Encapsulated O-Rings
Encapsulated O-rings are specially engineered seals designed to address a common challenge across various industries. In many applications, there is a need for the chemical and temperature resistance of PTFE, yet a standard PTFE O-ring lacks the flexibility required for effective compressive fluid sealing. Conversely, while elastomeric materials offer the necessary flexibility, they often fall short in terms of chemical resistance.
An encapsulated O-ring offers the best of both worlds. The outer jacket, typically made from Teflon, provides excellent thermal stability and resistance to aggressive chemicals, while the elastomeric core delivers the compressibility and elasticity essential for reliable sealing performance.
Encapsulated O-rings are available with either FEP or PFA Teflon® polymer encapsulation. Both materials offer broadly similar performance characteristics; however, PFA provides superior heat resistance at temperatures exceeding 200°C. For continuous operating temperatures below 205°C, FEP encapsulation is generally the preferred standard.
The core of the O-ring is typically made from either DuPont™ Viton® or high-temperature silicone, depending on the specific application requirements.
A precise moulding process is vital to maintaining the quality and operational integrity of these encapsulated rings. Our rigorous procedures ensure that the most exacting dimensional tolerances are consistently met, with particular attention given to the internal diameter (I.D.) and cross-sectional profile. Any deviation from these tolerances, especially irregularities in the cross-section, can significantly compromise the O-ring’s sealing capability.
Why choose us for your Encaps?
Our encapsulated O-rings deliver a reliable, high-performance sealing solution for applications where aggressive chemicals, elevated temperatures or strict regulatory standards make conventional elastomers unsuitable. They are widely used in sectors such as food processing, where FDA compliance and resistance to harsh cleaning agents are essential.
Key Advantages
- Elastomer-driven resilience paired with the superior chemical resistance, inertness and purity of FEP / PFA.
- No cold‑flow issues thanks to the energising elastomer core—an advantage over solid PTFE rings.
- Cost-effective performance offering a practical alternative to high-priced Perfluoroelastomer (FFKM) seals.
- Flexible manufacturing capability enabling production of virtually any cross-section, diameter or custom geometry.
- Full production traceability supported by multi-stage automated inspection for consistent quality and reliability.
Why Choose Vulcan Seals Chem-Ring® FEP / PFA Encapsulated ‘O’-rings?
Our encapsulated ‘O’-rings provide a high performance and low-cost sealing solutions for a variety of chemically demanding applications or where regulatory compliance is particularly important. For instance, in the food industry FDA compliance and the ability to with stand harsh cleaning chemicals is a necessity, something that standard elastomers often cannot support.
The combination of elastomers and encapsulation choice enables our encapsulated seals to achieve a combination of temperature, chemical and cost performance unrivalled by pure elastomeric solutions.
The seamless, uniform FEP / PFA encapsulation provides the Chem-Ring® near universal sealing capability.
- Combines the energising properties of elastomers with FEP / PFA superior chemical resistance, inert and high purity characteristics.
- No cold flow problems due to the elastomer core, unlike solid PTFE ring.
- Provides a cost-efficient alternative to expensive Perfluoroelastomer rings.
- Virtually any cross-section and diameter size or shape of seals can be produced to meet your application.
- Full traceability through production and multi-level automated inspection to ensure high product quality and reliability.
- Backed by a stock guarantee of 20,000 product lines on a vast majority of BS ISO 3601-1/AS 568 sizes and most common non-BS/AS sizes, with non-stocked sizes available in short lead times.