Continuous Support
Solid Silicone Core
Provides continuous internal support and elastic sealing force for static joints where the groove and hardware can apply sufficient compression.
Composite Chemical-Resistant Sealing
FEP Encapsulated Silicone O-Rings
A fluoropolymer jacket for chemical exposure. A silicone core for elastic sealing force.
- Solid or hollow silicone core options
- Custom inside diameters and finished cross-sections
- Application-specific chemical and temperature review
- Inspection and documentation defined by specification
Composite Construction
FEP Encapsulated Silicone O-Ring Construction
An FEP encapsulated silicone O-ring combines a continuous fluoropolymer jacket with an elastic silicone rubber core. The FEP jacket forms the process-contact surface and provides broad chemical resistance, while the silicone core supplies sealing preload, compression, and recovery inside the groove. Jacket integrity is part of the functional seal specification.
The construction primarily serves static axial or radial sealing. Inspection covers jacket continuity, finished cross-section, wrinkles, splits, and installation damage. Core construction changes compression force, recovery, support under load, and installation response. Slow or limited movement requires review of the contact surface, pressure, and jacket-damage risk.
Core Selection
Solid vs. Hollow Core FEP Encapsulated O-Rings
The complete seal is specified as a jacket-and-core combination. Selecting only the FEP jacket or only the silicone grade does not define the finished product.
Reduced Compression Force
Hollow Silicone Core
Can reduce the force required to compress the seal where clamping load is limited or mating components are sensitive to contact pressure.
Custom Dimensions
Custom FEP Encapsulated O-Ring Sizes and Specifications
Groove evaluation uses finished seal dimensions (inside diameter: nominal or drawing-controlled finished ID; finished cross-section: measured after encapsulation; outside diameter: specified when required by the assembly). Standard references provide a starting point; availability and tolerances are confirmed at quotation. Pressure capability depends on the complete seal construction, groove, clearance, media, temperature, and assembly condition.
| Specification | Description |
|---|---|
| Product type | FEP encapsulated silicone O-ring |
| Outer material | Continuous FEP fluoropolymer jacket |
| Core material | Silicone rubber, solid or hollow construction |
| Standard profile | Circular O-ring profile |
| Size definition | ID × finished CS, standard reference, or custom drawing |
| Size references | AS568, ISO 3601, BS 4518, metric, and inch references |
| Preferred duty | Static axial or radial sealing |
| Inspection | Drawing, purchase specification, or agreed inspection plan |
Application Review
FEP Encapsulated O-Ring Chemical Resistance and Temperature
The FEP jacket provides broad chemical resistance, but selection must account for mixed media, concentration, heat, pressure, cleaning cycles, and exposure duration. Molten alkali metals, fluorine, and certain reactive halogen compounds are known exceptions; jacket damage can also expose the silicone core to the process media. A PFA jacket is an alternative when the process requires a higher temperature range; the core and finished seal still need separate review.
- Chemical identity
Name, concentration, and every component of mixed media
- Temperature cycle
Continuous, peak, heating, cooling, and thermal cycling
- Pressure or vacuum
Operating range, direction, clearances, and pressure changes
- Exposure pattern
Duration, cleaning cycles, abrasive particles, slurries, and permeation concerns
Groove and Assembly
FEP Encapsulated O-Ring Groove Design and Installation
FEP encapsulated O-rings are less flexible than conventional solid silicone O-rings. The groove and installation path must accommodate the finished seal without excessive stretch, twisting, or sharp contact. A groove based only on standard elastomer data may not provide the required compression, while high-speed rotary, reciprocating, or abrasive duty requires a different sealing review.
Groove Review
Installation Control
Typical Applications
Applications for FEP Encapsulated Silicone O-Rings
The industry name does not define the seal specification. Each application still requires its own core, finished dimensions, documentation, and test plan.
Chemical Processing
Reactor vessels, access covers, process connections, and secondary seals.
Pumps and Valves
Static joints, housings, covers, and connections exposed to process fluids.
Filtration and Heat Exchange
Cartridge housings, filter covers, heat exchangers, and service access points.
Pipelines and Flanges
Non-abrasive static interfaces where a resilient fluoropolymer-contact seal is needed.
Food, Pharma, and Laboratory
Equipment requiring exact material grades and application-specific compliance documents.
High-Purity Fluid Handling
Specialty gas, semiconductor, and controlled-fluid systems after purity and permeation review.
Quality Control
FEP Encapsulated O-Ring Inspection and Quality Control
The inspection plan should cover finished dimensions, the specified FEP or PFA jacket condition, material identity, and records matched to the purchase specification. Visual inspection alone does not establish chemical compatibility, pressure capability, leakage performance, or service life; critical performance requires a separately defined test method and acceptance criterion.
Dimensional Inspection
Inside diameter, finished cross-section, specified outside diameter, tolerances, roundness, profile, and reference-groove fit when required.
Jacket and Surface Inspection
Continuity, cracks, splits, pinholes, exposed core, wrinkles, creases, deformation, contamination, joint condition, and handling damage.
Material and Documentation
FEP or PFA jacket and silicone core identification, core construction, traceability, specified certificates, inspection reports, regulatory documents, and packaging records.
Jacket Selection
FEP vs. PFA Encapsulated Silicone O-Rings
Both jackets provide broad chemical resistance. The choice starts with temperature, exact media, groove, and required documentation. Resin temperatures are material references; the finished seal's continuous-use limit depends on the silicone core, media, pressure, and compression. Both constructions primarily serve static sealing; slow movement requires a wear and installation review.
| Selection factor | FEP jacket | PFA jacket |
|---|---|---|
| Jacket material temperature reference | About 200°C for continuous use of FEP resin | About 260°C for continuous use of PFA resin |
| Chemical exposure | Broad resistance; confirm the exact media, concentration, and temperature | Broad resistance; confirm the exact media, concentration, and temperature |
| Compression and movement | Core design, jacket thickness, groove, and load determine sealing response | Core design, jacket thickness, groove, and load determine sealing response |
| Typical starting point | Static pump, valve, and chemical equipment seals within the FEP temperature range | Higher-temperature process equipment; high-purity duties need separate cleanliness and documentation review |
Need Custom FEP Encapsulated Silicone O-Rings?
Send the media, temperature, pressure, groove, finished dimensions, and expected volume. Fecision will review the jacket, core, and inspection requirements before quoting.