Which Seal Materials are Best for the Renewable Energy Industry?

solar wind energyAs the market for the renewable energy industry grows, so does an increased need for rubber seal material to protect components and parts from failure during operation. Renewable energy, also referred to as clean energy, derives from natural sources or processes that can be constantly or readily replenished. The most common or widely known forms of renewable energy are solar or wind, but other forms are derived from hydroelectric power, biomass energy, geothermal energy, and tidal and wave energy from the ocean.

Applications in the renewable energy industry utilize rubber seal material to protect components from a wide range of contaminants—dirt, dust, debris, humidity and moisture, for example. The wear and tear on components and parts are unique to the industry. Whether it’s prolonged exposure to heat and sunlight from solar applications or a pounding gale from the wind or high temperature from geothermal heat pumps, sensitive electronic components need to be sealed effectively for optimal performance.

Rubber seals are necessary to join mechanical mechanisms together and prevent leakage of fluids from applications. The seals are actually made with synthetic rubbers, i.e., elastomeric compounds formulated to meet certain or specific conditions required of the workpiece. Such applications in the renewable energy sector rely on rubber parts and components like o-rings, gaskets, rubber extrusions, moldings, pneumatic seals, slew ring seals, hydraulic seals, coupling rubbers, and other type seals.

Because such environments can be subjected to harsh conditions ranging from wide temperature swings to extreme weather, rubber seals selected must have the mechanical properties to meet diverse conditions. Choosing the right material ensures the seal functions as intended and to its fullest potential in the harshest environments.

Here are four of the best seal materials used in the renewable energy industry:


Known to offer the best fluid resistance of any commercial rubber, Viton retains good mechanical properties in temperature applications between 5°F and 250°F. The material is durable, remains substantially elastic, and is resistant to oils and chemicals at elevated temperatures. It could be used in most renewable energy applications.


Also referred to as Nitrile or Buna-N, Buna displays excellent resistance to all petroleum-based oils and fuels. It also provides good resistance to water, various alcohols, silicone greases, and hydraulic fluids. It offers good tear resistance, non-polar solvent resistance and has an effective temperature range of -40°F and 250°F. It’s also relatively less expensive than other similar materials. It would be effective in hydroelectric, tidal, and biomass renewable energy sectors. On the con side, its flexibility is limited and has poor ozone, sunlight, and weather resistance.

Silicone rubber

As one of the more highly-resistant elastomers, silicone’s main mechanical property is its thermal stability. It operates in the harshest environmental conditions and functions in a temperature range from minus 100°F to plus 500°F, providing excellent electrical insulation and seals for high-temperature fluids. In addition to its high-temperature resistance, it’s exceptionally durable and flexible. Silicone rubber resists normal aging, too, can last for decades, and retains its shape in the most adverse environmental conditions.


Though it has a comparatively low service temperature of 25°F, Aflas offers exceptional heat and fire resistance with a continuous service temperature capability of up to +400°F. It is resistant to petroleum products, steam, and phosphate-esters, i.e., primarily in fire-resistant base stocks fluids for such applications as hydraulic systems, turbines, and compressors. With superior electrical insulation properties, Aflas has very good mechanical strength, which allows for thinner wires for larger electrical currents. Its high-temperature compression set resistance is less than standard fluorocarbons, but it does offer improved chemical resistance. It resists motor oils of all types, extreme pressure (EP) gear lubricants, and transmission fluids, brake fluids, and silicone oil. It’s also an excellent choice for high-temperature applications (+340°F) such as heat transfer media, amines, acids, and bases, as well as hot water and steam.

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