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Beware of Fluoroelastomer (FKM) Imposters

The world’s first fluoroelastomer was Viton, well known for its excellent resistance to heat, aggressive fuels and chemicals. It has worldwide registration Du Pont to ISO 9000 and ISO/TS 16949.

There is no such thing as a low cost fluoroelastomer, that will perform as a sealing material in the same way as parts made with 100% Viton would. When you purchase blends of FKM, what you are getting are essentially very expensive versions of hydrocarbon rubbers and not a low cost fluoroelastomer. FKM cannot be blended without significantly degrading its resistance to heat, aggressive fuels and compression set.

In the Nuclear, Semiconductor, Vacuum, Analytical and Pharmaceutical industries, where degassed seals are required, it is essential to specify genuine 100% Viton. Many substitute FKM materials cannot withstand the temperature, for the period of time required to undergo the degassing process.

Du Pont Dow Performance Elastomers have developed many types of Viton to meet specific end-use and processing needs, varying in chemical resistance and mechanical properties. Whether the application is automotive, chemical processing or any other industrial application, there is a specific type of Viton that best meets the performance requirements. The general purpose types differ primarily from the specialty types in chemical resistance.

In the specialty family there are four types that are tailored for superior fluid resistance, low temperature or a combination of these properties.
Standard and Specialty

Types of Viton                Applications
A,AL,GAL-S,GLT-S            General purpose sealing: Automotive, Aerospace fuels & lubricants
B, BL, GBL-S, GBLT-S      Chemical processing, power, utilities, seals & gaskets
F, GF-S, GFLT-S                Oxygenated automotive fuels, concentrated aqueous inorganic acids, water and steam
TBR-S                               Automotive & Off-Road (High pH requirements)
ETP-S                               Oil Exploration/Production
                                         Special sealing requirements for harsh Environments.

For more detailed Technical Information we would recommend you visit the website of Du Pont Dow Performance Elastomers.
When it matters, always insist that parts are made with 100% Genuine Viton, and not an FKM substitute.
Viton is the registered trademark of Du Pont Dow Performance Elastomers.
For more detailed and extensive guidelines we recommend the BSI website, and to purchase a copy of The International Standards BS ISO 2230-2002.


The company is registered to ISO 9001-2015, our certificate is available to download. In addition, the company operates its own Quality Policy and a programme of "Continuous Improvement" The company is also a Member of the British Standards Institute, our certificate of membership is available to download


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