May 16th, 2016 by WebSeal Inc
Designing sealing protection for harsh environments remains a continuing challenge in many industries. One of the best solutions for long-term efficiency and reliability is the use of fluorocarbon elastomers (FKMs).
FKM polymer is the generic reference for fluoroelastomers in ASTM D1418. Initially developed over half a century ago, this synthetic rubber offers outstanding resistance to chemicals, oils, fuels, and temperature extremes, as well as superior performance in other critical areas. According to the International Institute of Synthetic Rubber Producers, today’s FKM polymers have a much broader fluids resistance profile than standard fluoroelastomers. In addition, they are able to withstand strong bases and ketones as well as aromatic hydrocarbons, oils, acids, and steam.
Examples of end-use in industrial, oil and gas, aerospace & defense, automotive, and other manufacturing applications include:
- Electrical connectors
- Expansion joints
- Fuel systems
- Hydraulics systems
- Jet engines and manifolds
- Lubrication systems
- Valve liners and stems
Current categories of fluoroelastomers are based on chemical makeup and structure as well as the amount of fluorine added, to meet specific needs in differing environments. Web Seal can provide engineered gaskets, O-rings and molded shapes made from a wide variety of FKM fluoroelastomers, including DuPont’s Viton®.
To help you find the best FKM for your use, be specific in defining your requirements:
What is your chemical media exposure?
Chemical Resistance: Fluoroelastomers perform reliably under severe chemical where many other seal materials cannot survive, especially when in contact with petroleum fuels and many solvents. FKM formulations are tailored for:
- Mineral-based oils, acids, grease and hydraulic fluids
- Aliphatic hydrocarbons (butane, propane, natural gas)
- Chlorinated hydrocarbons (trichloroethylene, carbon tetrachloride)
- Gasoline, including resistance to rapid gas decompression
- Steam and hot water (in customized compounds)
What are the temperature ranges of your environment?
FKMs have been developed to meet a wide range of extreme temperatures.
Heat Resistance: FKMs have excellent resistance to high temperatures, up to 204ºC/400ºF.
Cold Flexibility: Fluorocarbon components can create effective seals at temperatures as low as -26ºC/-15ºF.
What mechanical stresses are involved?
FKMs are available for static and a variety of dynamic applications, electrical properties, and hardnesses.
What is the compression load?
Fluorocarbon elastomers have superior compression set and recovery characteristics, especially important in critical areas such as risk to life or danger of environmental damage.
What other issues are important for seal design in your overall application?
- Flame Retardance
- Gas Permeability
- Use in a Vacuum
- Weathering and Ozone Resistance
- Installation Process
- Steam or Hot Water
While FKM fluorocarbon elastomers is a more expensive option, their use may actually save significantly on downtime and replacements, offering a savings of labor, parts and productivity costs over the life of the product.
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