Kaxite Sealing manufactures pure PTFE gaskets from 100% virgin PTFE resin with no fillers, no pigments and no plasticisers. That means the widest possible chemical compatibility, zero risk of filler leaching into the process, and full FDA 21 CFR 177.1550 / USP Class VI compliance for food, beverage and pharmaceutical contact. We die-cut, CNC-machine and skive gaskets to ANSI B16.21, ASME B16.20, DIN, EN and JIS flange patterns, in thicknesses 0.4 to 6.35 mm. Procurement teams choose us for factory-direct bulk pricing, documented traceability and 7–15 day lead times.
100% virgin PTFE with no fillers, pigments, plasticisers or processing aids. Nothing can be extracted into the process stream — critical for semiconductor UPW, pharmaceutical APIs and food-grade contact.
Inert across pH 0–14, resisting sulfuric and nitric acid, aqua regia, strong bases, halogens and organic solvents. Filled grades can attack from the filler side; pure PTFE cannot.
Cryogenic LNG, liquid nitrogen and helium service through to continuous process steam. Retains flexibility at the low end without becoming brittle; resists heat at the high end.
Standard flange patterns or custom shapes to drawing. Sheet stock 0.4–6.35 mm thick, from skived or molded PTFE. Cut-to-size service reduces your machining waste and lead time.
Die-cut or CNC-machined from 100% virgin PTFE sheet, with no fillers, no pigments and no plasticisers. Designed for flange sealing in chemical processing, pharmaceutical, food and beverage, semiconductor and general industrial service where full-spectrum chemical inertness and zero process contamination are mandatory. Available in standard ANSI B16.21, ASME B16.20, DIN, EN and JIS flange patterns, plus custom sizes to drawing.
| Property | Test Method | Typical Value | Notes |
|---|---|---|---|
| Material | — | 100% Virgin PTFE (unfilled) | No fillers, pigments or plasticisers |
| Density | ASTM D792 | 2.15 – 2.20 g/cm³ | Indicates material purity |
| Tensile Strength | ASTM D638 | 3,000 – 5,000 psi (20.7 – 34.5 MPa) | Withstands handling and bolting |
| Elongation at Break | ASTM D638 | 300 – 500 % | High ductility, resists tearing during die-cutting |
| Coefficient of Friction | ASTM D1894 | 0.05 – 0.10 | Reduces flange torque requirements |
| Continuous Service Temperature | — | -268 to +260 °C | Cryogenic LNG through process steam |
| Dielectric Strength | ASTM D149 | > 400 V/mil | Excellent electrical insulation |
| Water Absorption | ASTM D570 | < 0.01 % | Dimensionally stable in humid service |
| Pressure Rating | — | Up to 150 psi (10.3 bar) | Higher with reinforced or envelope construction |
| Compliance | — | FDA 21 CFR 177.1550 / USP Class VI | For food, beverage and pharmaceutical contact |
Reactor flanges, transfer piping and storage tank connections handling sulfuric acid, hydrochloric acid, caustics and mixed chemical streams where no filler chemistry can be risked.
Fermenters, chromatography columns, WFI lines and CIP/SIP systems requiring USP Class VI biocompatibility and zero extractables. Pairs with PTFE envelope gaskets for higher pressure classes.
Processing lines for dairy, brewing, juice and edible oils where FDA 21 CFR 177.1550 compliance and non-contaminating contact are mandatory.
Wet benches, ultra-pure water distribution and chemical delivery where ultra-low extractables and no particle generation are essential.
Dielectric barriers, insulating bushings and high-frequency circuit isolation where >400 V/mil dielectric strength is required.
Compressors, hydraulic and pneumatic systems, and any corrosive-service flange connection. See our PTFE gaskets overview for related grades.
Superior chemical resistance across the entire pH scale. Fillers like glass, graphite or carbon used in composite gaskets to improve creep resistance or hardness can be vulnerable to specific chemicals. Pure PTFE with no additives provides the broadest possible chemical compatibility, making it the safest choice for unknown or mixed chemical streams. It also guarantees no contamination of the process fluid, which is critical in high-purity industries.
Cold flow (creep) is a characteristic of PTFE where it slowly deforms under sustained pressure. To manage it: use flanges designed for soft gaskets (raised face, tongue-and-groove); follow a proper bolting procedure with initial seating stress; and re-torque bolts after a short period — typically 24 hours of operation or after the first heat cycle — to compensate for initial relaxation. We can advise on gasket thickness and style to minimise the effect for your specific flange.
Pure PTFE has physical limits. For high-pressure systems above 150 psi, we recommend alternative forms such as Kammprofile gaskets with a PTFE sealing layer or envelope gaskets with a robust core, which contain the PTFE and prevent extrusion. Consult our engineering team for high-pressure, high-temperature applications.
Yes — pure PTFE is excellent for oxygen and oxidiser service due to its non-flammable and chemically inert nature. For high-pressure oxygen systems, cleanliness is paramount: any grease, oil or particulate contamination can pose an ignition risk. We can supply gaskets cleaned, bagged and packaged in a controlled environment specifically for critical oxygen service to meet ASTM G93 requirements.
Thickness selection balances flange condition, pressure and bolt load. Thinner gaskets (1/16" to 1/8") offer better creep resistance and suit flat, smooth flanges at lower pressures. Thicker gaskets (1/4" and above) compensate minor flange imperfections or misalignment but require more bolt load and are more prone to creep. For standard raised-face flanges, 1/8" is a common starting point. Our team can advise based on your ASME B16.5 or B16.47 flange details.
Yes. Custom fabrication is a core strength. We produce Pure PTFE Gaskets in virtually any size or complex shape — from large-diameter tank flanges to intricate multi-port designs. We work from customer-supplied drawings, CAD files or physical samples. Capabilities include precision CNC machining, die-cutting and skiving from large blocks or sheets to meet exact dimensional tolerances.
Every shipment ships with an inspection report covering density, thickness and dimensional checks. On request we provide FDA 21 CFR 177.1550 and USP Class VI declarations, RoHS and REACH compliance statements, plus full resin-lot traceability from PTFE resin to finished gasket. Third-party testing (SGS, TÜV) is available on request.
Store flat in a cool, dry place away from direct sunlight and heat. Keep in original packaging until use to avoid contamination from dust or oils, especially for high-purity and food-grade grades. PTFE does not degrade over time — shelf life is effectively unlimited under these conditions.
Send us your flange standard, gasket ID and OD, thickness, quantity or finished-part drawing. Our export team replies within 24 hours and confirms grade selection, lead time, packaging and documentation before you place a bulk order.
