In the world of industrial sealing, high temperature applications present unique challenges. Selecting the right material for seals, gaskets, and o-rings is crucial to ensure the longevity and effectiveness of machinery and equipment. This guide delves into the top materials used in high temperature sealing, focusing on silicone, FKM, FFKM, and HNBR, and provides insights into their applications, benefits, and limitations.

Understanding High Temperature Sealing

High temperature sealing involves materials that can withstand extreme temperatures while maintaining their integrity. These materials are essential in industries such as automotive, chemical processing, and oil and gas, where seals are often exposed to harsh environments, including high heat, aggressive chemicals, and fluctuating pressures.

Key Materials for High Temperature Sealing

Silicone

Silicone rubber is one of the most versatile sealing materials, known for its excellent heat resistance, flexibility, and durability. It can withstand temperatures ranging from -60°C to +230°C (-76°F to +446°F), making it suitable for a wide range of applications.

• Benefits:
  • Exceptional temperature range.
  • Good flexibility at low temperatures.
  • Resistance to ozone, UV light, and weathering.
  • Non-toxic and suitable for food-grade applications.
• Limitations:
  • Limited resistance to oils and fuels.
  • Poor tensile strength compared to other materials.
• Applications:
  • Automotive engine components.
  • Food processing equipment.
  • Medical devices.

FKM (Fluoroelastomer)

FKM, commonly known by the brand name Viton, is a high-performance fluoroelastomer renowned for its superior resistance to high temperatures, chemicals, and oils. It operates efficiently in temperatures ranging from -20°C to +250°C (-4°F to +482°F).

• Benefits:
  • Excellent chemical resistance, particularly to fuels and oils.
  • High thermal stability.
  • Good compression set resistance.
• Limitations:
  • Limited low-temperature flexibility.
  • Higher cost compared to standard elastomers.
• Applications:
  • Chemical processing seals.
  • Automotive fuel handling systems.

FFKM (Perfluoroelastomer)

FFKM, also known as perfluoroelastomer, offers the highest level of chemical resistance among elastomers, coupled with the ability to withstand extreme temperatures, typically from -10°C to +327°C (14°F to +620°F).

• Benefits:
  • Unmatched chemical resistance.
  • Exceptional thermal stability.
  • Low outgassing, making it suitable for semiconductor applications.
• Limitations:
  • Very high cost.
  • Limited availability.
• Applications:
  • Semiconductor manufacturing.
  • Chemical processing.
  • Oil and gas exploration.

HNBR (Hydrogenated Nitrile Butadiene Rubber)

HNBR is an upgraded version of nitrile rubber, known for its improved temperature range and enhanced resistance to oil, chemicals, and wear. It operates efficiently between -40°C to +150°C (-40°F to +302°F).

• Benefits:
  • High resistance to heat, ozone, and aging.
  • Good tensile strength and abrasion resistance.
  • Resistant to fuels, oils, and chemicals.
• Limitations:
  • Limited resistance to aromatic hydrocarbons and polar solvents.
  • Less flexible at very low temperatures.
• Applications:
  • Automotive transmission systems.
  • Oil and gas seals.
  • Industrial machinery.

Selecting the Right Material

Choosing the appropriate material for high temperature sealing depends on several factors:

1. Temperature Range: Consider the operating temperature range of the application and select a material that can maintain its integrity within that range.
2. Chemical Compatibility: Evaluate the chemicals the seal will be exposed to, ensuring the material can resist degradation.
3. Mechanical Requirements: Assess the mechanical demands, such as flexibility, tensile strength, and compression set, to ensure the material can perform under the required conditions.
4. Cost Considerations: Balance the material's performance benefits with its cost, especially for applications requiring large quantities or where cost constraints are significant.

Conclusion

High temperature sealing is a critical aspect of many industrial applications, and selecting the right material is key to ensuring reliability and performance. Silicone, FKM, FFKM, and HNBR each offer unique properties that make them suitable for different high temperature environments. By understanding the benefits and limitations of each material, you can make informed decisions that align with your specific sealing needs.

Explore our product range to find the perfect high temperature sealing solution for your application!