Porcelain insulators design and construction has some requirements in the specifications, such as porcelain insulator color, surface finish, porcelain properties and so on.
All porcelain insulators shall be non-porous and pass the porosity test requirements detailed in Clause 25 of AS 2947.1
The raw material shall be milled to achieve maximum homogeneity and the particle size of the quartz and felspar shall not exceed 100 μm.
The type of porcelain is to be stated in Attachment 1. Where soft triaxial porcelain is to be supplied, the following microstructural features are required:
(a) A structure comprising mullite and quartz crystals in a glassy matrix.
(b) Reaction of the quartz crystals with the matrix so that the matrix becomes noticeably rounded and rims of high silica glass are evident around the quartz particles.
(c) Freedom from cracks which are not contained within glassy solution rims of the structure.
The minimum cross breaking strength of the porcelain shall be 70 MPa when determined by the method described in Appendix G of BS 1598.
Photographs of the shape, porosity density and size of porosity of the porcelain to be offered at a minimum magnification of 150 shall be supplied with the offer.
Further, photographs of the microstructure of the porcelain to be offered at a magnification of at least 1500 shall also be supplied with the offer.
Porcelain insulators Color
The glazing of porcelain insulators shall be smoke blue (T33) or light grey (N35) in colour in accordance with AS 2700 and of a uniform shade.
Details of any variation to these colours are to be supplied with the offer.
The surface of the insulator shall be smooth, uniform and moisture proof. It shall be unaffected by weather, ozone, acidic and/or alkali deposits. Further, the insulator surface shall be free from excessive dust, carbon, cement or other pollutants when supplied.
Porcelain insulator production