Production processes utilising hazardous chemicals such as acids and amines, very often at elevated temperatures of 150°C or more, occur in a wide range of manufacturing industries including oil and gas, chemical, pharmaceutical and semiconductor. The combination of corrosive fluids and high temperatures can be particularly destructive for any sealing elements used in valves, pumps and other equipment forming part of a production process and associated pipework.
Interruptions to production processes through leaks and breakdowns resulting from seal failures can prove to be very costly, as well as having potential ramifications of causing environmental damage and jeopardising workforce safety.
The DuPont™ Kalrez® Spectrum™ 6380 perfluoroelastomer sealing parts are a non-black product specifically developed for chemical processes involving hot, aggressive amines. In addition, this product has an excellent overall chemical resistance and mechanical properties making it suitable for applications involving both static and dynamic sealing requirements. This cream coloured product is a prime choice for sealing operations with harsh aggressive chemicals, and it can withstand a maximum continuous service temperature of 225°C, with short-term excursions to higher temperatures also being permissible.
Digital Mass Flow Controllers (MFC’s), as typically used in the semiconductor, chemical processing, food and pharmaceutical industries, are designed to both measure and control the flow of various gases and liquids. Applications also occur where MFC’s are used in analytical laboratories for High Pressure Liquid Chromatography. In many applications the gases and fluids are operating at modest temperatures up to 80°C, but can include aggressive media flows which necessitate the use of specialised chemical-resistant elastomer seals.
Most gas flow meters are equipped with seals made of DuPont™ Viton® fluoroelastomer. However MFC’s need O-ring seals and other custom parts that do not swell in the presence of more aggressive chemicals utilised within their wide range of industrial applications. The sealing specialist Dichtomatik Ltd, is an authorised distributor for the DuPont™ Kalrez® range of sealing products, designed to give extended performance when operating with the widest range of chemicals, even incorporating elevated temperature conditions. Tests undertaken with an MFC, fitted with DuPont™ Kalrez® Spectrum™ 6375 O-rings and custom parts, increased reliability of operation and the overall Meantime Between Failures (MTBF) of the equipment.
Dimethyl ether (DME) burns much cleaner than diesel oils, and is also proving to be an economic and effective alternative fuel or fuel additive for use with gas turbines as well as petrol and diesel powered engines. However, the seals used on diesel engine injector tips must be specified to resist degradation where an aggressive alternative fuel such as DME is being used. Several elastomers and even fluoroelastomers (FKM’s) have been evaluated for use with DME powered engines, but operating temperatures above 100°C have led to seal degradation resulting in reduced engine performance and reliability.
However, the operation of diesel engines powered by DME fuel for commercial passenger transportation, with DuPont™ Kalrez® 6375 O-ring seals fitted to the fuel injectors, has achieved and maintained reliable engine performance without premature seal degradation. The broad chemical resistance of the Kalrez® parts, coupled with their high temperature compatibility enabled a significant improvement in engine performance as well as considerably extending useful operating life.
The Dupont™ Kalrez® Spectrum™ 6380 is a non-black sealing product that has been specifically developed for chemical processing applications involving hot and aggressive amines. Amine plants are operated throughout the world, typically in oil refineries and gas plants for the removal of H2S (hydrogen sulphide) from a product stream such as natural gas. New sources of oil and natural gas fields in the Middle East can incorporate up to 30% of H2S which is known as ‘sour gas’. However, the new, stricter environmental standards require ever decreasing contents of H2S, and the process of removing this contaminant from natural gas is commonly referred to as sweetening.
H2S is highly toxic and needs to be handled with care as it can cause embrittlement in metal equipment. Together with the harsh chemical environments and high temperatures that amine processes operate under, destructive swelling can occur with conventional elastomeric sealing components including fluoroelastomers (FKM) and perfluoroelastomers (FFKM). Loss of mechanical properties and extrusion of O-ring seals can result, leading to leakage and increased valve operating torques where seal face deformation has also occurred.
We understand that you may need assistance, and/or extra information on troubleshooting for O-rings and seals, and Dupont have kindly supplied this selection of guides below.
These troubleshooting sections from Dupont, include photos of O-rings and seals damaged from chemical, thermal, or mechanical attack. By understanding the cause of O-ring failure, proper selection of an alternative elastomer or seal design can help improve seal life.
For help in evaluating your sealing performance, DuPont also offer assistance in compound selection and seal design for Kalrez® parts. Before an in-depth analysis of O-ring failure can be provided, application data, such as process chemicals, temperatures, etc. must be supplied.
Please click on the links to see the guides:
Reliability engineering for harsh oil and gas drilling environments such as deep water and shale has just taken a major step forward with the advent of DuPont™ Kalrez® 0090 perfluoroelastomer O-rings. In rigorous third-party testing for rapid gas decompression (RGD) resistance per the NORSOK M-710 Rev 2 standard, Kalrez® 0090 O-rings received the best possible rating of 0000. The tests were conducted by the independent Materials Engineering Research Laboratory Ltd. (MERL) in the U.K. In contrast to Kalrez® 0090 parts, other competitive seals can pass the minimum requirements of NORSOK M-710 with multiple internal cracks developed during test cycling.
DuPont Performance Polymers Introduces Zalak® 5300 Seals for Cost-Effective Sealing in Photovoltaic Crystalline Silicon and Thin Film Manufacturing.
DuPont Performance Polymers (DuPont) will introduce DuPontTM Zalak® 5300 high-performance seals for photovoltaic cell manufacturing at Intersolar Booth 8159 in San Francisco, July 13-15. Zalak® 5300 seals bridge the performance gap between standard fluoroelastomers (FKM) and perfluoroelastomers (FFKM) seals. Zalak® 5300 seals are specially formulated for use in plasma environments, such as edge isolation, ARC coating in crystalline cell manufacturing, TCO sputtering deposition, and selective a-Si PECVD applications in PV cell manufacturing.
Kalrez 0090 perfluoroelastomer O-ring seal products from DuPont Performance Polymers are now available from the UK sealing specialists Dichtomatik Ltd. These products have been developed by DuPont to provide outstanding resistance to rapid gas decompression (RGD) combined with broad chemical resistance, as experienced in the harsh environments of the oil and gas industries. As an official authorised distributor of DuPont Kalrez products, Dichtomatik provide a first class service and can also offer full technical support for customers experiencing sealing problems involving extreme temperature or pressure conditions combined with aggressive fluids.
The Dupont™ Kalrez® Spectrum™ 6380 is a non-black sealing product, that has been specifically developed for chemical processing applications involving hot and aggressive amines. Amine plants are operated throughout the world, typically in oil refineries and gas plants for the removal of H2S (hydrogen sulphide) from a product stream such as natural gas. New sources of oil and natural gas fields in the Middle East can incorporate up to 30% of H2S which is known as ‘sour gas’. However, the new, stricter environmental standards require ever decreasing contents of H2S, and the process of removing this contaminant from natural gas is commonly referred to as sweetening.
Freeze-drying processes can involve cycling temperatures in the range of -20°C to +130°C, together with solvents and/or water under medium/high pressures. This combination of aggressive working conditions is conducive to the development of thermal stresses in the seals utilised for the freezer operation. These thermal stresses can also result in associated mechanical stresses leading to premature sealing failures due to cracking and blistering of the seal materials. Dupont™ Kalrez® 6230 perfluoroelastomer (FFKM) parts have been developed to meet such challenging sealing requirements, offering excellent steam cycling resistance up to 260°C.