Glass insulators are devices used to support and insulate conductors; these insulators are made of glass.

Glass insulators are insulating devices used in power systems, primarily for supporting and fixing conductors, while also acting as insulation between the conductors and supports. A glass insulator is assembled from an iron cap, tempered glass components, and steel feet using cement adhesive. Before assembly, a soft gasket is placed at the top of the steel foot, and an asphalt layer is applied to the area where the inner cavity of the iron cap contacts the cement adhesive. The gasket and asphalt layer buffer damage that may occur when the insulator is subjected to thermal expansion and contraction. The tempered glass components provide insulation. Glass insulators are characterized by their small size, light weight, zero-value self-explosion capability, ease of testing, high mechanical strength, good arc resistance, excellent self-cleaning properties, and resistance to aging. Furthermore, the coating material offers advantages such as strong hydrophobicity, durable pollution resistance, low surface leakage current, and maintenance-free operation, making them widely used in various power lines both domestically and internationally. Disc-type suspension glass insulators are classified into six main categories: standard, anti-pollution, DC, pneumatic, awning, and ground wire types.

Glass insulators are mainly used for insulation and suspension of conductors in high-voltage, ultra-high-voltage, and extra-high-voltage AC and DC transmission lines.