Kalrez

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

High Performance Seals for Polycrystalline Silicon Process Equipment

The Challenge

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).

Application Details

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.

The Solution and Key Advantages of Kalrez PV8070

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:

Oil and gas production and chemical manufacturing industries present sealing technologies with some of the harshest and most demanding operating environments.

Harsh and Demanding Operating Environments Require Chemically Resistant and Thermally Stable Seals

"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

DuPont™ Kalrez^® 7375 FFKM sealing products provide high temperature as well as broad chemical and water/steam resistance properties. Sealing performance, reliability and safety are ensured for applications in the most demanding industrial, chemical and general industrial fields of operation.

These high performance perfluoroelastomer O-ring components are available from Gallagher Fluid Seals, the authorized distributor for a wide range of DuPont™ finished O-rings, as well as custom shapes, sheets and cord sealing components.

The Kalrez^® 7375 parts are tailored for specialized chemical applications covering broad operating temperatures from -20°C to 300°C (-4ºF to 572ºF).

These products, which incorporate patented cross-linking technology, combine both superior chemical resistance with a thermal stability which exceeds many other competitive FFKM products. They are also available in most standard O-ring sizes including AS568, metric and JIS, with custom sizes and shapes also available on request.

Clean in Place Service Benefits from Kalrez® O-rings

Hilge-Pumpen AG, Swiss subsidiary of Philipp-Hilge GmbH, Bodenheim, Germany, selected Kalrez^® 6221 perfluoroelastomer parts to seal its Euro-Hygia^®, Hygiana-HT and Contra pump series, to meet the stringent safety, cleanliness and  sterilization requirements demanded by the pharmaceutical, biotechnology and cosmetics industries.

The Challenge

Pumps used in pharmaceutical, biotechnological and sterile processes are subject to some of the highest standards and safety requirements worldwide. In addition to ease of operation they must also provide maximum biological safety without any unfavorable hydraulic characteristics that could adversely influence sensitive products.

In valve jet printing, a series of inline jets are controlled by valves.  These open and shut independently to produce streams of intermittent ink droplets.  As the product passes the printhead, these droplets create characters and/or graphics based on grid information.  

After each printing run, the printheads are washed by strong solvents or special chemicals to remove all inkjet materials from the printhead.  With such aggressive media in the process, Kalrez® is an obvious material choice.

Keep reading to learn more about Kalrez sealing valves.

DuPont Performance Materials (DPM) is a leading innovator of thermoplastics, elastomers, renewable-sources polymers, high-performance parts and shapes, as well as resins that act as adhesives, sealants, and modifiers.

Gallagher Fluid Seals is a long-time partner of DuPont™, predominantly focusing on the Kalrez® line of products which is part of DPM. The latest perfluoroelastomer offering from DPM, Kalrez® Spectrum™ 7275, offers a higher level of sealing performance in the most aggressive chemical processing and manufacturing environments.

DuPont™ Kalrez® 1045 parts were phased out of the Kalrez product line at the end of March 2016. Kalrez 1045 parts have a long history of use in dinitrogen tetroxide (nitrogen tetroxide) service.

This chemical is often used as the oxidizer in rocket propellant, when combined with a hydrazine based rocket fuel. Nitrogen tetroxide is a very strong oxidizer, and Kalrez 1045 is resistant to oxidizing liquids; it has been the product of choice for hypergolic propellant applications.