The ability of SEDIVER Suspension Insulators to indefinitely withstand the effects of time and the elements is directly related to the structural purity of their glass dielectric shells, and to the permanent surface pre-stresses imparted by the SEDIVER toughening process. No other ceramic dielectric shell material possesses this ideal combination of desirable characteristics.

In the case of cap & pin dielectric materials - both porcelain and glass - their long term mechanical performance depends on their ability to resist the initiation and propagation of surface and/or internal cracks due to stress in service.
The electrical performance of these materials is similarly dependant on their structural consistency as internal discontinuity is the starting point of failure due to electrical stress concentration.

Because the first step of the glass manufacturing process is the total fusion of raw materials, the homogeneity and purity of glass structure is without comparison with other materials.

However, in order to maintain this purity level throughout the glass manufacturing process, it is primordial to master a wide range of parameters to eliminate inclusions in the glass shells.

Sediver, with more than fifty years of specialised experience in insulation, has achieved this goal by:

• Constantly monitoring all raw materials for correct chemical composition,
• Continuous metering of the raw material mixture,
• State of the art glass furnace design and operation, including specific refractory wall materials and automated control of internal atmosphere and temperature,
• Multiple thermal shocks testing of every glass dielectric shell after molding and toughening.