Air contains a certain amount of moisture content. Thus, the proper working mechanism of a breather transformer depends on the moisture content in the air as the high amount of moisture can cause changes to the dielectric strength of the oil. Hence, silica gel are used for proper functioning of the breather transformer. The main function of silica gel is to control the amount of moisture available within a breather transformer. They are used to prevent any extra moisture from entering the transformer which may bring forth many unnecessary damaging effects to the transformer. The silica gels are very inert materials, non-toxic, DMF free, non flammable and will not corrode other materials. They are available in either orange or blue in colour with the weight of 12.5 kg per tin.
Silica gel (blue) turns light blue colour when it first comes in contact with any moisture and its colour will gradually change to light pink which indicates that it filled and can no longer absorb any more moisture. The colour changes from blue to light pink alerts workers/operators that replacement or regeneration of the silica gels in the breather transformer is needed. The silica gel (orange) functions the same as silica gel (blue). The only difference is that it changes colour from orange to dark green when it is filled with water.