Sealing technology manual for the process industry

Applications • Beverage industry: • Use of EPDM materials • Thermal resistance in steam and sterilization to +140 °C (+284 °F), for brief periods up to +160 °C (+320 °F) • Suitable for aqueous media and cleaning processes • For applications involving nitric or formic acid, high tem- peratures and media concentrations, EPDM represents the most economical solution in comparison to other ma- terials. In extreme cases, however, EPDM is not optimal either and alternatives may have to be used • Dairy industry: • EPDM, FKM, VMQ or HNBR materials are used, depending on the fat content and temperature • In certain cleaning media, HNBR, FKM and VMQ cannot match the service life of EPDM; however, unlike EPDM they are resistant to fats, thus making them well-suited for use at high temperatures and concentrations • Pharmaceutical and chemical industry: • EPDM, FKM, VMQ or HNBR materials are used, depending on the production media and solvents • FKM isresistanttocertainoilsandsomearomaticoils,but shows limited resistance to alkaline cleaning media. It is also more prone to swelling in acids, making it necessary to select compatible cleaning media when using FKM • Certain applications in the production of flavorings, in pharmaceutical and chemical processes exceed the resist- ance properties of EPDM, VMQ, and HNBR. In such cases, Freudenberg recommends the use of Fluoroprene® XP materials THE ADVANTAGES AT A GLANCE • Patented torque-reducing design allows high-frequency operating cycles with low actuating forces and minimal abrasion • Extremely easy to assemble • Leak-free and dead space-free variants available • Low-friction coatings available • A broad range of material versions for high media and temperature resistance DESIGN NOTES Dimensions • Information on the minimum and maximum dimensions of the flanges and valves are necessary for gasket design • Minimum necessary and maximum permissible actuating forces should be included in design consi- derations • Use of a patented Freudenberg design to reduce torque Tolerances Lowest possible tolerances with regard to the seal and installation space Surfaces • Perfectly smooth (no gaps or seams) in the dynamic area • The sealing butterfly should be polished on the sealing surface (Rmax 2.5 µm, Ra 0.05 – 0.3 µm) • The shaft should be polished in the sealing area (Rmax 2.5 µm, Ra 0.05 – 0.3 µm) APPENDIX PRODUCT PORTFOLIO MATERIALS RESISTANCE & PURITY ENGINEERING PLASTICS ELASTOMERIC MATERIALS TECHNICAL FUNDAMENTALS INTRODUCTION 85

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