Seals and Plain Bearings for Power Plants: How High-Performance Materials Enhance Operational Safety

Gas and steam power plants, coal-fired power plants, and nuclear power plants place high demands on their components. For manufacturers of pumps, turbines, compressors, and sealing systems, the challenge goes beyond ensuring that individual parts function properly. Service life, plant availability, and operational safety are equally important. 

This is especially true in safety-critical applications, where premature wear or component failure can lead to unplanned downtime. Beyond maintenance and repair costs, failures can also delay commissioning. 

Requirements continue to evolve. New power generation technologies, including Small Modular Reactors (SMRs), and specific requirements for nuclear safety and Counterfeit, Fraudulent, and Suspect Items (CFSI) place additional demands on materials and quality assurance. 

For manufacturers, achieving a reliable solution often starts with selecting the right material. 

For mechanical seals and bearings, material behavior under friction and mechanical loads is particularly important. These characteristics are known as tribological properties. 

Schunk develops and manufactures materials for sealing surfaces as well as radial and axial bearings used in power plants. Its portfolio includes carbon and graphite materials, silicon carbide (SiC), and graphite-SiC composite materials. 

Three properties are particularly important when selecting materials: 

• Wear resistance: Seal and bearing components need to maintain reliable performance over extended operating periods. 

• Corrosion resistance: Materials must be compatible with the media they come into contact with. 

• Chemical resistance: Depending on the application, components may be exposed to different chemical environments. 

The most suitable material depends on the specific operating conditions. No single material is the right choice for every sealing or bearing application. 

Two examples from Schunk’s product portfolio illustrate how these materials are used in power plant applications.

Schunk offers SiC30 seal rings for demanding sealing applications. They are part of the company’s portfolio of materials and components for sealing surfaces in power generation equipment. 

When designing a mechanical seal, the sealing surface materials must be selected according to the operating conditions. Schunk supports manufacturers with application-specific materials consulting to help identify suitable solutions. 

Material selection is equally important for bearings. Schunk offers carbon slide bearings for applications with demanding tribological requirements. 

The company supplies materials for radial and axial bearings, including those used in power plant pumps. 

Schunk also manufactures large-scale components with outer diameters of up to 700 mm, providing options for applications that require larger component dimensions. 

Many technical decisions are made during the initial design of new pumps, power generation units, or sealing systems. Choosing the right seal and bearing materials is one of them. 

Schunk recommends involving materials specialists early in the development process. This allows materials and components to be tailored to the application's specific requirements from the outset. 

Early collaboration is particularly valuable in safety-critical applications, where technical performance must be considered alongside strict quality requirements. 

Schunk supports OEMs with decades of industry experience, application consulting, and customized quality agreements. Application-specific materials and component solutions are also available. 

For power plant operators, long-term equipment reliability is a priority. Unplanned maintenance and plant shutdowns need to be kept to a minimum. 

Suitable sealing and bearing materials can help extend component service life and improve plant availability. 

One important metric is Mean Time Between Service (MTBS), which describes the average time between service interventions. Schunk materials can help increase this interval. 

Safety-critical areas of power plants also have specific quality assurance requirements. Schunk is prepared to meet requirements related to CFSI compliance and nuclear safety.

Whether it's a mechanical seal, a slide bearing, or a custom-engineered component, power plant applications have different technical requirements. Materials and components must be selected to match the conditions in which they will operate. 

Schunk supports manufacturers of seals, pumps, turbines, and compressors with carbon and graphite materials, silicon carbide, and application-specific consulting. From the early design phase through material selection, the focus remains on reliable component performance.

Looking for suitable materials for mechanical seals or bearings in power plant applications? Talk to our experts about your technical requirements. 

Here you can find relevant brochures, technical documents, and further information on carbon, graphite, and silicon carbide materials for seals and plain bearings in power plant applications.

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