Transformer Desiccant Breathers are filled with self-indicating silica gel desiccant which changes color from blue to pink as it becomes saturated with water vapor.  They are designed to enable the quick and easy replacement of the desiccant charge.  When the bottom half of the desiccant is pink, the charge should be replaced.  Now that the old type oil-seal has been replaced by inward and outward relief valves, the replacement of the desiccant charge is the only maintenance activity necessary.

Replacement of blue silica gel is available in 25 kg drums (standard packaging) or smaller can sizes.