Silica Gel is used to remove the moisture in the air entering in to the transformer. During the breathing of the transformer air enters in to the transformer. This air makes contact with the hot transformer oil in the conservator and removes the heat by convection. Air entering in to the transformer should be free from moisture else the properties of transformer oil gets degraded. Therefore silica gel crystals are provided in the breather to remove the moisture content in the air Silica gel crystals will be in blue color initially and after absorbing moisture it turns to pink.