Best Uses and Applications for Expanded PTFE Gasket Material

October 16th, 2019

Polytetrafluoroethylene, which is also known by abbreviation aficionados as PTFE, is a versatile gasket material. It’s a fluoroelastomer, a synthetic compound that’s available in many forms. On switching over to ePTFE (Expanded PTFE), the carbon-fluorine compound gains new mechanical properties. Classed as a popular sealing material because of a talent for resisting chemical attacks, ePTFE adds greater material conformability and creep resistance to an already impressive set of features.

What is ePTFE?

It’s a synthetic plastic that incorporates all of the features of PTFE while also adding a new set of mechanically improved attributes. That means expanded PTFE operates across a wide range of service temperatures and can shrug off caustic fluid attacks, as imposed by some of mankind’s harshest chemical mediums. On top of that, the plastic is more rubber-like, more conformable and seal-pliable. It goes without saying, but let’s say it anyway; these are the physical attributes that attract the gasketing industry. Resistant to high pressures, high and low temperatures, and material eroding chemicals, PTFE is a desirable gasket medium. Expanded PTFE, on the other hand, retains all of the above features, then it adds mechanical flexibility to an already attractive package.

Expanded PTFE: Uses and Applications

First and foremost, the conformable plastic finds itself die-cut into rings and seated against large flange faces. Heavy-duty bolts and nuts are tightened in special patterns so that installer-imposed compressive forces surround a seal and pipe cavity. The point being, ePTFE can endure the highest imaginable compressive energies, yet gaskets made from this flexible fluoroelastomer seal won’t crack under the pressure. Creep and blowout impervious, too, the gaskets can contain high-pressure fluid streams. Because of these features, expect to find ePTFE gaskets used in the kind of applications that employ continual thermal cycling. In oil refineries and chemical processing plants, in cryogenics facilities and heat exchanger usage areas, the seals cope with high-to-low temperature transients. Low-to-high thermal variances are similarly tolerated.

If that last sentence doesn’t quite make sense, imagine an active equipment line. Pressure vessels are storing a caustic medium in here. That substance is hot and being held at high pressure. Now, many gasket materials can tolerate one or two of those energetic threats. ePTFE can tolerate all of these threats. Even pressed down hard by two flange faces, the expanded PTFE holds firm. Better yet, though, if the system using the gaskets executes some kind of a phase change, one that changes the processing temperature or storage pressure, then the gaskets won’t suffer. Free of creep, strong and reliable, the fluoroelastomer withstands application and process transients.

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