Choosing the Right Mechanical Seal for High-Temperature Applications

High-temperature applications are among the most challenging for mechanical seals. In power generation, petrochemicals, and food processing, the equipment is usually exposed to high temperatures that can break down the seal material and its functionality. The choice of mechanical seal material in high-temperature applications will therefore be critical to achieving the desired performance and avoiding premature failure.

Important Considerations for High-Temperature Mechanical Seals

1. Material Temperature Range: Seals of various materials have different ranges of temperature tolerance. Carbon and graphite seals are usually up to 350°C while others like tungsten carbide and ceramics can sustain temperatures above 800°C.

2. Thermal Expansion: As temperatures rise, materials expand. A mechanical seal must be able to accommodate this thermal expansion without compromising its sealing integrity. Seals made from materials with similar thermal expansion properties to the equipment are ideal for high-temperature applications.

3. Wear Resistance: High temperatures increase wear and friction. High-performance materials like tungsten carbide, ceramics, and specially designed composites provide the best resistance to wear and ensure seal integrity in extreme thermal stresses.

4. Chemical Resistance: In high-temperature applications, seals must also resist the corrosive effects of fluids or gases. Elastomers such as Viton or PTFE provide excellent chemical resistance, while metals like stainless steel provide robust protection in both high temperatures and corrosive environments.

5. Seal Design: For high-temperature applications, it is advisable to use a seal design that can resist thermal cycling. Double seals with a barrier fluid system or spring-energized seals may offer extra protection from temperature variations.

Recommended Mechanical Seal Materials for High-Temperature Applications

• Tungsten Carbide: This provides excellent high-temperature and wear resistance and is appropriate for power generation, petrochemical, and high-temperature industrial processes.

• Ceramic: This material provides excellent resistance to heat, wear, and chemical degradation, suitable for extreme temperature and pressure conditions.

• Graphite and Carbon: These materials are usually applied in high-temperature applications with dry running capabilities, such as in vacuum pumps or high-temperature reactors.

The mechanical seal to be used in high temperature applications is a careful evaluation of the operating conditions, fluid characteristics, and desired seal life. If the right choice is made, then you can rely on operation even in the most demanding environments.