Expanded PTFE Gasket
Expanded PTFE gaskets are soft, highly conformable industrial sealing gaskets manufactured from expanded polytetrafluoroethylene (ePTFE).
The expanded structure combines the broad chemical resistance of PTFE with improved compressibility, flexibility and dimensional stability, making ePTFE gaskets particularly suitable for industrial flanges where surface irregularities, limited bolt load or aggressive process media make sealing more challenging.
We manufacture finished expanded PTFE gaskets from ePTFE sheet material in standard and custom dimensions, including ring gaskets, full-face gaskets, large-diameter gaskets and irregular shapes.
Gaskets can be supplied according to flange dimensions, industry standards, customer drawings or samples.
Material: Expanded PTFE
Available Forms: RF, FF, ring and custom-cut gaskets
Dimensions: Standard and custom sizes
Custom Cutting: Available
Drawing-Based Production: Available
What Is an Expanded PTFE Gasket?
An expanded PTFE gasket is a finished static sealing component manufactured from ePTFE gasket material and cut to match a specific flange or equipment geometry.
The expansion process creates a network of PTFE fibrils rather than the relatively dense structure of conventional molded or skived PTFE. This gives the gasket a softer, more compressible structure that can conform closely to the sealing surface when the flange is assembled.
The material retains the broad chemical resistance associated with PTFE while offering sealing characteristics particularly suited to industrial gasketing.
Expanded PTFE gaskets are commonly selected for:
Chemical process piping,Steel equipment flanges, Glass-lined equipment, Selected FRP and plastic flanges, Heat exchangers, Pumps and valves, Pressure vessels,Manways and equipment covers, Custom and irregular flange connections
Why Choose Expanded PTFE Gaskets?
The main advantage of ePTFE is not simply that it is PTFE. Its expanded structure changes how the material behaves under flange compression.
Excellent Surface Conformability
Expanded PTFE is soft enough to adapt to minor flange roughness, waviness, scratches and other surface irregularities. This helps the gasket establish more uniform contact across the sealing surface and can be particularly useful where flange condition is less than ideal. Severely damaged or structurally unsuitable flanges should still be repaired rather than compensated for solely by gasket material.
High Compressibility
ePTFE compresses readily under flange load. This makes it useful for selected flange systems where excessive gasket stress is undesirable or where available bolt load is limited..
Improved Dimensional Stability
The expanded PTFE structure provides improved resistance to the creep and cold-flow behavior commonly associated with conventional unmodified PTFE. Better dimensional stability helps the gasket maintain its geometry during service and reduces excessive deformation under sustained compression..
Excellent Chemical Resistance
Because the gasket is based on PTFE, it provides broad resistance to acids, alkalis, solvents and many other aggressive industrial process media. Chemical compatibility should always be evaluated according to the actual medium, concentration and operating temperature.
Clean PTFE-Based Construction
Expanded PTFE gaskets contain no rubber binder. Suitable grades can be supplied for applications where clean PTFE-based sealing material and supporting compliance documentation are required.
Easy Removal and Replacement
ePTFE gasket material generally separates cleanly from suitable flange surfaces, helping simplify gasket replacement during maintenance.
Custom Expanded PTFE Gasket Manufacturing
As both an expanded PTFE material supplier and gasket manufacturer, we can provide finished sealing gaskets instead of requiring customers to source sheet material and arrange cutting separately.
Our custom gasket service can include:
Material selection
Sheet thickness selection
Dimensional review
RF gasket cutting
FF gasket cutting
Standard flange dimensions
Non-standard dimensions
Irregular shapes
Small- and large-batch production
Drawing-based manufacturing
Custom packaging and identification
Expanded PTFE Gasket Types and Sizes
We manufacture expanded PTFE gaskets in standard and customized shapes, they are
availabe in RF, FF,Standard Flange Gasket, Large-diameter gasket, Custom and Irregular Gaskets.
Expanded PTFE gaskets can be manufactured from ePTFE sheets in a range of standard thicknesses, the common thickness are range from 0.5mm to 10mm. Gasket diameter and dimensions depend on sheet size, gasket forms and manufacturing method
Expanded PTFE Gasket Technical Data
PROPERTY | STANDARD | VALUE |
Color | – | White |
Density | ASTM D792 | 0.75-0.95g/cm3 |
Operating temperatures | – | -286 – 320°C |
Compressibility | ASTM F36 | 45 % |
Recovery | ASTM F36 | 12 -13% |
Creep Relaxation | ASTM F38 | 35 – 36 % |
Sealability (Nitrogen) | ASTM F 37B | 0.15 ml / hr |
Sealability (Fuel A) | ASTM F 37B | 0.02 ml / hr |
Service Pressure | – | Full Vaccum to 19 MPa |
Tensile Strength Both directions | ASTM D638 | 19.6 MPa |
Note: Max temperature and pressure capability depends on flange design, gasket dimensions, gasket stress, process medium and installation conditions
Which Flanges Are Suitable for Expanded PTFE Gaskets?
One of the advantages of expanded PTFE is its ability to work with a variety of industrial flange materials and surface conditions.
Steel and Stainless Steel Flanges
ePTFE gaskets are suitable for many process piping and equipment connections requiring chemical resistance and good surface conformity.
Glass-Lined Steel Flanges
Glass-lined equipment can be sensitive to excessive mechanical loading. The high compressibility of expanded PTFE makes it useful for selected glass-lined flange applications where a soft gasket material and controlled sealing load are required. Equipment-manufacturer assembly requirements should always be followed.
FRP and Plastic Flanges
FRP and thermoplastic flange systems typically have lower rigidity and allowable bolt loading than steel flanges. Expanded PTFE can be suitable for selected applications because it can establish sealing contact at relatively low gasket stress. Gasket dimensions, thickness and bolt load must nevertheless be evaluated for the specific flange system.
Flanges with Minor Surface Irregularities
The conformable ePTFE structure can accommodate minor roughness, waviness or surface imperfections more readily than relatively rigid gasket materials. A gasket should not be used to compensate for major flange distortion or structural damage.
Application Industry
Chemical and Petrochemical Processing
Typical applications include process piping, vessels, reactors, pumps, valves and other equipment handling corrosive or chemically aggressive media.
Food and Beverage Processing
Suitable ePTFE grades can be used for relevant food-processing applications where appropriate material compliance documentation is available.
Pharmaceutical and High-Purity Processing
The clean PTFE-based construction makes expanded PTFE useful for selected pharmaceutical and high-purity applications when the required material grade and documentation are specified.
Pulp and Paper
ePTFE gaskets can be used in chemical preparation, bleaching, water treatment and other process equipment requiring corrosion-resistant flange sealing.
Power Generation
Applications can include chemical handling, process piping and auxiliary equipment where PTFE chemical resistance and flange conformability are advantageous.
Marine and General Industrial Equipment:
Expanded PTFE gaskets can be used in pumps, piping systems, vessels, heat exchangers, compressors and other static equipment connections.
How to Select an Expanded PTFE Gasket
Correct gasket selection depends on the complete flange system rather than material type alone.
1. Identify the Flange
Confirm: Flange material
Raised face or flat face Standard or non-standard design Nominal size Pressure class The rigidity and available bolt load of the flange system influence gasket selection.
3. Select an Appropriate Thickness
5. Check Temperature and Pressure Together
2. Determine Gasket Dimensions
For standard flanges, provide the applicable flange standard and size.
For custom gaskets, provide:
ID,OD,Thickness,Bolt-hole information,Drawing where necessary
4. Confirm the Process Medium
6. Specify Compliance Requirements
Expanded PTFE Gasket vs pure PTFE Gasket
| Property | Expanded PTFE Gasket | Pure PTFE Gasket |
|---|---|---|
| Structure | Expanded fibrillated PTFE | Molded or skived PTFE |
| Flexibility | Soft and conformable | Rigid |
| Compressibility | Higher | Lower |
| Flange Conformity | Better suited to minor irregularities | More dependent on good flange flatness |
| Creep / Cold Flow | Reduced compared with unmodified PTFE | More pronounced |
| Limited Bolt Load | Often advantageous | More application-dependent |
| Chemical Resistance | Excellent PTFE resistance | High PTFE resistance |
| Custom Cutting | Excellent | Good |
Expanded PTFE Gasket, Sheet or Joint Sealant?
Our expanded PTFE sealing products are available in three main forms.
Expanded PTFE Sheet
Expanded PTFE Gasket
Expanded PTFE Joint Sealant
Quality Control for Custom ePTFE Gaskets
Reliable finished gaskets require control of both the ePTFE material and the final gasket dimensions. Our production process covers expanded PTFE material preparation, sheet manufacture, gasket conversion and finished-product inspection
Material Control
The expanded PTFE sheet is inspected according to the applicable product specification before gasket production.
Gasket Conversion
After the sheet material is inspected, gaskets are cut according to confirmed dimensions, standards or customer drawings. Depending on product size and order quantity, suitable cutting methods are selected to maintain dimensional accuracy and clean edges.
Finished gaskets Inspection include
Inside diameter Outside diameter Thickness Bolt-hole position Bolt-hole diameter Custom drawing requirements
Custom Supply
We support:Standard and customized dimensions,OEM production Custom packaging,Technical documentation Relevant material compliance documentation where available
Always Will Help You
Frequently Asked Questions
An expanded PTFE gasket is a finished soft sealing gasket manufactured from ePTFE material. Its fibrillated structure provides high softness, compressibility and flange conformity than common pure PTFE.
The material can be the same, but the supply form is different.
Expanded PTFE sheet is supplied as raw gasket material, while an ePTFE gasket is cut to the required dimensions and supplied as a finished product
Yes. We manufacture standard and custom expanded PTFE gaskets according to flange dimensions, drawings or customer specifications.
Common forms include ring, RF, FF, rectangular, oval, irregular custom gaskets
Our ePTFE gaskets are manufactured to standard dimensions including ASME B16.21 (for ASME B16.5 flanges Class 150, 300, and 600) and DIN EN 1514-1 (for PN10, PN16, PN25, and PN40 flanges). We also offer custom manufacturing based on custom drawings.
Filled PTFE gaskets (including silica,glass microspheres, etc) improve creep resistance compared to virgin PTFE but remain rigid. Expanded PTFE (ePTFE) gaskets provide equal or superior creep resistance while remaining extremely soft and flexible, allowing them to conform to damaged flanges with far less bolt torque
Choose the thinnest gasket possible that will fully suit to your flange's surface roughness. Thinner gaskets (1.5mm or 2.0mm) offer maximum pressure resistance and lower creep. Thicker gaskets (3.0mm to 6.0mm) are ideal for heavily pitted, warped, or glass-lined flanges requiring greater compressibility
Neither material is universally better.
Expanded PTFE is generally more conformable and compressible and has improved resistance to creep compared with unmodified PTFE. Pure PTFE remains suitable for many other gasket and engineering applications