Gas-insulated Bushings

Gas-insulated bushings by PFISTERER are proven technology for single-pole outdoor connections from gas-insulated switchgear (GIS) to air-insulated switchgear and overhead lines. Customers and OEMs around the world value the reliability and economy of our customised and innovative complete solutions. These provide the basis for successful, long-lasting and cost-effective projects.

Quality with full service

The key features of our bushings are their hollow core silicone or ceramic insulators, and the know-how that results from decades of application experience. At PFISTERER, our range of services covers everything from consultation, to development and simulation, to production and testing for each individual bushing in accordance with applicable IEC standards and customer specifications. Testing is carried out exclusively by our in-house laboratories – including the High Voltage Lab in Selb/Germany, which is unique in Europe and has been refurbished with state-of-the-art equipment. Together with our customers, we are also developing novel solutions using alternative, future-oriented insulating media.


Key factors:

Everything from a single source

PFISTERER is a full service partner for plant engineering, from the development and simulation of bushings through to final in-house testing – both mechanical and dielectric.

Defined processes guarantee a smooth project flow from consultation to installation, as well as a high degree of transparency and planning certainty.

Voltage range 72.5 to 500 kV

PFISTERER offers bushings in the full voltage range between 72.5 and 550 kV. Development and production are carried out in line with customer-specific requirements and applicable standards. Overall lengths, shed shapes and creepage distances are determined according to the insulation coordination, required clearances, and environmental conditions (e.g. pollution).

Silicone and ceramic bushings

PFISTERER offers customised solutions for all GIS applications. Depending on the application and environmental conditions, silicone or ceramic bushings are used.

Robust and hydrophobic
Silicone bushings are breakage resistant under shock stresses, while also being lighter in weight than ceramic bushings of the same voltage level. Silicone also has the key property of hydrophobicity. It prevents the formation of a continuous water film – which could establish a conductive path and bridge the insulation – and also means that the insulator is self-cleaning.

Silicone bushings – properties

  • Lightweight solution
  • Able to withstand high shock loads
  • Key property: hydrophobicity
  • Easy to repair
  • High degree of security

Proven and resilient
Porcelain has been established as an insulation material for over one hundred years. Bushings made of high-performance ceramics are still standard in many core markets, e.g. the Middle East. Due to their dimensional rigidity, they exhibit higher mechanical strength. Plus they are highly resistant to surface degradation in the event of partial discharge.

Ceramic bushings – properties

  • Established material
  • Reference in various core markets
  • High mechanical strength
  • Extremely durable
  • Ceramic insulator is not hazardous waste on disposal
Minimal use of SF6

SF6 gas harms the environment. PFISTERER is therefore committed to responsible and economical use of this gas. The compact size and optimised design of our bushings ensure minimal use of SF6 insulating gas. Projects to develop bushings with alternative insulating gases are currently in progress.

Experienced partner for OEMs

PFISTERER supports and invests heavily in the research and innovation of composite materials and advanced ceramics. The group of companies has its own test laboratory at each production site to monitor our products during and after the production process.

Research teams regularly conduct scientific studies, which are presented for example at CIGRE (International Council on Large Electric Systems). Their findings influence IEC norms and standards throughout the industry.

In-house testing laboratories

PFISTERER bushings are type-tested and individually tested in accordance with applicable international standards. Testing is carried out in our own high-voltage laboratories, including the chemical-physical lab in Wunsiedel/Germany, and the High Voltage Lab in Selb/Germany.

The High Voltage Lab in Selb is unique in Europe. It carries out comprehensive test procedures on items we produce as well as for third parties. This includes type examination and testing of insulators, insulator strings and bushings in conformity with current standards.