Air Dehydrating Breathers for Power Transformers
Single body / hydraulic valve models
1. GENERAL INFORMATION
Air dehydrating breathers are transparent hollow cylinder tubes which contain chemically pure silicium salt (silicagel) with
coloured indicator. The air breathed inside the transformer due to the thermal contraction of the oil mass, passes through
the silicagel.
The silicagel absorbs the humidity, indicating the saturation degree by changing colour as follows:
ORANGE silicagel completely dry
GREEN silicagel saturated with humidity
The salt contained in the breather, when saturated, may be easily removed and regenerated by heating it, inside a
ventilated oven, at 120° – 150°C, until the colour becomes orange again.
The specific property of the silicagel is its high absorption power of humidity. This is total until the salt has absorbed water
for about 15% of its weight, and saturation is reached when the salt has absorbed water for 30 to 40 % of its weight.
2. TECHNICAL FEATURES
The upper and lower parts are made in a non-porous corrosion-proof aluminium alloy casting. The hollow cylinder is
made of Plexiglas (upon demand in glass) and it is protected by a stainless steel cylinder, with windows which allow the
visual control of the silicagel colour.
In the bottom side of the breather, an hydraulic valve prevents continuos air contact with the silicagel and allows the air to
pass in both direction (inlet or outlet) only when there is pressure deficiency or excess inside the transformer.
Pressure values for air passage into the dehumidifier are:
0.003 kg/cm2 inlet , or 0.005 kg/cm2 outlet
The hollow container and the hydraulic valve are separated by a drilled plate with a labyrinth system, which have the
double purpose of diffusing inlet air uniformly, and of avoiding that any salt dust may damage the closing system.
Download full catalogue: breathers-ve-series-full-catalogue.pdf