage switchgear Skid mounted transformer Mother coil Silicone steel plate Single phase transformer Three phases transformer Liquid transformer Dry type transformer Surge arrester Lightning arrester Distribution transformer Power transformer Paid mounted transformer High voltage switchgear Low voltage switchgear Skid mounted transformer Mother coil Silicone steel plate Single phase transformer Three phases transformer Liquid transformer Dry type transformer Surge arrester Lightning arrester Distribution transformer Power transformer Paid mounted transformer High voltage switchgear Low voltage switchgear Skid mounted transformer Mother coil Silicone steel plate Single phase transformer Three phases transformerLiquid transformer Dry type transformer Surge arrester Lightning arrester Distribution transformer Power transformer Paid mounted transformer High voltage switchgear Low voltage switchgear Skid mounted transformer Mother coil Silicone steel plate Single phase transformer Three phases transformer Liquid transformer Dry type transformer Surge arrester Lightning arrester Distribution transformer Power transformer Paid mounted transformer High voltage switchgear Low voltage switchgear Skid mounted transformer Mother coil Silicone steel plate Single phase transformer Three phases transformer Liquid transformer Dry type transformer Surge arrester Lightning arrester Distribution transformer Power transformer Paid mounted transformer High voltage switchgear Low voltage switchgear Skid mounted transformer Mother coil Silicone steel plate Single phase transformer Three phases transformer Liquid transformer Dry type transformer Surge arrester Lightning arrester Distribution transformer Power transformer Paid mounted transformer High voltage switchgear Low voltage switchgear Skid mounted transformer Mother coil Silicone steel plate Single phase transformer Three phases transformer Liquid transformer Dry type transformer Surge arrester Lightning arrester Distribution transformer Power transformer Paid mounted transformer High voltage switchgear Low voltage switchgear Skid mounted transformer Mother coil Silicone steel plate Single phase transformer Three phases transformer Liquid transformer Dry type transformer Surge arrester Lightning arrester Distribution transformer Liquid transformer Dry type transformer