How to Store a Mechanical Seal

Mechanical seals are critical components in various industrial applications, such as centrifugal pumps, and their correct operation depends on maintaining their integrity during storage. This article will provide a comprehensive guide on the ideal storage environment and procedures for mechanical seals based on the storage duration.

Ideal Storage Environment

To preserve the quality and functionality of mechanical seals, it is essential to store them in a suitable environment. The following factors should be considered:

• Temperature: Store mechanical seals between 15-25°C (59-77°F) in a temperature-controlled space. Extreme temperatures can cause damage to seal components, particularly secondary seal materials such as elastomers.
• Humidity: Maintain relative humidity below 65% to prevent moisture-related degradation of seal components. High humidity can lead to corrosion and deterioration of metal parts and the breakdown of rubber seals.
• Light: Protect mechanical seals from direct sunlight and UV exposure to prevent degradation of seal materials. Store them in opaque containers or in areas without direct light exposure.
• Cleanliness: Use a clean, dry, and well-ventilated storage area free from contaminants such as pumped products, solvents, oils, and copper. Contamination can cause premature seal failure and affect the chemical compatibility of seal materials.
• Ozone: Ensure the storage area is free of ozone and ozone-generating devices and equipment. Ozone can cause cracking and deterioration of elastomeric seal components.

Packaging and Handling

Here are some best practices:

1. Use clean, dry, and airtight containers or bags for packaging mechanical seals.
2. Include desiccant packets or moisture absorbers within the packaging to control humidity levels.
3. Label the packaging with the seal type, size, material, and date of storage for easy identification.
4. Handle seals with clean, gloved hands to prevent contamination and damage.
5. Use soft, lint-free materials for cushioning and separating seals during transportation.
6. Avoid excessive vibration or shock during transportation, which can cause damage to seal components.
7. Store packaged seals in a location that meets the ideal environmental conditions described above.

Storage Procedures Based on Duration

The storage procedures for mechanical seals vary depending on the expected storage duration. Here are the guidelines for short-term and long-term storage:

Short-Term (< 2 Years)

For mechanical seals that will be stored for less than two years, follow these steps:

1. Clean the seal thoroughly, removing any dirt, debris, or process fluids.
2. Inspect the seal for any signs of damage or wear. Replace any worn or damaged components.
3. Lubricate the seal faces and secondary seals with a compatible lubricant to prevent drying and cracking.
4. Package the seal in a sealed, airtight container or bag to protect it from contaminants and moisture.
5. Label the container with the seal type, size, material, and date of storage.
6. Store the seal in a location that meets the ideal environmental conditions described above.
7. Rotate the seal 90 degrees every three months to prevent deformation of the seal components due to prolonged static loading.

Long-Term (> 2 Years)

For mechanical seals that will be stored for more than two years, additional precautions should be taken:

1. Follow steps 1-6 from the short-term storage procedure.
2. Use a vacuum-sealed packaging or nitrogen-purged packaging to minimize oxidation and moisture exposure.
3. Include desiccant packets or moisture absorbers within the packaging to control humidity levels.
4. Rotate the seal 90 degrees every six months to prevent deformation of the seal components.
5. Inspect the seals annually for signs of deterioration or damage. Replace any affected components.

Maintenance During Storage

Even when stored under ideal conditions, mechanical seals require periodic maintenance to ensure their readiness for installation. Here are some maintenance tasks to perform during storage:

1. Inspect seals visually every 6-12 months for signs of deterioration, such as cracking, hardening, or dimensional changes.
2. Rotate seals 90 degrees every 3-6 months to prevent deformation of seal components due to prolonged static loading.
3. Replace any damaged or deteriorated components, such as secondary seals or wear faces.
4. Refresh lubricants on seal faces and secondary seals if they appear dry or hardened.
5. Update the labeling and documentation of seals as necessary, including the date of last inspection and maintenance.

Secondary Seals Shelf Life

The shelf life of secondary seals, such as O-rings and gaskets, is a critical factor in determining the overall storage life of a mechanical seal. The shelf life depends on the type of elastomer used and the storage conditions. Here are some common elastomers and their typical shelf life under ideal storage conditions:

• Nitrile (NBR): 5-7 years
• Fluorocarbon (FKM): 7-10 years
• Ethylene Propylene (EPDM): 5-7 years
• Perfluorocarbon (FFKM): 10-15 years

Wear Faces

The wear faces of a mechanical seal are critical to its performance and should be protected during storage. Follow these guidelines to maintain the integrity of the wear faces:

1. Store the seal with the faces separated by a clean, soft, lint-free material to prevent scratches or damage.
2. Avoid direct contact between the wear faces and any other surfaces or components.
3. Do not stack seals on top of each other without proper separation and protection of the wear faces.
4. Handle the seal carefully during packaging and unpacking to avoid accidental contact with the wear faces.
5. Inspect the wear faces before installation for any signs of damage or contamination. Clean and repair as necessary.