Static Seals


A classic for the future

Static and dynamic sealing at the highest quality level

Endless O-Rings with a circular cross-section: O-Rings are among the sealing classics par excellence. Primarily used for static sealing of inactive machinery components against liquids and gases. Special solutions and special forms from Freudenberg Sealing Technologies are also suitable as dynamic sealing elements, e.g. as piston or rod seals in the hydraulic system.

High-tech seal instead of category C material

FST O-Ringe O-rings

Hallmark of the O-Ring is its diversity. As diverse as its areas of application, from tap fittings to air-conditioning systems, from the car engine to the dental drill, are the requirements that are being placed on it. Depending on the application, the O-Ring must be resistant to ozone, swelling or high temperatures, chemically stable at times, then pressure-resistant or flexible at low temperatures, and in the food industry it needs to be FDA-compliant, i.e. compatibility with foodstuffs is required.

In short, the supposedly simple C part has evolved into a high-tech seal. This requires in-depth knowledge of materials and advanced process engineering and quality assurance methods. An example: if necessary, Freudenberg Sealing Technologies can coat the surface of an O-Ring with appropriate powders, specialty greases, emulsions or lacquers. In conjunction with the appropriate gasket material, the classic can thus be optimized for the particular application: reduced wear and tear mean longer durability, not to mention the ease of installation and maintenance of the coated rings.

Standard parts and individual custom designs

FST O-Ringe O-rings

As additional customer benefits, Freudenberg Sealing Technologies offers you the following:

  • A unique, broadly differentiated O-Ring assortment of quickly available standard parts in all prevalent international dimensions.
  • Individually designed special solutions on the basis of several hundred materials. O-Ring seals from Freudenberg Sealing Technologies can be adapted across all industries and market segments to technically demanding installation and operating conditions on a customer-specific basis.
  • Great design variety – special shapes, X- and D-Rings are also on offer.

Encapsulated O-Rings - The covering makes the difference

O-Ring ummantelt

Elasticity with the greatest possible media resistance – encapsulated O-Rings offer outstanding functional reliability in demanding static sealing situations.

The combination of an elastomer O-Ring and a closed encapsulation made of modified PTFE makes encapsulated O-Rings from Freudenberg Sealing Technologies an ideal sealing component for contact with aggressive media: with simultaneously high elastic behavior for an optimal contact pressure,the kind that only an elastomer can provide.

Depending on the temperature resistance needed, either FKM or VMQ is used as the core material. The encapsulation consists of FEP or PFA.

The range of application focuses exclusively on static sealing due to the encapsulation. Encapsulated O-Rings are available in nearly all desired sizes, inner diameters and ring thicknesses, in metric or imperial dimensions. Both the encapsulation and, if desired, the elastomer core are FDA-compliant.

Our products in detail

FST O-Ringe O-Rings D-Ringe D-Rings


FST O-Ringe O-Rings D-Ringe D-Rings


FST O-Ringe O-Rings Oval-Ringe Oval Rings


FST O-Ringe O-Rings Rechteck-Ringe Square Rings

Square Rings

FST O-Ringe O-Rings X-Ringe X-Rings


Related documents



A FEP/PFA-encapsulated O-ring consists of an elastomer core and a seamless sealed cover.


Sealing solutions specially developed for the process industry in accordance with hygienic design and materials with industry-specific approvals.

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