what materials are used for rotary shaft seals | Insights by Polypac

Rotary shaft seals, also known as lip seals or oil seals, are essential components in machinery that involve rotating shafts. They prevent the leakage of lubricants while keeping contaminants such as dust and moisture out, thereby enhancing the performance and lifespan of bearings and other system components.

Common Materials Used in Rotary Shaft Seals

The selection of materials for rotary shaft seals is crucial, as it directly impacts their performance, durability, and suitability for specific applications. The most commonly used materials include:

• Nitrile Rubber (NBR): Ideal for general-purpose applications, NBR offers resistance to lubricating oils, hydraulic oils, and water. It operates effectively within a temperature range of -30°C to 100°C (-22°F to 212°F) and is suitable for shaft surface speeds up to 12 m/s. However, NBR is not resistant to acids and solvents.

• Fluorocarbon Rubber (FKM): Known for its high-temperature and chemical resistance, FKM performs well in temperatures ranging from -20°C to 200°C (-4°F to 392°F). It is more resistant to acids and solvents compared to NBR and can handle shaft surface speeds up to 38 m/s.

• Polyacrylate Rubber (ACM): ACM is suitable for high-temperature applications and offers good resistance to lubricating oils and water. It operates effectively within a temperature range of -20°C to 150°C (-4°F to 302°F).

• Hydrogenated Nitrile Butadiene Rubber (HNBR): HNBR provides enhanced resistance to heat, oil, and wear, making it suitable for demanding applications. It operates effectively within a temperature range of -30°C to 150°C (-22°F to 302°F).

• Ethylene Propylene Diene Monomer (EPDM): EPDM is known for its excellent resistance to heat, ozone, and weathering, and is suitable for sealing water and steam. It operates effectively within a temperature range of -50°C to 150°C (-58°F to 302°F).

Key Considerations for Selecting Rotary Shaft Seals

When choosing a rotary shaft seal, consider the following factors to ensure optimal performance:

• Operating Temperature: Select a material that can withstand the maximum and minimum temperatures of your application.

• Chemical Compatibility: Ensure the seal material is compatible with the fluids it will encounter to prevent degradation.

• Shaft Speed: Choose a material that can handle the shaft's surface speed without excessive wear.

• Pressure Conditions: Consider the operating pressure to select a seal that can maintain integrity under those conditions.

• Environmental Factors: Account for exposure to contaminants such as dust, water, or chemicals that may affect seal performance.

Conclusion

Selecting the appropriate material for rotary shaft seals is vital for ensuring machinery reliability and longevity. By carefully considering factors such as operating temperature, chemical compatibility, shaft speed, pressure conditions, and environmental factors, you can make an informed decision that aligns with your specific application requirements.

About Polypac

Polypac is a leading manufacturer specializing in high-quality rotary shaft seals. With a commitment to innovation and precision, Polypac offers a comprehensive range of seals tailored to meet diverse industrial needs. Their products are known for durability, reliability, and performance, ensuring optimal sealing solutions for various applications.

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