Shaft seals – find manufacturers and suppliers

Shaft seals prevent liquids, gases or lubricants from escaping from housings or systems while allowing the rotating or oscillating movement of shafts.

They ensure the operational safety, efficiency and longevity of machines by preventing leaks and keeping out contamination from inside or outside.

Below you will find an overview of the function and types of shaft seals, as well as an overview of their areas of application and their benefits:

How shaft seals work:

Shaft seals work by creating a continuous sealing contact between a rotating shaft and the stationary housing bore or bearing to prevent the loss of lubricants and at the same time prevent the ingress of liquids or dust.

This contact can be supported by elastic sealing lips, O-rings or metal springs that distribute the pressure evenly.

Some shaft seals also combine sliding layer or friction principles, where lubricant forms a thin film between the shaft and the seal, reducing friction and sealing at the same time.

Types of shaft seals:

1. Radial shaft seals:
   The most widely used type. Seal radial movements, e.g. rotating shafts in pumps, motors or gearboxes.
   They are made from a wide variety of materials, often combined with spring lips or metal springs, to withstand a wide range of media and ensure constant contact pressure.
2. Axial shaft seals:
   Seal axial movements or vibrations.
   Used in shaft couplings, gearboxes or special bearing applications. They are also manufactured from a wide variety of materials in combination with spring lips or metal springs to be suitable for a wide range of media.
3. Mechanical seals:
   Consist of two planar surfaces, often made of hard material or ceramic materials between which a liquid film is formed which creates the sealing effect.
   Ideal for high-pressure, high-temperature or aggressive media.
4. Labyrinth seals:
   No direct contact between seal and shaft, but a system of grooves and chambers.
   More commonly used in turbines, fans or compressors at high speeds and temperatures.
5. O-ring seals and combinations:
   Elastic rings that are tensioned radially or axially.
   Often combined with metal or plastic guides for higher loads.

Use of shaft seals:

Shaft seals are found in almost all industries and machines where rotating shafts and media-carrying systems come together:

1. Pumps and compressors:
Prevent leaks of water, oil or gases.

2. Gearboxes and drives:
Keep lubricants in the housing and protect bearings from contamination.

3. Engines:
Sealing of crankshafts and camshafts.

4. Hydraulic and pneumatic systems:
Sealing of piston rods or rotating axles.

5. Food and pharmaceutical industry:
Seals made from FDA-compliant materials for hygienic applications.

6. Turbines and fan systems:
Labyrinth seals to reduce air leakage and energy losses.

Advantages of shaft seals:

• Leakage prevention: protection against loss of liquids, gases or lubricants.
• Operational safety: Prevents damage to machine components due to the escape of media or ingress of foreign bodies.
• Flexibility: Wide range of materials and designs for different media, temperatures and pressures.
• Energy efficiency: Reduced friction losses with optimally matched seals.
• Long service life: High-quality materials and precise manufacturing ensure long-lasting operation.
• Low maintenance: Many seals are durable and require only minimal replacement or readjustment.
• Safe operation in critical environments: Use in high-pressure, high-temperature or corrosive media possible.

Shaft seals are important machine elements that significantly influence the safety, efficiency and service life of systems. Their variety of designs - from elastomer-based radial seals to mechanical seals and labyrinth systems - allows them to be optimally adapted to specific operating conditions.

The following is an overview of the most important points to consider when purchasing shaft seals:

A systematic approach is crucial when purchasing shaft seals, as these components have a significant impact on the operational reliability, service life and efficiency of machines. An incorrect selection can lead to leaks, increased wear or machine failures.

• The basis for the selection is a precise analysis of the application profile:
• Medium: water, oil, aggressive chemicals, air or gases determine the material and seal type.
• Pressure: Low-pressure or high-pressure applications require different sealing principles (radial seals vs. mechanical seals).
• Speed of the shaft: High speed applications require seals with minimal friction and suitable lubrication.
• Temperature range: Materials must be suitable for the operating temperature of the medium and the environment.
• Axial or radial movements: The seal must take into account the direction of movement of the shaft.
• Ambient conditions: Dust, dirt, vibrations or corrosive environments influence material selection and protection systems.
• Radial shaft seals: Standard for rotating shafts, economical and easy to install.
• Mechanical seals: For high pressures, temperatures or aggressive media, precise and durable.
• Labyrinth seals: Contactless, suitable for high-speed applications with low leakage.
• Combinations with O-rings or elastomers: Additional flexibility, damping of vibrations and temperature expansions.
• The choice depends on operating conditions, service life requirements and maintenance intervals.
• Elastomers such as NBR, FKM, EPDM: For standard applications or aggressive media, flexible sealing.
• PTFE or high-performance polymers: High chemical resistance, low friction, also suitable for food and pharmaceuticals.
• Metallic seals: Robust, durable, for high-pressure and high-temperature applications.
• Coatings or surface treatments: Minimize wear, increase friction resistance and tightness.
• Shaft dimensional tolerances: Concentricity, roughness and diameter must meet sealing requirements.
• Fit to the housing: Ensures stable clamping and prevents deformation under pressure or temperature.
• Zero backlash: Particularly crucial in high-precision applications to prevent leakage and wear.
• Easy to install: Simple installation reduces downtimes.
• Lubrication: Internal lubrication can extend the service life of dynamic seals.
• Maintenance intervals: Service life and replaceability must be taken into account in the maintenance concept.
• Demountability: The seal should be easily accessible for maintenance, inspection or replacement.
• Standard-compliant production: ISO, DIN or ANSI facilitate interchangeability and standardization.
• Manufacturer certificates: ISO 9001, FDA (food), ATEX (explosion-proof areas) depending on the area of application.
• Test reports and material certificates: Prove load capacity, chemical resistance and service life.
• In addition to the technical properties, the purchasing department should also keep an eye on cost-effectiveness:
• Life cycle costs: High-quality seals reduce downtime and maintenance costs.
• Availability: Standardized seals ensure the supply of spare parts and avoid production stops.
• Flexibility: Interchangeable or combinable seals reduce the number of variants and storage costs.
• Energy efficiency: Low friction saves drive energy in rotating shafts.
• The quality of a supplier is not only reflected in its products, but also in other factors:
• Technical advice: Support with selection, material and type decisions.
• Special solutions: Adaptation to customer-specific requirements and special media.
• Reliability: Delivery times, stock levels and after-sales service are crucial for continuous operation.
• References: Proof of successful applications in similar industries builds trust.

When purchasing shaft seals, technical specifications, choice of material, fit, ease of maintenance and supplier expertise are crucial. Only through careful analysis of operating conditions and media-dependent requirements can the optimum seal be selected to prevent leaks, minimize wear and maximize machine availability. High-quality, standard-compliant and correctly installed shaft seals are therefore a key factor for the efficiency and longevity of machines and systems.

Shaft seals can be purchased from various suppliers. You will find comprehensive information on manufacturers and suppliers of Shaft seals around the world on Exportpages.