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:
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
Oil and gas production and chemical manufacturing industries present sealing technologies with some of the harshest and most demanding operating environments.
"We screen Kalrez against some of the most aggressive corrosive fluids," says Dr Christopher Bish, Technical Fellow. "And in addition to the fluid testing, we did some compression set testing and stress relaxation testing at high temperatures. We now have one of the most chemically resistant and thermally stable compounds possible."
We screen Kalrez against some of the most aggressive corrosive fluids
One of the things that sets Dupont Kalrez apart is their quality control system, which gives them the ability to track materials as they flow through the plant. Scanning the barcode on the
Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.
Original content can be found on Parker’s Website and was written by Nathaniel Reis, Applications Engineer for Parker O-Ring & Engineered Seals Division.
In our semiconductor entry from last month, we noted that lowering the cost of ownership is a multi-faceted goal. We discussed how one of the areas for potential improvement
In chemistry, strong oxidizers are substances (like chromic acid) that can cause other substances (like seals and gaskets) to lose electrons. So, an oxidizer is a chemical species that undergoes a reaction that removes one or more electrons from another atom.
This causes a change in mass. Metals will turn into their respective heavier oxides, and the carbon in graphite will oxidize into carbon dioxide—which, although molecularly heavier, is a gas at room temperature.
This happens in pumps, valves, pipelines or any other equipment that have seals and gaskets carrying a strong oxidizer. It will cause pitting or rust and, depending on your choice of seal material, may require shorter service intervals. Ultimately, you may have to look for a more suitable material that can handle strong oxidizers.
More importantly, an oxidizing agent can cause or contribute to
Gallagher recently released our High Performance Elastomer Seals for the Instrumentation Industry White Paper. This was written by Russ Schnell, an Elastomer Consultant contracted by Gallagher Fluid Seals, and a former Senior Application Engineer with the Kalrez® perfluoroelastomer parts business at DuPont. This white paper is now available for download on our Resources page.
Below is the third and final section of the white paper, which will discuss the importance of proper seal and groove design.
Proper seal design is a necessity for elastomer seals to perform reliably over the long term. Many of the instrument applications mentioned above use o-ring seals. The suggested compression for an elastomer o-ring seal to perform properly is typically a minimum of 16%, and a maximum of 30%. However, this range must also take into account the thermal expansion of an elastomer at elevated temperatures as well as any swell due to chemical exposure. Many of the elastomer seals used in instruments are small o-rings, which can create design issues. This is especially true for perfluoroelastomer parts which have a relatively high coefficient of thermal expansion (CTE). Fluoroelastomers have a lower CTE, making seal design easier at elevated temperatures.
Gallagher recently released our High Performance Elastomer Seals for the Instrumentation Industry White Paper. This was written by Russ Schnell, an Elastomer Consultant contracted by Gallagher Fluid Seals, and a former Senior Application Engineer with the Kalrez® perfluoroelastomer parts business at DuPont. This white paper is now available for download on our Resources page.
Below is the second section of the white paper, diving into applications where the measurement is made in analytical laboratories which employ numerous solvents in a wide range of analyses and test equipment.
The final set of instrumentation is laboratory test equipment. As opposed to the laboratories in chemical plants, which often perform the same routine analyses on plant process streams, general analytical labs employ numerous solvents in a wide range of analyses and test equipment. As such, the ability of seals to resist a breadth of chemicals without degradation or leaching contaminants into a sample is of great importance. Although instrument seals are easily replaced in a laboratory environment, this operation still takes a technician time. It is always easier if the system can be flushed with a cleaning solvent and then be ready to run the next sample versus having to change out an elastomer seal due to incompatibility with a solvent.
FFKMs, also known as perfluoroelastomers, were first developed in the 1960s for applications involving high temperatures and/or aggressive chemicals. Perfluoroelastomers exhibit many properties similar to PTFE (polytetrafluoroethlyene, or Teflon®), and are considered inert in almost all solvents. However, PTFE is a plastic, and when compressed, it will not recover to its original shape. On the other hand, elastomers contain crosslinks, which act as springs to give the material resiliency and the ability to recover after a part has been compressed - this resistance to permanent compression gives the material the ability to maintain a seal over time. (To learn more about perfluoroelastomers, download our Introduction to Perfluoroelastomers White Paper).
The article below was recently published on FlowControlNetwork.com, and discusses how FFKMs are being used in oil & gas exploration, as production companies are increasingly operating in high-pressure, high-temperature (HPHT) downhole conditions.
Improving technologies and methods to increase the recovery of oil from existing reservoirs is a global challenge. In the U.S., oil production at reservoirs can include three phases: primary, secondary and tertiary (or enhanced) recovery. The U.S. Department of Energy (DOE) estimates that primary recovery methods — which rely on the natural pressure of the reservoir or gravity to drive oil into the wellbore, combined with pumps to bring the oil to the surface — typically tap only 10 percent of a reservoir’s oil. Furthermore, secondary efforts to extend a field’s productive life — generally by injecting water or gas to displace oil and drive it to a production wellbore — still only push recovery totals to between 20 and 40 percent of the original oil in place. Clearly, much untapped oil and gas remains in existing wells.