Silicone Rubber Insulator


Applications of silicone rubber insulators

The silicone rubber insulators usually consist of silicone rubber housing, ECR fiberglass rod and metal end fittings. When comparing with other kinds of insulators it has many advantages.

Silicone rubber insulators benefit from the manufacturing possibilities of the FRP (fibre reinforced plastic) rod, and in particular from the fact that FRP rods can be produced practically endlessly in one piece in lengths of up to 20 m which is not possible with conventional insulator materials such as porcelain and glass. Silicone rubber insulators are currently produced in lengths of 10–100 cm for low-voltage and medium-voltage network systems, and in lengths up to 10 m andmore for today’s UHV network systems.

Silicone rubber insulators are primarily used in suspension strings in straight-line supports and as tension strings in anchor towers and dead-end towers. They are also used in the jumpers or portals of outdoor substations. In some cases, composite long rods are used in the guys of wooden poles, and more rarely in the guys of steel towers.

Since, in contrast to porcelain and glass insulators, composite long rod insulators can be formed in one piece up to the highest of voltages, they only weigh a fraction of conventional insulators (at 400 kV they weigh approximately 10 % of a comparable porcelain long rod).

Composite insulators, and in particular their advantages under extreme pollution, have been ‘‘discovered’’ in the meantime by railway operators and are thus also being used increasingly in railway catenary systems.

tension composite insulator string

Biref history of GW's silicone rubber insulator

The silicone rubber insulators usually consist of silicone rubber housing, ECR fiberglass rod and metal end fittings. When comparing with other kinds of insulators it has many advantages. And they are become more and more popular for the power transmission lines during these years.

Xiangyang Guowang Composite Insulators Co., Ltd. (GW) is located in Xiangyang, China, and has been serving the field of composite suspension insulator for more than forty (20) years throughout world and other countries. In the 1980s GW was the first company who use silicone rubber composite materials for insulators’ housing and sheds. The extensive experience in composite suspension insulator has made GW become the market leader in China and many other countries. 

As one of the biggest silicone rubber insulator manufacturers, we have the following advantages:

  • Twenty (20) years of experience in design and production of composite long rod insulator technology.
  • High quality HTV silicone rubber made, optimized, applied for the purpose of application.
  • Productcomposite long rod insulators with voltage from 10 kV to 1000 kV, which applicable for both distribution and transmission system.
  • Injection moulding process and modular process.

Silicone rubber insulator properties

Superior electrical performance and high mechanical strength. The tensile and flexural strength of the ECR fiberglass rod carried inside is 2 times higher than that of ordinary steel, and 8 to 10 times that of high-strength ceramic materials, which effectively improves the reliability of safe operation.

Silicone rubber insulators have good anti-pollution performance, good anti-pollution performance, strong anti-pollution flashover performance etc. And its wet withstand voltage and pollution withstand voltage are 2~2.5 times of the same creepage distance of porcelain insulators. Also, it does not need to be cleaned, and it can operate safely in heavily polluted places.

Silicone rubber insulator has a smaller size and lighter weight, which is only 1/6~1/9 of the same voltage level porcelain insulator, and they are easy to transport and install.

The silicone rubber sheds and sheath has good water-repellent performance, and its overall structure ensures that the inner insulation is not damp, and there is no need for preventive insulation monitoring tests or cleaning, which reduces the workload of daily maintenance.

The silicone rubber insulator has good sealing performance and strong electrical corrosion resistance. The shed material has a TMA4.5 (or 2A 6) level of resistance to electrical leakage and tracking. It has good aging resistance, corrosion resistance and low temperature resistance. It can be used in -40~-50 °C area.

The silicone rubber insulator has strong impact resistance and shock resistance, good anti-brittleness and creep resistance, not easy to break, high bending resistance, high torsional strength, can withstand internal pressure, strong explosion-proof force, can be combined with porcelain, glass Insulator interchange.

Production Capacity 

Xiangyang Guowang Composite Insulators Co., Ltd was established in 1997. The company covers an area of more than 123,000 square meters, which is one of the biggest silicone rubber insulator manufacturers in China . The enterprise has a production capacity of 1 million 220 kVcomposite suspension insulators per year. Also the production capacity maybe adjusted according to customers' requiments. We have a lot of expreience for manufacturing insulators with voltages of 220 kV, 330 kV, 400 kV, 500 kV, 600kV, 700kV etc.

Silicone rubber insulator price

The price of Silicone rubber insulators are affected by many reasons, like the ordered quantities, raw materials costs, mould fees, delivery prices etc. And the delivery prices have been 6-10 times of what 2 years ago, that give much pressure for Chinese silicone rubber insulators exporter.

Technical Parameters

Typical System Voltage Dry arc distance, mm 50 Hz Flashover (kV) Lightning Flashover (kV) 50 Hz Withstand (kV) Lightning Withstand (kV)
dry wet Pos. Neg. wet dry Pos. Pos.
100-138KV         970 351 333 558 581 325 340 540 560
1090 351 333 558 581 325 340 540 560
1210 450 428 720 725 390 410 650 690
1270 486 459 779 779 405 430 700 720
1390 527 491 783 788 435 470 750 785
1540 563 522 905 900 475 510 850 870
  220KV-230KV 1690 599 554 968 963 510 550 920 950
1815 630 585 1062 1053 535 580 980 1015
1965 702 648 1152 1143 565 610 1060 1095
2115 738 675 1211 1197 600 660 1140 1175
2265 774 716 1278 1269 630 680 1230 1260
2385 806 738 1346 1323 655 720 1280 1325
300KV-345KV 2475 864 788 1404 1386 670 740 1300 1370
2625 891 801 1503 1476 700 790 1400 1450
2685 896 806 1503 1481 710 800 1430 1485
  400KV 2775 914 828 1557 1526 725 810 1480 1535
2835 936 851 1611 1575 735 820 1500 1565
3045 963 878 1724 1688 770 850 1620 1680
500KV 3315 1044 954 1841 1796 815 900 1780 1825
  3555 1085 995 1944 1899 855 940 1900 1955
3975 1112 1022 2007 1958 915 1000 2130 2180
4275 1508 1130 2259 2264 960 1330 2300 2345
4635 1607 1175 2439 2466 1005 1430 2500 2540