PTFE-Encapsulated O-Ring
O-ring bọc PTFE
Also known as: PTFE jacket O-ring · Teflon encapsulated O-ring · FEP-encapsulated
A PTFE-encapsulated O-ring has a thin PTFE or FEP outer shell (0.2–0.5 mm) over a silicone or FKM core — combining universal chemical resistance with elastomeric recovery for static sealing.
Technical Detail
Structure: 0.2–0.5 mm PTFE or FEP (fluorinated ethylene propylene) outer sleeve bonded or formed over an elastomeric core (typically VMQ silicone or FKM Viton). The PTFE shell contacts the fluid — providing near-universal chemical resistance comparable to solid PTFE sheet. The elastomeric core provides the radial recovery needed to maintain sealing under bolt-load relaxation and thermal cycling. Service temperature: –60°C to +200°C (silicone core) or –20°C to +200°C (FKM core). Pressure: static applications only, ≤7 MPa. Groove design is identical to standard O-ring grooves (AS568 / JIS B2401) but requires 20–25% squeeze (vs 15–20% for solid elastomers) to account for the rigid PTFE skin. Applications: aggressive chemical plant flanges (HCl, HF, chlorine, strong acids), pharmaceutical and semiconductor process connections, and any media that attacks NBR/EPDM/FKM.
Reference Standards
- ASME B16.21
- FDA 21 CFR 177.1550 (PTFE)
Related Terms
- FKM / Viton (Fluorocarbon Elastomer) — FKM (fluorocarbon elastomer, trade name Viton) is a high-performance O-ring material with 66–70% flu…
- VMQ Silicone (Polydimethylsiloxane Rubber) — VMQ Silicone (polydimethylsiloxane) is a flexible, FDA-compliant elastomer operating from –60°C to +…
- AS568 O-Ring Standard (SAE/ANSI) — AS568 (SAE Aerospace Standard) defines 369 standard O-ring sizes in inch dimensions — each identifie…