10 October, 2026 | 
Admin
Crane Hire and Outrigger Pads
Planning a crane lift in Qatar means solvi
Read morePTFE Gasket Guide: Types, Sheet and How to Choose
07 October, 2026 | Admin
Short answer: a PTFE gasket is a seal cut or moulded from polytetrafluoroethylene (PTFE, often sold as Teflon). It is used between flanges and joints where chemicals, high purity or a wide temperature range rule out rubber and fibre gaskets. The main choices are virgin PTFE, filled PTFE, expanded PTFE and envelope gaskets.
PTFE Gasket Full Form
PTFE gasket means a gasket made from polytetrafluoroethylene. “Teflon gasket” is the same thing under the brand name.
Why Choose a PTFE Gasket
- Resists almost all chemicals and solvents
- Wide temperature range, up to about 260 °C for the material
- Does not absorb water and does not contaminate the process
- Suitable for food, pharmaceutical and high-purity use with the right grade
Types of PTFE Gasket
| Type | What it is | Best for | Watch out for |
|---|---|---|---|
| Virgin PTFE | Pure PTFE sheet | Highest chemical purity, food and pharma | Creeps (cold flows) under bolt load |
| Filled PTFE (glass, carbon, graphite, silica, barium sulphate) | PTFE with a filler | Better creep resistance and strength than virgin | Check the filler against the fluid |
| Expanded PTFE (ePTFE) | Soft, porous PTFE | Uneven or delicate flanges, glass-lined equipment, low bolt load | Check pressure rating |
| Envelope gasket | PTFE jacket over a compressible core | Cost-effective chemical sealing with better recovery | Core and envelope design must suit the service |
| Modified PTFE | Improved creep and sealing behaviour | Demanding chemical service | Confirm grade with supplier |
PTFE Gasket Sheet
PTFE gasket sheet is the raw material from which gaskets are cut. It is sold by thickness, commonly in the range of 1.5 to 3 mm, and in different grades. Use PTFE sheet when you need custom shapes, non-standard flanges or small runs. Use ready-cut gaskets for standard flanges. Our guide to ready-cut vs custom PTFE gaskets explains the trade-off.
How to Choose a PTFE Gasket
- Fluid. Confirm compatibility with the process fluid. Choose the filler to suit.
- Temperature and pressure. Match the grade to both.
- Flange type. Flat-face, glass-lined or uneven flanges favour softer materials such as ePTFE.
- Bolt load. Virgin PTFE creeps. Filled or expanded grades hold load better.
- Purity. Food and pharmaceutical use needs the correct certified grade.
- Size and standard. State the flange standard, nominal size, pressure class and thickness when you order. Common references include ASME B16.21 and EN 1514-1.
Installation Tips
- Clean both flange faces.
- Use the correct thickness. Too thick increases creep.
- Tighten bolts in a cross pattern in stages.
- Re-check torque after the first heat cycle where the procedure allows.
- Do not re-use a flattened or deformed PTFE gasket.
PTFE Gasket Selection Examples
- Acid line with standard steel flanges: a filled PTFE gasket, with the filler checked against the acid.
- Glass-lined reactor nozzle: an expanded PTFE or envelope PTFE gasket that seals at low bolt load.
- Food or pharmaceutical line: a virgin PTFE gasket in a certified grade.
Buy PTFE Gaskets and Sheet in Saudi Arabia
Diode Trading EST supplies PTFE sheet and PTFE gaskets from Al Khobar. Send us the flange size, standard and fluid and we will recommend a grade. Every order from Diode Trading EST is supplied with a Material Test Certificate. Request a quote.
Related Guides
Frequently Asked Questions
What is a PTFE gasket?
A gasket made from polytetrafluoroethylene, used to seal flanges where chemical resistance matters.
What is the difference between a PTFE gasket and a Teflon gasket?
None in practice. Teflon is a brand name for PTFE.
What is PTFE gasket sheet?
Sheet material cut into gaskets, available in virgin and filled grades and in several thicknesses.
Which is better, virgin or filled PTFE?
Virgin gives the highest purity. Filled grades resist creep better. Choose based on the fluid and bolt load.
What temperature can a PTFE gasket handle?
Up to about 260 °C for the material. The working limit of the gasket also depends on pressure and design.
Related guides: What Is PTFE? · PTFE Thread Seal Tape Guide · PTFE Coating Guide
Recent Posts
High Visibility Reduce Trip Hazards
See our range of high-visibility safety mats and markers designed to reduce trip hazards across your site.
Related Blogs
