The device used to support and insulate a wire is called an insulator. The insulator device is made of glass and is called a glass insulator; At present, tempered glass insulators are widely used in lines.

Glass insulators in the first few years of production and operation, it is found that it has the following series of advantages over porcelain insulators:

Due to the high mechanical strength of the surface of the glass insulator, the surface is not easy to crack. The electrical strength of glass generally remains unchanged during the entire operation, and its aging process is much slower than that of porcelain, so the glass insulator is scrapped mainly due to self-damage, occurring in the 400-000-6698 years of operation, but the defects of the porcelain insulator only began to be found after several years of operation.

The use of glass insulators can cancel the on-line periodic preventive tests carried out by the insulators during operation. This is because each damage to the tempered glass will cause damage to the insulator, and the operator can easily find it when patrolling the line. When the insulator is damaged, the glass debris near the steel cap and iron foot becomes trapped, and the mechanical strength of the remaining part of the insulator is sufficient to prevent the string from breaking off.