Mechanical seal leakage is a common concern in pumps and other rotating equipment used across industrial applications. Even minor leakage can indicate problems with seal selection, installation, operating conditions, equipment alignment or component wear.

A mechanical seal is designed to control leakage between rotating and stationary components of equipment. When the sealing system is not operating under suitable conditions, leakage can increase and may eventually affect equipment reliability and production.

Understanding the actual cause of mechanical seal leakage is therefore important. Replacing the seal without identifying the underlying problem may only provide a temporary solution.

In this guide, we look at common causes of mechanical seal leakage and practical ways to troubleshoot and prevent recurring seal problems.

What Is a Mechanical Seal?

A mechanical seal is a precision sealing device commonly used in pumps, mixers, agitators and other rotating equipment to control fluid leakage around a rotating shaft.

Mechanical seals are available in different designs depending on the equipment and operating conditions.

Common types include:

• Multi Spring Seals
• Wave Spring Seals
• Bellows Seals
• Axial Spring Seals
• Cartridge Seals
• Agitator Seals
• Split Seals

Accura Seals & Engineering currently offers these and other mechanical sealing solutions for industrial applications.

The correct seal should be selected based on the application rather than simply the equipment name or dimensions.

Why Is Mechanical Seal Leakage a Problem?

Uncontrolled leakage can affect equipment performance and maintenance requirements.

Depending on the application, leakage may lead to:

• Product loss
• Equipment contamination
• Increased maintenance
• Reduced equipment reliability
• Unplanned downtime
• Safety concerns
• Premature seal failure

For this reason, identifying the source of leakage early can help prevent more serious equipment problems.

Common Causes of Mechanical Seal Leakage

1. Incorrect Installation

Improper installation is one of the most common reasons for premature mechanical seal problems.

Damage to sealing faces, O-rings or other components during installation can affect sealing performance.

Installation should always follow the manufacturer’s recommended procedure and dimensions.

2. Incorrect Seal Selection

A mechanical seal must be suitable for the actual operating environment.

Important selection parameters include:

• Fluid type
• Pressure
• Temperature
• Shaft diameter
• Shaft speed
• Equipment type
• Chemical compatibility
• Presence of solids or particles

Selecting a seal only by size without considering these operating conditions can result in premature failure.

3. Damaged Sealing Faces

Mechanical seal faces require precision and proper operating conditions.

Scratches, cracks, contamination or excessive wear can prevent the sealing faces from maintaining the required sealing interface.

Possible causes include:

• Improper handling
• Dry running
• Contamination
• Excessive temperature
• Incorrect installation
• Excessive operating conditions

4. Dry Running

Mechanical seals can be seriously affected when equipment operates without adequate liquid around the sealing faces.

Dry running may generate excessive heat and damage sealing components.

To reduce this risk, the pump should operate under suitable conditions and should not be allowed to run without the required process fluid.

5. Excessive Pressure or Temperature

Every mechanical seal design has specific operating limits.

For example, Accura’s ARB04/ARB04A bellows seal is specified for pressure up to 10 kg/cm², speed up to 10 m/s and temperatures from -15°C to +200°C, with temperature capability depending on the secondary seal material. Actual suitability depends on the complete sealing system and application.

Therefore, operating conditions should always be checked against the technical specifications of the selected seal.

6. Shaft Misalignment and Equipment Problems

Mechanical seal problems may sometimes originate from the equipment rather than the seal itself.

Before replacing a leaking seal, inspect:

• Shaft runout
• Shaft alignment
• Bearings
• Coupling
• Pump condition
• Equipment vibration

If the underlying mechanical problem remains unresolved, a replacement seal may also experience premature failure.

 

7. Incorrect Secondary Seal Material

O-rings and other secondary sealing components must be compatible with the process fluid and operating temperature.

An unsuitable material can deteriorate, swell, harden or lose its sealing properties.

Material selection should therefore be based on the actual application conditions.

 

Applications of Mechanical Seals

Mechanical seals are used across many industries where rotating equipment handles liquids or other process fluids.

Common applications include:

• Chemical processing
• Food & pharmaceutical
• Water treatment
• Petrochemical
• Manufacturing
• Maritime
• Pumping systems
• Industrial processing equipment

Accura currently identifies Chemical, Food & Pharma, Water Treatment and Maritime among its served sectors.

 

How to Choose the Right Mechanical Seal

Choosing the right mechanical seal requires more than knowing the pump model.

Consider the following factors:

• Fluid Type

Identify the liquid or process medium and determine its chemical characteristics.

• Pressure

Check both normal and maximum operating pressure.

• Temperature

Consider the normal operating temperature as well as possible temperature peaks.

• Shaft Size and Speed

The shaft diameter and rotational speed affect seal design and operating suitability.

• Equipment Type

The appropriate seal design can vary between centrifugal pumps, mixers, agitators, lobe pumps and other equipment.

• Material Compatibility

Seal faces, elastomers, springs and other components must be suitable for the operating environment.

 

Accura Seals Solutions for Industrial Applications:

Accura Seals & Engineering offers a broad range of mechanical sealing solutions, including Multi Spring Seals, Wave Spring Seals, Bellows Seals, Axial Spring Seals, Cartridge Seals, Agitator Seals and Split Seals.

The website also provides application-specific information and related products for sectors such as Food & Pharma, where sealing systems may need to withstand demanding CIP/SIP processes and challenging temperatures and chemical conditions.

Internal Links :

Mechanical Seals: www.accuraseals.com

Wave Spring Seals: https://www.accuraseals.com/Products/19/Wave-Spring-Seal%20-WS70-%2F-AWS71

Bellows Seals: https://www.accuraseals.com/Products/31/bellows-seals--pnl

Food & Pharma: https://www.accuraseals.com/Sectors/1/food-pharma

Contact Us: info@accuraseals.com

 

How to Prevent Mechanical Seal Leakage

A few basic practices can help improve sealing reliability.

• Follow Proper Installation Procedures
• Keep sealing faces clean and follow the recommended installation dimensions.
• Avoid Dry Running
• Ensure the equipment has suitable operating conditions before starting.
• Monitor Equipment
• Regularly check:
• Leakage
• Vibration
• Temperature
• Pressure
• Shaft condition
• Bearing condition
• Use the Correct Seal

Select the seal according to the actual process conditions rather than relying only on equipment dimensions.

Investigate Repeated Failures

If a newly installed seal repeatedly fails, investigate the equipment and operating conditions instead of continuously replacing the seal.

 

Frequently Asked Questions

What is the most common cause of mechanical seal leakage?

Common causes include incorrect installation, unsuitable seal selection, damaged sealing faces, dry running, excessive operating conditions and equipment misalignment.

Can mechanical seal leakage be prevented?

In many applications, leakage can be reduced by selecting the correct seal, following proper installation procedures, maintaining suitable operating conditions and monitoring equipment condition.

How do I select the right mechanical seal?

Consider fluid type, pressure, temperature, shaft size, speed, equipment type, material compatibility and other application-specific requirements.

Can a mechanical seal fail because of pump problems?

Yes. Shaft runout, misalignment, vibration, worn bearings and other equipment problems can contribute to premature mechanical seal failure.

Does Accura provide different types of mechanical seals?

Yes. Accura’s current product range includes Multi Spring, Wave Spring, Bellows, Axial Spring, Cartridge, Agitator and Split Seals.

 

Conclusion

Mechanical seal leakage should not always be treated as a simple seal replacement issue. The actual cause may be related to installation, seal selection, operating conditions, sealing materials or the condition of the equipment.

A systematic approach to seal selection, installation, inspection and maintenance can help improve equipment reliability and reduce recurring leakage problems.

For application-specific requirements, selecting a mechanical seal based on the actual operating conditions is essential.

 

Need the Right Sealing Solution?

Looking for a suitable mechanical seal for your pump or industrial equipment?

Contact Accura Seals & Engineering for technical assistance and application-specific sealing solutions.

Contact us: 

Website: www.accuraseals.com

Email: info@accuraseals.com

WhatsApp/phone: 9920374837