Post insulator is used as high-voltage insulating between discharge electrode system and ESP casing, and meanwhile supporting the weight of the entire discharge electrode system. A post insulator consists of the ceramic body and metal fittings at both ends which are cemented together with binder that can withstand high temperature. The cementing faces on a ceramic insulator body are knurling treated, and a high temperature withstanding elastic layer is interposed between the ceramic body end and metal fittings, and a buffer is also applied between them to prevent from loosening and to ensure mechanical strength.

The insulator is glazed white or brown on the ceramic part surface and the metal fittings are applied with anti-rusting paint.

The ceramic post insulator conforms to the Chinese standards of GB/T772-2005 ‘Technical specifications for high-voltage insulator’ and JB/T 5909-2010 ‘The ceramic insulator used in precipitator’, and the IEC series standard is also followed.

With different materials the ceramic post insulator can be used under the temperature ≤250℃ or ≤350℃ with the operating voltage ranging from 72kV to 120kV and a mechanical compressive failing load not less than 300kN.