Conventional accessories


Transformers breathe during the thermal contraction of the oil inside the transformer. Control that no humidity enters inside the transformer during this operation because moisture causes aging and outages. Choose our dehydrating breathers and assure moisture absorption through colored silica gel, which indicates the silica gel saturation. The operator identifies on-site when to replace the silica gel with new salt.

Contact us and get support with the product selection.

Why buy

  • Proven technology
  • Large installed base
  • Easy installation and easy maintenance on site


  • Oil-filled transformers with conservator
  • On-load tap-changers
  • Suitable for new installations and retrofits

Technical data at a glance

MaterialAll the external parts are resistant to transformer oils, salt fog and UV rays
Three types of installation environmentIndoor / OutdoorCorrosion class: C4-MediumRAL 7032
Tropical proofCorrosion class: C5-MediumGeomet coatings
Protection pipe materialGlass or Polycarbonate
Ambient temperatureFrom -40 °C to 80 °C (from -40 °F to 176 °F)
ConnectionAvailable with EN flange or with female thread
Adding flange for fixingStandard in the lower part for dehydrating breathers type 7 and 8
DesiccantColored, non-poisonous silica gel; the color changes from orange to green when absorbing humidity. To choose the right size for your transformer, please consult the selection matrix below
ProtectionStainless steel pipe protection against accidental blows; the opening allows visual inspection of the silica gel on site
Pressure load loss of air through the dehydrating breather0,003 kg/cm2 for in-let air; 0,005 kg/cm2 for out-let air

Selection Matrix

Features* Options
Breather typeQuantity of oil [t]**Silica gel volume [dm3]Silica gel weight [Kg]Corrosion protection C4-MediumCorrosion protection C5-MediumHydraulic closingMechanical closingPolycarbonate tubeGlass tubeFlange connectionFemale connection
E110 – 20.250.20xxxx
12 – 40.510.41xxxxxxx
24 – 80.970.78xxxxxxxx
38 – 142.872.3xxxxxxxx
414 – 207.255.8xxxxxxxx
520 – 4014.3711.5xxxxxxxx
640 – 6020.7516.6xxxxxxxx
760 – 8036.2529xxxxxx

* Available for the standard version

** The oil quantities assigned to size classes are oriented on normal European ambient conditions as given in EN50216-1, Table 1.
The values are intended to give guidance to the user: The proposed choice must take into consideration the real environmental conditions,
the thermal cycles due to the service conditions of the transformer and the maintenance cycle.

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