Link insulator is used between the discharge electrode framework and ESP casing functioning as connecting and high-voltage insulating. By its own structure it is divided into two types: pure ceramic insulator and combined insulator.

A combined 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 or sanding 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.

No metal fittings for pure ceramic insulator type. The insulator is glazed white or brown on the ceramic part surface, and the metal fittings are applied with anti-rusting paint for the combined insulator type.

The ceramic link 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 link insulator can be used under the temperature ≤250℃ or ≤350℃ with the operating voltage ranging from 72kV to 120kV and the tensile failing load not less than 15kN.