In certain environments, the insulator metal parts deteriorate with time due to electrolytic corrosion. This is particularly true in coastal areas, tropical climates and many polluted areas. In order to extend the service life of the insulators installed in such environments, Sediver offers several solutions to improve protection against corrosion:

All Sediver ferrous metal fittings are hot-dip galvanised.
IEC 60383-1 requires a zinc coating mass of 600 g/m² - or 85 µm. In severe conditions, where this standard protection is known to be insufficient, Sediver offers enhanced protection of the cap and the pin by increasing the thickness of zinc from 85 µm to 110 µm.

In severely corrosive marine and industrial atmospheres, and in all DC applications, the galvanised coating on insulator pins may deteriorate over time and be followed by corrosion of the pin itself. To prevent this form of pin damage, SEDIVER supplies - when needed - pins with a corrosion retarding sleeve made of high-purity zinc.
(The catalogue designation which identifies the presence of a zinc sleeve is "YC" or "ZC").

Sediver has developed and patented a cap which is protected by a cast-on collar made of high purity zinc. Sediver recommends its use for all HVDC applications and for HVAC applications in very corrosive marine and industrial atmospheres.
(The catalogue designation which identifies the presence of a zinc collar is "ZD" )

Sediver has developed a special range of insulators dedicated to perform in tropical environment.
The figure represents typical toughened glass optimised insulators used in tropical areas subjected to heavy contamination: