A Kaxite PTFE envelope gasket is a composite sealing element: a molded PTFE shell fully encloses a compressed inner core. The shell delivers the same chemical inertness as solid PTFE, while the internal core — non-asbestos, graphite or elastomer — supplies the compression recovery and anti-creep behaviour that solid PTFE cannot achieve on its own. The result is a flange seal that stays tight under thermal cycling, on large or imperfect flanges, and in aggressive media where a single-material gasket would relax or cold-flow.
Manufactured in Ningbo, China by Kaxite Sealing, our envelope gaskets are supplied in three standard profiles — 1320Y, 1320UR and 1320UE — and cut to ASME B16.5, EN 1092-1, DIN, JIS and GB flange standards. OEM/ODM, bulk wholesale and free samples for qualified buyers.
Virgin PTFE, molded around the core to form a seamless envelope. Provides the media-contact surface — chemically inert across pH 0-14, non-stick, non-leaching, FDA-compliant for food and pharmaceutical flanges.
Non-asbestos, graphite or elastomer sheet. Absorbs bolt-load variations and recovers under thermal cycling, preventing the creep-related leaks that solid PTFE gaskets develop over time.
The most widely used profile. Suits low-temperature, low-pressure flanges across chemical, water and general industrial service. Core material selectable by application.
U-shaped profile designed for large-diameter flanges handling toxic or hazardous chemicals. Superior recovery on wide faces where bolt-load distribution is uneven.
Thick-core construction engineered to reduce inner flange residue and improve sealing against thicker or uneven flange faces. Preferred in pharmaceutical and food flanges.
| Attribute | PTFE Envelope Gasket | Pure PTFE Gasket |
|---|---|---|
| Construction | PTFE shell + compressed core | 100% solid PTFE |
| Compression recovery | Excellent (elastic core) | Moderate |
| Anti-creep under bolt load | Excellent | Moderate |
| Temperature range | -100 ~ +260°C | -212 ~ +260°C |
| Max pressure | 50 bar | 86 bar |
| Sealing material purity | Very high | Highest |
| Best for | Large flanges, thermal cycling, hazardous media | High-purity lines, aggressive solvents |
Send flange standard, nominal size, envelope profile and core material — our engineers reply with pricing, lead time and sample availability within 24 hours.
Related products: Pure PTFE Gaskets Expanded PTFE Gaskets Modified PTFE Gaskets PTFE Ring Gaskets PTFE Sheets
Address
No 432 Zhenhai Middle Road, Luotuo Street, Zhenhai District, Ningbo City, Zhejiang China
