Expanded PTFE Sheet
Expanded PTFE Sheets are made from 100% virgin PTFE resins. Expanded PTFE sheet using a special process that produces a uniform and highly fibrillated microstructure with a great lot of fibres running in multi-direction. It is food approved product and has excellent resistance to a wide range of chemicals, making it a popular sealing material in the food, drink, and pharmaceutical industries. It has excellent sealability, cuts easily, and separates cleanly from flanges after use.
Expanded PTFE Gasket
Expanded PTFE Gasket is cut from Expanded PTFE gasket sheet, our expanded PTFE gasket sheet made with only pure PTFE resins. It is suitable for use in steel flanges as well as flanges where a highly compressible gasket is required. Expanded PTFE Gasket is also suitable for sealing flanges with irregular surfaces. It will not exhibit the cold flow problems associated with virgin PTFE or the hardness problems of some other filled PTFE products. It has excellent sealability, cuts easily, and separates cleanly from flanges after use
Expanded PTFE Joint Sealant
Expanded PTFE joint sealant tape is a new soft tape gasket product made of 100% PTFE. which is developed by using a highly specific treatment on the PTFE Fluorocarbon material. It is a form-in-place gasket, so it nearly can be used on any sealing surface. Especially for the irregularities and damaged flange surface. It is supplied with a self-adhesive backing for easy fitting.
Expanded PTFE Valve Stem Packing
Expanded PTFE Valve Stem Packing is engineered through an expansion process, which provides absolute reliability, chemical resistance, and the lowest total cost of ownership. It eliminates stem wear, resists chemical attack, and performs reliably across extreme temperatures
Expanded PTFE Manufacturers FAQ
Expanded PTFE Sealing Solutions
ePTFE Products for Difficult Flanges and Demanding Process Conditions
Expanded PTFE is widely used where a flange connection needs PTFE’s chemical resistance but also requires a softer, more adaptable sealing material. LongSeal supplies an expanded PTFE product range for different sealing applications, including:
Expanded PTFE Sheet for gasket cutting and conversion
Expanded PTFE Gaskets for ready-to-install flange sealing
Expanded PTFE Joint Sealant for large, irregular and non-standard flanges
Expanded PTFE Valve Stem Packing for selected valve and equipment sealing applications
The correct selection depends on flange construction, available sealing size, surface condition, bolt load and how the gasket will be fabricated and installed
Choose Expanded PTFE by Sealing Requirement
Different ePTFE product forms solve different purchasing and installation requirements.
| Product | Supply Form | Suited For |
|---|---|---|
| Expanded PTFE Sheet | Sheet stock | In-house gasket cutting and gasket converters |
| Expanded PTFE Gasket | Finished gasket | Ready-to-install standard or custom flange sealing |
| Expanded PTFE Joint Sealant | Continuous tape | Large, irregular and non-standard flanges |
| Expanded PTFE Valve Stem Seal | Packing/cord | Selected valve stem and equipment sealing |
Where Expanded PTFE Adds Value
Flanges with Limited Available Gasket Stress
Some flange systems cannot safely accept the same assembly load as heavy steel piping.
A soft ePTFE material can establish sealing contact under relatively low gasket stress, making it useful for selected glass-lined, FRP, plastic and other stress-sensitive connections.
The allowable bolt load should always be determined by the flange or equipment design.
Rough or Imperfect Sealing Faces
Older equipment may have machining marks, minor corrosion, scratches or local surface variation.
Because expanded PTFE is highly conformable, it can adapt to minor surface irregularities more effectively than relatively rigid sealing materials. However, do not use ePTFE as a substitute for repairing severely damaged or structurally unsuitable flanges.
Chemically Aggressive Process Media
PTFE is selected extensively in chemical processing because of its broad resistance to aggressive media.
Expanded PTFE maintains the chemical advantages of PTFE while providing a structure better suited to compressible flange sealing.
Actual compatibility should be confirmed against the specific process medium, concentration and operating temperature.
Large and Non-Standard Equipment
Large vessels, heat exchangers, manways, rectangular covers and custom equipment can require gasket dimensions that are inconvenient to manufacture, ship or keep in inventory. Expanded PTFE sheet and joint sealant provide flexible alternatives for these applications.
Applications Sensitive to Creep and Bolt-Load Loss
Unmodified PTFE can deform under sustained compression. Suitable engineered ePTFE gasketing can provide better dimensional characteristics and resistance to excessive creep, helping maintain a more stable flange connection.
Selecting ePTFE for Different Flange Systems
Steel Flanges
For standard steel piping and equipment, ePTFE sheet or finished gaskets can provide a practical chemically resistant sealing solution.
Selection should consider flange finish, gasket width, bolt load and service conditions.
Glass-Lined and Enamelled Equipment
Glass-lined equipment requires careful control of gasket compression because excessive or uneven assembly load can damage the lining.
Soft ePTFE materials can be useful where conformity and controlled gasket stress are important.
FRP and Plastic Flanges
FRP and thermoplastic flanges generally have less rigidity than heavy metallic flanges.
Material compressibility, gasket thickness and bolt load therefore become particularly important when selecting a sealing system.
Large Equipment Flanges
For tanks, vessels, exchangers and other large equipment, both sheet gasketing and joint sealant can be considered.
The decision generally depends on whether a one-piece finished gasket or a form-in-place sealing method is more practical.
Material Structure Matters
Not all expanded PTFE products are manufactured in the same way. Depending on the product, ePTFE can have different fibril orientation and strength characteristics.
Multi-Directional ePTFE
A multidirectional structure can provide improved strength balance across more than one direction and can help limit lateral spreading under compression.
This can be useful where:
The sealing face is narrow
Gasket width needs to remain controlled
Dimensional stability is important
The flange is sensitive to gasket movement
Mono-Directional ePTFE
Mono-directionally expanded PTFE is widely used in certain form-in-place joint sealant products because it provides excellent flexibility and adaptability around large or complex flange geometries.
Expanded PTFE or Pure PTFE?
Pure PTFE May Be Selected When
A dense PTFE component is required
The part is machined rather than compressed as a gasket
Dimensional rigidity is more important than conformability
The application is not primarily a flange gasket
Expanded PTFE May Be Selected When
The gasket must conform to the flange surface
Low gasket stress is desirable
Minor flange irregularities need to be accommodated
Creep and bolt-load retention are important concerns
Large or irregular gasket geometry is involved
The exact selection should still be based on the complete flange and operating conditions.
Application Information We Recommend Checking
Before selecting an ePTFE sealing product, consider the following:
Flange Material
Steel, stainless steel, glass-lined steel, FRP and plastic flanges have different rigidity and bolt-load limitations.
Available Sealing Width
This is particularly important for joint sealant and narrow flange faces.
Surface Condition
Minor surface variation may be accommodated by ePTFE, while significant damage may require flange repair.
Operating Medium
Confirm the process chemical and concentration.
Temperature and Pressure
These values should be evaluated together with the flange design, gasket dimensions and available bolt load.
A material’s theoretical maximum temperature should not automatically be treated as the maximum safe operating temperature of every flange connection.
Installation Method
Determine whether the customer needs:
Sheet
A finished gasket
A form-in-place joint sealant
Stem seal material
This often decides the suitable product before technical specifications are compared.
Manufacturing and Supply Support
LongSeal supports both material supply and finished-gasket conversion.
Our ePTFE supply capabilities include:
Expanded PTFE sheet production
Standard and custom dimensions
Finished gasket cutting
Drawing-based gasket fabrication
Joint sealant processing
Different roll sizes
Batch identification
OEM packaging
Quality inspection focuses on properties relevant to the individual product, including dimensions, thickness, surface condition, material consistency and finished-product appearance.
For repeat industrial supply, specifications can be confirmed before production to maintain order-to-order consistency
For Gasket Manufacturers and Distributors
Expanded PTFE sheet is suitable for customers who require material for their own gasket production.
We can discuss:
Standard sheet sizes & Thickness
Bulk quantities
Private labeling
Packaging
Regular purchasing schedules
Finished custom gaskets can also be supplied
For Maintenance and End Users
If you are replacing an existing gasket and are unsure which ePTFE format is appropriate, send us:
A flange drawing
Existing gasket dimensions
Process medium & Quantity
We can then judge whether sheet material, a finished gasket or joint sealant is the more suitable option.
Find the Right Expanded PTFE Product
Choosing the correct ePTFE product starts with the sealing applications.
If you need material for gasket production, choose Expanded PTFE Sheet.
If you require ready-to-install components, choose Expanded PTFE Gaskets.
If the flange is large, irregular or difficult to fabricate as one piece, consider Expanded PTFE Joint Sealant.
Send us your flange information and operating conditions if you need help selecting the most practical solution