The design of tempered glass insulators is a clever combination of material technology, mechanical engineering, and electrical insulation technology. Its structural characteristics directly determine its reliable advantages of "high strength, zero self explosion, and maintenance free".
1. Core insulation component: tempered glass umbrella tray
Material essence: Made of high-purity silicate glass, it has excellent chemical stability and weather resistance, does not age, and its electrical properties (dielectric strength) will hardly deteriorate throughout its entire life cycle.
Tempering treatment: The formed glass umbrella tray is subjected to a "physical tempering" process with suitable cooling speed. This forms a long-term high strength compressive stress layer on its surface, while a tensile stress equilibrium is formed internally. This makes its mechanical strength (compressive and impact resistance) several times higher than ordinary glass.
The physical basis of 'zero value self explosion': This stress structure is the source of its most famous characteristic. Once the insulator loses its insulation performance due to lightning strikes, internal defects, or external damage (i.e. becomes a "zero value" or "low value"), current breakdown or local overheating will disrupt the internal stress balance, causing the entire glass umbrella to instantly shatter and break. This is equivalent to an intuitive 'fault indicator', where operation and maintenance personnel do not need to climb the tower, but can use a telescope to detect fault points from a distance without omission, achieving meticulous inspection results.
2. Mechanical load-bearing components: metal accessories (fittings)
Material and Connection: Usually made of high-strength malleable cast iron or ductile iron, including cap (upper end) and foot (lower end).
Hat socket structure: The commonly used ball and socket connection method is widely recognized. This structure allows the insulator string to rotate flexibly within a certain angle, effectively releasing the mechanical stress (such as wind pressure and dancing) transmitted by the wire, avoiding dangerous bending moment concentration, and protecting the glass components from lateral force damage.
Locking system: equipped with excellent locking pins (such as R-shaped pins, hunchback pins) to prevent the ball head from slipping out of the ball socket and confirm the mechanical integrity of the connection.
3. Key junction: cement adhesive
Function: Used to firmly bond glass umbrella trays with metal caps and feet. It is not ordinary cement, but specially formulated high-grade acid salt cement or sulfoaluminate cement, with a thermal expansion coefficient that matches finely with glass and metal.
Buffer and stress equalization: During the curing process, the cement adhesive layer can evenly transmit and disperse mechanical loads, buffer the small deformation differences between metal and glass caused by temperature changes, and prevent stress concentration from causing glass fracture.
4. External sealing and protective layer
Sealing glue: On the surface of the cement bonding area, a stable waterproof (based on actual reports) sealing glue (such as silicone glue) will be applied. This is the key to confirming long-term excellence, as it can effectively prevent moisture and corrosive gases from entering the joint, prevent internal hardware corrosion and cement "aging", and protect mechanical strength from degradation for decades.
5. Umbrella skirt exterior design (functional structure)
Standard type: The umbrella skirt is smooth, and the groove design balances creepage distance and self-cleaning.
Anti fouling type: using alternating large and small umbrellas or deep edged umbrella structure. This design can significantly increase the creepage distance (i.e. the length of the path through which current leaks along the surface), while creating air turbulence under complex umbrella shapes, preventing arc development, and utilizing rainwater to achieve good self-cleaning effects, greatly improving the anti flashover ability in polluted areas.
