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Bulk Expanded PTFE Gasket for Chemical, Cryogenic and Low Bolt Load Flanges
Quick Answer: Expanded PTFE gaskets are soft, conformable PTFE sheet gaskets with a microporous structure. Bulk expanded PTFE gasket material is used for chemical service, fragile flanges and low bolt load joints. CORASEALS can supply expanded PTFE gasket sheets, rolls and custom cut gaskets to the dimensions, thickness and flange standard you specify.
Expanded PTFE gasket material is a practical choice for volume users. The expanded structure improves compressibility and reduces the bolt load required to seat the gasket. The material suits plastic flanges, FRP flanges, glass lined equipment and flanges with surface damage or misalignment.
What Is an Expanded PTFE Gasket?
Expanded PTFE is produced by expanding PTFE into a microporous structure. The result is a soft gasket sheet that is more compressible than skived PTFE. It conforms to irregular sealing surfaces and seals at lower gasket stress. The material remains flexible at cryogenic temperatures and resists most industrial chemicals.
Bulk Supply Forms
Bulk supply covers several formats. Common forms include:
- Expanded PTFE sheet in standard sheet sizes
- Expanded PTFE roll in selected widths and thicknesses
- Custom cut gaskets in annular, full face and non standard shapes
For maintenance teams and gasket cutters, sheet and roll formats reduce cutting waste. For OEM production and MRO kits, custom cut gaskets can be packed in exact sizes and quantities.
Performance and Service Limits
Typical expanded PTFE gasket material can operate from -268 °C to 260 °C in continuous service. The actual temperature limit depends on grade, thickness and service fluid. The material has broad chemical resistance to acids, alkalis, solvents and many aggressive chemicals. It is not suitable for molten alkali metals and elemental fluorine in certain conditions.
Expanded PTFE gaskets are generally used on low to medium pressure flanges. Pressure capability depends on sheet thickness, flange design, gasket stress and operating temperature. Thin sheets normally suit higher internal pressure, but thin sheets need better flange surfaces and more accurate installation.
PTFE based gaskets can relax after thermal cycling. Some installations require retorque after the first cycle. Follow the gasket manufacturer instructions for the selected grade.
Applications
Bulk expanded PTFE gasket material is used in chemical piping, acid transfer lines, pharmaceutical equipment, food processing, water treatment, heat exchangers, glass lined reactors, FRP flanges and cryogenic piping. The same material can be supplied as cut gaskets for flange repair work and for equipment where flange surfaces are no longer smooth.
Material Comparison
| Property | Expanded PTFE | Skived PTFE | Filled PTFE |
|---|---|---|---|
| Compressibility | High | Low to medium | Low to medium |
| Conformability | Good on irregular flanges | Limited | Limited |
| Chemical resistance | Broad | Broad | Broad, limited by filler |
| Typical temperature range | -268 °C to 260 °C | -200 °C to 260 °C | -200 °C to 260 °C |
| Common use | Fragile flanges, chemical service, low bolt load | Rigid flanges, general chemical service | Higher load applications, some compressor and pump services |
These values are typical supplier data. The selected grade and data sheet must govern the final gasket choice.
How to Specify and Request a Bulk Quote
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