Perfluoroelastomers (FFKM) These are best known as Kalrez®, although other grades do exist. The compounds contain fully fluorinated polymer chains and hence offer the ultimate performance of elastomers when considering heat and chemical resistance.
Chemical properties Excellent resistance to fuels, all types of lubricating oils and greases, mineral-based and fire resistent hydraulic fluids, solvents, alcohols, most acids and alkalis.
Typical operating temperatures -25°C to +315°C continuous, or +350°C intermittent.
Fluid sealing duties Various Kalrez® grades are recommended for critical and/or high purity sealing applications in industry sectors such as pharmaceutical and food processing, semiconductor fabrication, oil and gas, chemical and petrochemical processing, and defence and aerospace. However, it should be noted that the moderate mechanical properties of perfluoroelastomers tend to deteriorate rapidly at elevated temperatures.
James Walker supplied grades We are the authorised UK distributor for the design, supply and technical support of sealing and fluid handling parts made by DuPont Performance Elastomers from its many grades of Kalrez®.
Click here to download full 'O' Rings Guide pdf (1.37MB).
Perfluoroelastomers (FFKM)
