There are many types of insulators can be used on high voltage overhead transmission lines, including tie top composite line post insulators, which also called pin type insulators transmission lines.

Pin type insulators transmission lines specifications:
Composite Pin type insulator transmission lines have new wide top conductor grooves that meet ANSI standards and provide for all popular conductors up to 1-1/2" in diameter.
Top and neck are designed for either wraplock ties or standard tie wire conductor attachment.
Maximum rod diameter: 101.2 mm (4") up to 50 kNm
Flexible leakage path up to 55 mm (2.16”) / kV
Utilized in braced post assemblies
Special designs including string assemblies
Manufactured in accordance with the standards: IEC 61952, ANSI C29.17, ANSI C29.18

All of pin type insulators transmission lines have the advantage of small size, light weight, suitable for different environments, especially in the high polluted areas, and can perform very good electrical withstand quality.

All kinds of pin type insulators transmission lines should not fail due to environmental and electrical conditions of the occurrence of various electrical and mechanical load, otherwise composite pin insulators will not produce a significant role, and will directly harm the use and operation of the entire line and working lifespan.