How to extend the life of your seals: A comprehensive guide

Seals are inconspicuous yet essential components in countless applications—from household appliances to automobiles to complex industrial systems. They prevent leaks and protect against environmental influences, ensuring the smooth functioning and longevity of systems. But even the best seals have a limited lifespan. Together, we'll explore how long different types of seals last, why their lifespans vary, and, most importantly, what you can do to significantly extend them.

Which seals have which lifespan?

The service life of a seal depends on a variety of factors, primarily the material, operating conditions, and manufacturing quality. Here is an overview of the typical service lives of various sealing materials:

• Elastomer seals (rubber and TPE): This category includes a wide range of materials such as natural rubber (NR), styrene butadiene rubber (SBR), ethylene propylene diene rubber (EPDM), nitrile rubber (NBR), silicone (VMQ) and thermoplastic elastomers (TPE).

  • Natural rubber (NR): Offers good abrasion resistance and elasticity, but is susceptible to ozone and weathering. Its service life can be 5 to 10 years under ideal conditions, but significantly shorter under stress.

  • Styrene-butadiene rubber (SBR): Similar to natural rubber, it has good abrasion resistance but also limited resistance to environmental influences. The service life is typically 5 to 8 years .

  • Ethylene propylene diene rubber ( EPDM ): Excellent resistance to ozone, UV radiation, weathering, and many chemicals. A service life of 10 to 20 years or more is possible in suitable applications.

  • Nitrile rubber (NBR): Very good resistance to oils, greases, and fuels. The service life is typically between 7 and 15 years , depending on the specific operating conditions and the type of media.

  • Silicone (VMQ): Excellent resistance to high and low temperatures, as well as UV radiation and ozone. Silicone seals can achieve a service life of 10 to 25 years or even longer under moderate loads.

  • Thermoplastic elastomers (TPEs): Offer a combination of the properties of rubber and plastics. Their service life varies greatly depending on the specific TPE type and application, but can range from 5 to 15 years .

    
    

• Plastic seals: These include materials such as polytetrafluoroethylene (PTFE), polyamide (PA) and polyoxymethylene (POM).

  • Polytetrafluoroethylene (PTFE): Known for its excellent chemical resistance and wide temperature range, PTFE seals can have an extremely long service life of 20 years or more under moderate conditions.

  • Polyamide (PA): Offers good strength and abrasion resistance, but is sensitive to moisture and some chemicals. The service life is typically between 5 and 10 years .

  • Polyoxymethylene (POM): Characterized by high stiffness, strength, and good chemical resistance. The service life can be 8 to 15 years in suitable applications.

    
    

• Metal seals: These are used in high-pressure and high-temperature applications. Their service life is often very long and depends primarily on the corrosion resistance of the metal and the mechanical stresses. With corrosion-resistant alloys and proper installation, they can Last for decades.

  
  

Important note: These specifications are guidelines and may vary considerably depending on the specific application, seal quality and actual operating conditions.

Why does the lifespan vary so much?

The differences in the service life of different seals can be attributed to a number of factors:

• Material properties: Every material has specific strengths and weaknesses in terms of resistance to temperature, chemicals, UV radiation, ozone, abrasion, and mechanical stress. Elastomers, for example, can harden or become brittle over time, while plastics can swell or decompose under certain chemical influences. Metals can corrode.

• Operating conditions: The environmental conditions to which a seal is exposed play a crucial role. High or low temperatures, aggressive media, high pressure, constant movement, or vibration can significantly accelerate the wear process.

• Mechanical stress: Static seals are generally less susceptible to wear than dynamic seals, which are subject to constant movement or pressure changes. The type and intensity of mechanical stress significantly influence their service life.

• Manufacturing quality: A high-quality seal that is precisely manufactured and meets specifications will generally last longer than a substandard product. Factors such as material purity, dimensional accuracy, and surface finish are crucial.

• Installation: Improper installation, such as overstressing, incorrect alignment, or using unsuitable tools, can damage the seal and shorten its lifespan.

• Maintenance: Regular maintenance and inspection can help identify problems early and extend the life of the seals.

What can I do to extend the lifespan?

There are a number of measures you can take to significantly extend the lifespan of your seals:

1. Choosing the right material: Carefully select the sealing material based on the specific requirements of your application. Consider the following:

   • Temperature range: Ensure that the material can withstand the minimum and maximum operating temperatures.

   • Chemical resistance: Choose a material that is resistant to the media it comes into contact with (e.g. oils, acids, alkalis, gases).

   • Pressure load: The material must be able to withstand the maximum operating pressure.

   • Dynamic or static application: Abrasion-resistant and flexible materials are required for moving parts.

   • Environmental influences: For outdoor applications, resistance to UV radiation, ozone and weathering is important.

2. Careful installation: Pay extreme precision when installing new seals:

   • Clean the sealing surfaces thoroughly: Remove dirt, deposits and old sealing residues.

   • Use the right tool: Avoid damaging the seal during installation.

   • Observe the tightening torques: Tighten screws or other fasteners according to the manufacturer's specifications to ensure even pressure distribution.

   • Use lubricants if necessary: Special seal lubricants can facilitate assembly and protect the seal from damage. Make sure the lubricant is compatible with the seal material and the media.

3. Regular maintenance and inspection: Carry out inspections of the seals at regular intervals:

   • Visual inspection: Look for cracks, swelling, deformation, discoloration, or other signs of wear.

   • Functional test: Check whether the seal still seals reliably.

   • Cleaning: Regularly remove dirt and deposits from the seals and surrounding areas.

4. Optimize operating conditions: If possible, optimize the conditions under which the seals operate:

   • Reduce extreme temperatures: Avoid excessive heat or cold, which can stress the material.

   • Avoid unnecessary pressure peaks: A consistent operating pressure protects the seals.

   • Minimize vibration and movement: In dynamic applications, measures to reduce vibration and excessive movement can extend service life.

   • Protect against harmful environmental influences: For outdoor applications, a cover or protective coating can protect the seals from UV radiation and weather influences.

5. Correct storage of spare seals: When storing spare seals, please note the following points:

   • Cool and dry environment: Avoid extreme temperatures and high humidity.

   • Protection from light and ozone: Store the seals in dark containers or rooms and away from ozone sources (e.g. electric motors).

   • Avoid mechanical stress: Store the seals so that they are not crushed, bent or otherwise deformed.

   • Observe storage times: Some elastomers have a limited shelf life, even when not in use. Check recommended storage times.

   
   
   
   

How do I know when the end of its service life has been reached and what should I do in time?

There are several signs that a seal has reached the end of its service life and should be replaced:

• Visible damage: Cracks, breaks, abrasion, swelling, deformation or discoloration are clear indications of material wear.

• Leaks: The most obvious sign of a defective seal is the leakage of liquids or gases.

• Loss of elasticity: Elastomer seals can harden or become brittle over time and lose their ability to conform to surfaces.

• Noises: Hissing or whistling noises may indicate a leaky seal.

• Malfunctions: In systems where seals play a critical role (e.g. in hydraulic or pneumatic systems), malfunctions can be due to defective seals.

  
  

What to do when the end of its life is reached?

As soon as you notice signs of seal damage or the end of its service life, you should act immediately :

1. Identify the defective seal: Locate the exact location of the leak or damage.

2. Obtain a suitable replacement seal: Ensure the new seal has the correct dimensions and is made of the appropriate material for the application. Consider the material selection criteria listed above.

3. Replace the seal: Perform the replacement carefully according to the device or system manufacturer's instructions. Ensure a clean installation.

4. Check the function: After replacing the seal, check whether the system is working properly again and no leaks occur.

5. Analyze the cause of the failure: Try to determine the reasons for the premature wear of the old seal to prevent future problems. Were the operating conditions too extreme? Was the material unsuitable? Were there installation errors?

   
   

A timely response to signs of seal wear can prevent expensive consequential damage and downtime.

With over 30 years of experience , REXIO® GmbH & Co. KG is at your side worldwide for high-quality and innovative sealing solutions made of silicone, TPE, and other elastomers, as well as edge protection profiles and customized consulting. Discover our diverse products and request a free consultation today.

Conclusion

Seal life is a critical factor for the reliability and cost-effectiveness of many applications. Through careful selection of the right material, professional installation, regular maintenance, and optimization of operating conditions, you can significantly extend the service life of your seals, thus reducing costs and downtime. Look for signs of wear and take timely action to prevent major damage.

Contact us now