The filling line at Dow AgroSciences plant in Drusenheim, France - a global leader in pest management and biotechnology products - processes aggressive solvents, surfactants and concentrated herbicides at temperatures ranging from 10 to 45 °C, and pressures from 1.5 to 3.5 bars Eff. Filling machine valves on the line were fitted with dynamic PTFE O-rings, while the machine hoses were equipped with static O-rings, also of PTFE.
Each time the mechanical maintenance team performed a clean-in-place procedure at 80 °C, or made a product change on the filler, the PTFE seals became mechanically damaged. This meant they had to change the PTFE O-rings on a daily basis, since seal lifetime never extended beyond 24 hours before replacement.
In a different application at the same plant, seals of FEP/FKM, fitted to the piston rod of a Type SRC Alfa Laval valve, failed regularly after only
It's known that DuPont™ Kalrez 0040 and Kalrez 0090 are two of the most popular low temperature perfluoroelastomers in the marketplace.
Each compound has unique physical properties and can be better in certain applications. In fact, GFS engineers are often asked for compound guidance for these low temperature FFKMs.
This video discusses, at a very high level, the similarities and differences between Kalrez 0040 and Kalrez 0090.
DuPont™ Kalrez® 7375, is an innovative FFKM oil-seal product exhibiting broad chemical and water/steam resistance properties required at high temperatures in chemical process industry applications. Kalrez 7375 parts present excellent compression set resistance, exceptional physical property retention, and improved mechanical strength properties.
Other Kalrez compounds have done the job over the years when faced with many of these sealing challenges, but how does it compare to this new compound?
DuPont™ Kalrez® 8575 perfluoroelastomer parts are a white product for “select” etching, ashing/stripping and deposition process applications. It offers low weight loss in Oxygen and Fluorine-Based Plasmas, low outgassing and excellent elastic recovery properties. Kalrez® 8575 has excellent vacuum and long-term sealing performance, good mechanical properties and is well-suited for both static and dynamic sealing applications (e.g., gas inlets, chamber lid seals, slit valve door seals, etc.). A maximum continuous service temperature of 300°C (572°F) is suggested. Ultrapure Post-Cleaning and Packaging is standard for all parts made from Kalrez® 8575.
PERFORMANCE
Perfluoroelastomers (FFKMs) Dupont Kalrez® are used as seals on wafer processing equipment due to their extraordinary resistance to chemicals, including reactive plasmas and extreme heat as high as 620°F (327°C). FFKM performance can vary depending upon the chemical composition. Specially formulated Kalrez products may be required to help reduce wafer contamination.
Amine treatment is a process typically used for Hydrogen Sulfide removal from natural gas (sour gas). This operation is commonly referred to as gas “sweetening," acid gas removal, or amine scrubbing
Amine units are used all over the world in oil refineries and gas plants to remove hydrogen sulfide (H2S) from a product stream. New environmental standards are more strict and require ever-decreasing contents of H2S in clean natural gas. Most of the new sources of oil and gas discovered today have high contents of H2S which demand more efficient removal technologies (the Shah Gas field in the United Arab Emirates for example has up to 30% H2S).
Amine units operate under harsh chemical environments. H
Kalrez Spectrum 7275 is a perfluoroelastomer that provides long life sealing in an array of aggressive chemical environments that typically make sealing difficult: ethylene oxide, acrylic monomers, silanes and chlorosilanes, and strong oxidizers such as nitric acid, chlorine and chlorine dioxide.
It has demonstrated improved chemical and compression set resistance and mechanical property retention when compared to competitor’s elastomers.
Kalrez Spectrum 7275 is based on a proprietary cross-linking system, and is uniquely identified by its light brown shade.
Targeted applications include industries that depend on mechanical seals, pumps, valves, compressors, filtration columns and analytical equipment for their critical processes.
Chlorine dioxide is a strong oxidizing gas that finds many uses as bleaching agent
To meet growing demand in solar cells, the Siemens* process is used to produce highly purified polycrystalline silicon by thermally decomposing tri-chloro-silane (TCS). The reactors employed require three kinds of high-performance seals in the following locations: A) bell jar seals; B) electrode seals between the electrode and ceramic inlet; and C) a gasket for the view port seal (see schematic).
The process involves a very hot, dry environment with temperatures up to 1200°C (2100°F). Sealing components see up to 300°C (572°F). Process media include TCS and aggressive by-products of its decomposition, such as HCl gas. Superior compression set performance is needed for effective sealing and extended seal life. Very low outgassing is a key requirement for preventing contamination of the process environment.
The presence of harsh chemicals in high temperature conditions often require an upgrade from standard sealing materials to PTFE or fluoroelastomers (FKM) to improve thermal stability and chemical resistance. However, PTFE can deform and creep “hot flow” in the bell jar seal increasing the risk of product loss. FKM, with its high temperature rating of 200°C (392°F), also has deficiencies in this 300°C (572°F) environment.
Kalrez PV8070 perfluoroelastomer parts installed as washers and gaskets in reactors for the Siemens CVD process have demonstrated outstanding performance in this demanding application. Kalrez® PV8070 parts are effective seals that provide:
Bonded door seals for gate valves and slit valve door seal applications provide improved sealing performance versus conventional O-rings by reducing particle generation, extending seal life, and minimizing replacement time during preventive maintenance.
DuPont™ Kalrez® bonded door seals are designed for easy installation and low particle generation. They combine a custom seal design and proprietary adhesion technology along with the excellent plasma resistance of Kalrez® perfluoroelastomer seal materials developed for semiconductor applications. The seal is held in a “fixed” position versus conventional O-rings, thereby eliminating “rolling/twisting” and abrasion during door actuation. In addition, the seal design has been optimized using finite element analysis (FEA) to minimize
For most applications, DuPont™ Kalrez® Spectrum™ 7375 may be a suitable replacement for 1050LF.
DuPont™ Kalrez® 1050LF perfluoroelastomer parts are a carbon black-filled general-purpose product for o-rings, seals, and other parts used in chemical process industries. It is a classic-grade