Why Seals Fail: 13 Key Causes and Proven Prevention Tips

Why Seals Fail: 13 Key Causes and Proven Prevention Tips

Seals play a critical role in maintaining industrial equipment efficiency, reliability, and safety. However, seal failures remain a frequent cause of costly downtime, equipment damage, and increased safety risks—statistics indicate seal issues account for up to 30% of maintenance-related expenses. Understanding why seals fail and how to prevent these failures is essential for operational efficiency and cost control.

This guide explores 13 common causes of seal failure, paired with proven prevention strategies, helping you choose durable rubber seals that keep your machinery running smoothly.

1. Installation and Design Issues

Improper Seal Installation

Issue: Misalignment, uneven tightening, or improper seating cause premature seal leaks, distorting seals or failing to hold adequate pressure.
Prevention Tip: Follow precise torque guidelines and alignment protocols; utilize installation tools specifically designed for seal placement.

Incorrect Seal Selection

Problem: Choosing the wrong seal size or type leads to rapid failure, increased wear, and leakage.
Prevention: Precisely measure shaft and housing dimensions; select double-lip designs for high-demand applications.
Buyer Tip: Verify dimensions with manufacturers prior to ordering.

Poor Shaft or Housing Design

Problem: Misaligned shafts or housings with poor tolerances create uneven stress, dramatically reducing seal lifespan.
Prevention: Adhere to precise machining tolerances and industry-standard shaft/housing specifications to maintain even seal pressure.

2. Material and Environmental Challenges

Improper Material Compatibility

Problem: Seals degrade quickly if material compatibility isn’t matched to environmental conditions (temperature, chemicals, and pressures).
Prevention: Choose materials based on specific environmental demands:

Temperature Extremes

Problem: High heat hardens seals; low temperatures cause brittleness, both leading to leaks.
Prevention: Select specialized materials, like FKM for high temperatures or silicone-based seals for cold environments.

Chemical Degradation

Problem: Aggressive chemicals accelerate seal deterioration.
Prevention: Opt for chemically resistant materials, such as FKM or PTFE, and regularly evaluate chemical exposure in your operations.

Ozone and UV Exposure

Problem: Exposure to ozone and UV accelerates seal aging, reducing lifespan and causing cracks.
Prevention: Use UV-resistant materials like EPDM for outdoor applications and store spare seals properly.

3. Operational and Pressure Issues

Excessive Pressure

Problem: Seals subjected to pressures beyond their limits deform, extrude, or fail outright.
Prevention: Always confirm seals’ rated pressure capacities match or exceed your system’s operational maximum (e.g., seals rated up to 5000 psi).

Poor Surface Finish

Problem: Rough shaft or housing surfaces increase friction, causing premature seal wear.
Prevention: Maintain a smooth surface finish (Ra 10-20 microinches) on mating components to reduce seal wear and friction.

Incorrect Lubrication

Problem: Using the wrong lubricant type or inadequate lubrication increases friction and accelerates seal failure.
Prevention: Always apply lubricants compatible with your seal material—silicone grease for silicone-based seals, mineral-based oils for NBR.

Expert Opinion (John Wang, Equipment Maintenance Engineer):

“Regularly checking the lubrication status of seals is key to preventing failures. Proper lubrication not only reduces friction but also extends seal life. Many industrial failures stem from improper lubrication of seals, which is something that factory owners and car owners need to pay special attention to.”

4. Aging, Wear, and Dynamic Conditions

Natural Aging and Wear

Problem: Seals naturally degrade over time due to repeated operational cycles, environmental exposure, and oxidation.
Prevention: Schedule regular inspections and replace seals proactively every 2–5 years, selecting materials engineered for longevity.

Dynamic Stress and Movement

Problem: Continuous mechanical stress, vibration, or dynamic movements wear seals quickly.
Prevention: Use seals specifically designed for dynamic applications (e.g., rotary seals, spring-loaded seals) to handle mechanical stress better.

Contamination and Abrasive Particles

Problem: Contaminants such as dirt, metal shavings, and particulate matter cause abrasive damage to seals.
Prevention: Implement filtration systems, routine cleaning protocols, and protective shields to reduce contamination.

5. Case Study: High Temperature and Pressure Seal Failure in the Chemical Industry

In the chemical industry, seals are often exposed to extreme temperatures and aggressive chemicals. A notable case involved a chemical plant where NBR seals failed in a high-temperature environment (above 300°F), leading to significant downtime. The replacement of these seals with FKM seals, which have a much higher tolerance for heat, resulted in a marked improvement in equipment reliability. This case underscores the importance of selecting the correct material for specific environmental conditions.

6. Detailed Seal Replacement Steps

1. Close the Equipment and Depressurize: Ensure the system is powered off and all pressure is released.
2. Remove the Old Seal: Use specialized tools to carefully remove the old seal without damaging surrounding components.
3. Clean the Installation Area: Thoroughly clean the shaft and housing surfaces to remove any debris.
4. Check Surface Finish: Ensure the surfaces are smooth and free of defects.
5. Install the New Seal: Insert the new seal in the correct orientation, ensuring a proper fit.
6. Inspect for Leaks: After installation, verify the seal is functioning correctly with no leaks or misalignments.

Conclusion

Seal failures are often caused by installation errors, material incompatibility, extreme operational conditions, and natural wear. By addressing these 13 root causes, businesses can significantly reduce downtime, save maintenance costs, and extend equipment lifespan.

Choosing durable rubber seals and applying proactive prevention strategies ensures machinery reliability and operational efficiency. To assist in choosing the right seals and to find solutions tailored to your needs, DRO Rubber Seals offers expert guidance and customized sealing solutions for all industries.

Ready to enhance your equipment’s reliability?
Contact DRO Rubber Seals today:
Website: drorubber.com
Email: [email protected]
Phone: +86 1384044874
Request your free sample today!