Media

 

Why Do Mechanical Seals Leak? How to Troubleshoot Common Sealing Failures

 

Introduction

Mechanical seals play a critical role in preventing leakage in industrial machinery, ensuring the efficiency and reliability of equipment such as pumps, compressors, and mixers. However, even high-quality mechanical seals can fail over time, leading to costly downtime, equipment damage, and fluid loss.

Understanding the common causes of mechanical seal failure and knowing how to troubleshoot them can extend the lifespan of your seals, reduce maintenance costs, and improve overall system performance.

In this guide, we’ll explore why mechanical seals leak, the most frequent failure modes, and how to effectively troubleshoot common sealing failures.

 

Common Causes of Mechanical Seal Leakage

1. Improper Installation

One of the leading causes of mechanical seal leakage is incorrect installation. A mechanical seal consists of multiple components, including a rotating face, a stationary face, and a spring mechanism. If these parts are misaligned or installed with incorrect tension, the seal may fail prematurely.

Solution:
✔ Follow the manufacturer’s installation guidelines carefully.
✔ Ensure proper shaft alignment and use the correct torque when securing the seal.
✔ Check for any burrs or imperfections on the shaft before installation.

 

2. Excessive Shaft Vibration

Excessive vibration can disrupt the sealing surfaces, causing premature wear and leading to leakage. This is especially common in applications where the shaft operates at high speeds or under uneven loads.

Solution:
✔ Inspect for imbalances in rotating equipment.
✔ Use dampening systems to reduce vibration.
✔ Select high-performance seals like Parjet’s ParSeries^® Mechanical Seals, which are designed for demanding industrial environments.

 

3. Thermal Expansion and High Temperatures

Seals operate under various temperature conditions, and extreme heat can cause thermal expansion, leading to material degradation, distortion, or even cracking.

Solution:
✔ Choose temperature-resistant materials such as PTFE, silicon carbide, or Hastelloy^®.
✔ Use cooling systems or double-seal configurations (e.g., ParMix^® or ParDual^® seals).
✔ Monitor operating temperatures regularly to prevent overheating.

 

4. Chemical Incompatibility

Not all mechanical seal materials are compatible with every fluid. Exposure to aggressive chemicals, corrosive fluids, or extreme pH levels can weaken seal materials, causing leaks.

Solution:
✔ Select mechanical seals with chemical-resistant materials like PTFE-reinforced ParLip^® seals.
✔ Cross-check fluid compatibility charts to ensure material suitability.
✔ Regularly inspect seals for signs of chemical degradation.

 

5. Dry Running or Inadequate Lubrication

Mechanical seals require proper lubrication to function efficiently. If the seal faces run dry, friction and heat increase, leading to rapid wear and surface damage.

Solution:
✔ Ensure proper fluid levels in the system.
✔ Use mechanical seals with self-lubricating materials, like ParFloat^® PTFE-reinforced seals.
✔ Check for blockages in lubrication lines that could restrict fluid flow.

 

6. Excessive Pressure and System Overload

High-pressure environments require mechanical seals that can withstand intense operating conditions. If a seal isn’t rated for high-pressure applications, it can distort, crack, or fail completely.

Solution:
✔ Use balanced mechanical seals such as ParDual^®, which can handle up to 25 bar of pressure.
✔ Install pressure relief valves to prevent pressure spikes.
✔ Monitor system pressure regularly to detect fluctuations.

 

How to Troubleshoot Mechanical Seal Failures

When a mechanical seal starts leaking, follow these troubleshooting steps:

1. Identify the Leakage Source:

• •  Is the leak coming from the seal face, gland, or shaft?
• •  Check for visible cracks, wear marks, or surface imperfections.

2.  Check Installation and Alignment:

• •  Ensure that the shaft is properly aligned.
• •  Confirm that the seal was installed correctly without over-tightening.

3.  Inspect Seal Faces for Wear and Contamination:

• •  Look for signs of friction damage, debris buildup, or uneven wear patterns.
• •  Clean or replace damaged seal components as needed.

4. Evaluate Operating Conditions:

• •  Measure temperature, pressure, and shaft speed to ensure they fall within the seal’s specifications.
• •  Upgrade to higher-performance seals if necessary.

5. Choose the Right Seal Material for the Application:

• •  Chemical compatibility: Use PTFE-reinforced seals for aggressive fluids.
• •  High-speed applications: Choose silicon carbide or carbon-based seals.
• •  Abrasive environments: Opt for ParMix^® or ParLip^® with durable wear-resistant materials.

 

Preventative Maintenance Tips for Long-Lasting Mechanical Seals

•  Regular Inspections: Conduct routine maintenance checks to detect early signs of wear.
•  Monitor System Conditions: Keep track of temperature, pressure, and lubrication levels.
•  Use High-Quality Seals: Invest in premium mechanical seals like ParSeries^®, designed for superior durability and performance.
•  Proper Installation and Alignment: Ensure correct installation techniques to avoid premature failures.

 

Parjet’s ParSeries^® Mechanical Seals: Engineered for Reliability

Mechanical seal leakage can cause serious operational disruptions, but understanding the common failure causes and implementing effective troubleshooting techniques can significantly extend seal life and improve system performance.

For industries that demand high-performance mechanical seals, Parjet’s ParSeries® Mechanical Seals provide exceptional durability, leakage prevention, and long-term reliability. Our product line includes:

✔ ParMix^® – Double-Acting Liquid Lubricated Mechanical Seal (High-pressure & high-temperature applications)
✔ ParAce^® – Single Cartridge Seal (Pumps & compressors)
✔ ParDual^® – Dual Cartridge Seal (High-performance sealing)
✔ ParLip^® – PTFE Reinforced Lip Seal (Gear pumps & mixers)
✔ ParFloat^® – PTFE Lip Seal for Agitators & Mixers

By choosing high-quality mechanical seals like Parjet’s ParSeries®, ensuring proper installation, and conducting regular maintenance, you can minimize downtime, reduce costs, and enhance equipment efficiency.

Contact Parjet today to learn more about our ParSeries^® Mechanical Seals and how we can customize a solution to fit your specific needs!