Silica-filled PTFE sheet is light tan or light brown in color. It maintains a tight, reliable seal and exhibits excellent chemical resistance during long-term exposure to strong acids, solvents, and highly corrosive chemical media. Unlike pure PTFE gaskets, it resists creep under load and offers enhanced bolt preload retention.
Key specifications: operating temperature range of -180°C to +200°C, pressure resistance up to 83 bar (1200 PSI), density of 2.1–2.3 g/cm³, and tensile strength ≥20 MPa.
Silica-filled PTFE sheet is a high-performance gasket material made from virgin PTFE reinforced with silicon dioxide (SiO₂) filler. The silica particles provide structural reinforcement that significantly improves the material's sealing performance while maintaining PTFE's broad chemical compatibility (pH 0-14).
This material is specifically designed for use with strong acids, solvents, hydrocarbons, and other aggressive media — making it the preferred choice for chemical processing, pharmaceutical, food and beverage, and petrochemical applications.
Key benefits of silica reinforcement:
Reduced creep relaxation: maintains bolt torque longer, fewer re-torquing requirements
Improved sealing performance: tight seal that reduces product loss and emissions
Excellent chemical resistance: compatible with strong acids (except hydrofluoric acid), solvents, hydrocarbons, chlorine, steam, and cryogenic services
FDA compliant: meets FDA 21 CFR 177.1550 and USDA specifications for food and pharmaceutical applications
Bacterial growth resistant: will not support bacterial growth
Flame resistant: will not support flame
BAM approved: available in oxygen service grade (Style 3502) per BAM standards
EN 12308 certified: cryogenic service certified
|
Problem |
How Silica-Filled PTFE Solves It |
The Cost of Choosing Wrong |
|
Virgin PTFE creeps and loses torque |
Silica reinforces the structure — maintains bolt torque longer, reduces re-torquing |
Frequent re-torquing, gasket replacement every 6-12 months |
|
Strong acids attack standard gaskets |
PTFE provides pH 0-14 resistance — compatible with most aggressive chemicals |
Chemical degradation, seal failure, product loss |
|
Chlorine service degrades rubber |
Silica-filled PTFE resists chlorine — reliable sealing in aggressive media |
Premature failure, safety incidents |
|
Cryogenic service makes materials brittle |
Silica-filled PTFE remains flexible at -180°C — EN 12308 certified |
Brittle failure, leakage in cryogenic systems |
|
Food/pharma contamination risk |
FDA and USDA compliant — pure material, no extractables |
Product contamination, FDA fines, batch loss |
|
Feature |
Silica-Filled PTFE |
Virgin PTFE |
Glass Fiber PTFE |
ePTFE (Expanded) |
|
Creep Resistance |
★★★★★ excellent |
★★☆☆☆ poor |
★★★★☆ |
★★★★☆ |
|
Bolt Torque Retention |
★★★★★ excellent |
★★☆☆☆ poor |
★★★★☆ |
★★★★☆ |
|
Chemical Compatibility |
★★★★★ strong acids (except HF) |
★★★★★ universal |
★★★★☆ not HF/alkali |
★★★★★ |
|
Conformability |
★★★☆☆ |
★★☆☆☆ |
★★☆☆☆ |
★★★★★ |
|
FDA Compliant |
✅ Yes |
✅ Yes |
✅ Yes |
✅ Yes |
|
BAM Oxygen Service |
✅ Yes (special grade) |
❌ No |
❌ No |
⚠️ Limited |
|
Cryogenic Service |
✅ Yes (EN 12308) |
✅ Yes |
✅ Yes |
✅ Yes |
|
Best For |
Strong acids, chlorine, cryogenic |
General chemical |
Abrasive media |
Damaged flanges, low torque |
|
If Your Service Is... |
Choose... |
Why |
|
Strong acids, solvents, hydrocarbons, chlorine |
Silica-Filled PTFE |
Best chemical compatibility + creep resistance |
|
Cryogenic / LNG service |
Silica-Filled PTFE (EN 12308) |
Certified cryogenic performance |
|
Oxygen service |
Silica-Filled PTFE (BAM grade) |
BAM approved oxygen service |
|
Food/pharmaceutical processing |
Silica-Filled PTFE |
FDA compliant, will not support bacterial growth |
|
Badly pitted, warped flanges |
ePTFE (Expanded PTFE) |
Better conformability to irregular surfaces |
|
Abrasive media, high wear |
Glass Fiber PTFE |
Higher wear resistance |
|
Hydrofluoric acid service |
Virgin PTFE |
Silica reacts with HF — virgin PTFE required |
|
Industry |
Application |
Why Silica-Filled |
|
Chemical Processing |
Flanges, pumps, valves — strong acids, solvents, hydrocarbons, chlorine |
pH 0-14 resistance + creep resistance |
|
Pharmaceutical |
Sterile processing equipment — FDA compliance |
FDA 21 CFR 177.1550, non-contaminating |
|
Food & Beverage |
Sanitary connections — FDA/USDA compliance |
FDA compliant, bacteria resistant |
|
Oil & Gas |
Refinery flanges, pipelines — hydrocarbons, aggressive chemicals |
Chemical compatibility + thermal stability |
|
Power Generation |
Steam systems, cooling water — high temperature service |
Wide temperature range, creep resistance |
|
LNG & Cryogenic |
Cryogenic equipment — LNG processing |
EN 12308 certified, -180°C capability |
|
Parameter |
Value |
Notes |
|
Temperature Range |
-180°C to +200°C |
Continuous service |
|
Max Pressure |
Up to 83 bar (1200 PSI) |
Depends on thickness and design |
|
Density |
2.1 – 2.3 g/cm³ |
ASTM D792 |
|
Tensile Strength |
≥20 MPa |
ASTM F152 |
|
Color |
Fawn / light brown |
— |
|
Material |
PTFE + silicon dioxide filler |
SiO₂ reinforced |
|
FDA Compliant |
Yes |
FDA 21 CFR 177.1550, USDA |
|
BAM Approved |
Yes (oxygen grade) |
Style 3502 oxygen service |
|
EN 12308 Certified |
Yes |
Cryogenic service |
|
EU No. 10/2011 |
Yes |
Food contact |
|
Max PxT (1/16") |
350,000 °F x PSIG / 12,000 bar x °C |
— |
|
Max PxT (1/8") |
250,000 °F x PSIG / 8,600 bar x °C |
— |
|
Size (mm) |
Thickness (mm) |
Notes |
|
1500 × 1500 |
0.5 – 10 |
Standard sheet sizes |
|
1500 × 4500 |
Various |
Large sheet available |
|
Custom sizes |
Available on request |
Cut gaskets available |
100% Virgin PTFE Resin — consistent quality, batch after batch
Silica Reinforcement — uniform dispersion for consistent performance
FDA-Compliant — meets FDA 21 CFR 177.1550 and USDA specifications
BAM Approved — oxygen service grade available (Style 3502)
EN 12308 Certified — cryogenic service certified
EU No. 10/2011 — food contact compliant
Full Traceability — material certificates on request
Lead Time — standard sizes in stock (24-48 hours); custom sizes 7-10 days
A: Silica-filled PTFE sheet (also known as SiO₂ PTFE sheet or silica PTFE gasket) is virgin PTFE reinforced with silicon dioxide filler. It offers excellent creep resistance, bolt torque retention, and chemical compatibility, making it ideal for strong acids (except hydrofluoric acid), solvents, hydrocarbons, chlorine, steam, and cryogenic services.
Available in FDA-compliant grades (FDA 21 CFR 177.1550) for food and pharmaceutical applications. BAM approved for oxygen service and EN 12308 certified for cryogenic service.
When NOT to use it: Hydrofluoric acid (HF) service, silica reacts with HF; use virgin PTFE instead.
A: Silica-filled PTFE offers significantly improved creep resistance and bolt torque retention over virgin PTFE. Virgin PTFE is softer and deforms under sustained load, silica-filled PTFE holds its shape longer, reducing product loss and emissions.
Both offer broad chemical resistance (pH 0-14), but silica-filled PTFE is recommended for strong acids, solvents, hydrocarbons, and chlorine service while maintaining FDA compliance (FDA 21 CFR 177.1550).
The unique manufacturing process minimizes cold flow problems typical of conventional PTFE sheets. For cryogenic applications, silica-filled PTFE is EN 12308 certified for service down to -180°C.
When to choose virgin PTFE: Hydrofluoric acid service, applications requiring maximum chemical purity, or lower cost requirements where creep is not a concern.
A: Temperature: -180°C to +200°C continuous service.
Pressure: Up to 83 bar (1200 PSI), depends on thickness and design.
Chemical: pH 0-14, NOT compatible with hydrofluoric acid (HF).
Three common mistakes:
Using in HF service: silica reacts with HF, use virgin PTFE instead
Over-tightening: silica-filled PTFE requires controlled torque; excessive compression can damage the gasket; follow recommended installation torque specifications
Wrong thickness selection: standard sizing available in 1/16" (1.5mm) and 1/8" (3.0mm); follow design specifications. For badly pitted flanges, consider profiled sheet (EPIX®) for improved conformability
Need help selecting the right grade? Contact us with your temperature, pressure, and media, we recommend the right PTFE grade.
Address
No.1028, Qiersan Street, Andong Town, Cixi City, Zhejiang Province, China
Tel
