Tag Archives: Kalrez

Kalrez® 7375 Offers Outstanding Properties & Performance

Kalrez 7375 offers broad chemical and water/steam resistance

The newer compound from 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?

Three ways that Kalrez 7375 would be a suitable upgrade or compatible compound for your application:

1. Kalrez® 1050LF is a classic grade and longtime favorite for premium performance. 1050LF end-users will likely see a performance boost if they switched to 7375, especially if used in steam or hot water applications.

2. If using Kalrez® 4079 or Kalrez® 7075 and broad chemical resistance is essential (including water/steam), 7375 could be a superior compatibility match resulting in enhanced longevity. 7075 offers the highest thermal capability but cannot support 7375’s chemical compatibility with steam. See table below:

Volume Change between different FFKMs after 672 hours of chemical immersion.

3. If lifetime issues or seeking to extend time between repairs are concerns when using Kalrez® 6375, end-users would most likely see a significant impact with 7375. However, transitioning to 7375 is not necessary if 6375 is executing up to standards.

Kalrez 7375 Benefits

  • Superior thermal stability of 572 °F (300 °C)
  • Excellent broad chemical resistance
  • Outstanding steam and water resistance
  • Available in most O-ring sizes: AS568, Metric, JIS (custom shapes upon request)
  • Combination of Kalrez® quality and Gallagher Fluid Seals’ customer service
picture of kalrez compression graph
Kalrez 7375 demonstrates excellent long-term compression set in hot air at 500 degrees Fahrenheit.

Product Description

DuPont™ Kalrez 7375 perfluoroelastomer parts are an innovative FFKM product based on a patented crosslinking system for chemical process industry applications where broad chemical and water/steam resistance are needed at elevated temperatures. Kalrez 7375 parts exhibit excellent compression set resistance, outstanding physical property retention, and good mechanical strength properties. A maximum application temperature of 300 °C is suggested.


The original article was featured on Dichtomatik’s website and can be found here.

Gallagher Fluid Seals is an authorized distributor of Kalrez products. For information about selecting the correct compound for your specific application, contact our engineering department.

Switching from PTFE to Kalrez® O-Rings Increase Life by 6,000%

The Seal Challenge

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 8 hours operation.

The cost to Dow AgroSciences in extra performance time and maintenance had become unacceptable, and the company sought a much more resilient sealing material that would better withstand frequent cleaning and product changes.

picture of kalrez as ptfe replacement

The Kalrez® Spectrum™ 6375 Solution

Dow Agro Sciences S.A. installed Kalrez 6375 perfluoroelastomer O-rings to replace the PTFE seals, with dramatic and immediate improvement.

They managed to extend the lifetime of dynamic and static seals fitted to their product filling line from one day to an average of two months, an improvement of some 6000%.

Also the seals of FEP/FKM, fitted to the piston rod of a Type SRC Alfa Laval valve, were replaced by Kalrez perfluoroelastomer parts. Operating lifetime has increased from 8 hours to between 8–12 months!

Kalrez 6375 parts are designed specifically for the chemical process industry. They provide outstanding performance in an extremely wide range of chemicals including acids, bases, amines and steam. The innovative patented curing system allows for continuous upper service temperatures of up to 275 °C in applications such as mechanical seals, valves, flanges and pumps where elastomeric sealing is critical.

In addition, Kalrez is a thermoset perfluoroelastomer part and offers excellent elastic properties and resistance to mechanical damage, unlike PTFE which is a thermoplastic and appears to lack the necessary resilience to withstand mechanical shock in a process application such as this.

Key Advantages of Kalrez 6375

Since switching to custom Kalrez 6375 O-rings Dow AgroSciences S.A. reports an average seal lifetime of two months. That’s an increase of approximately 6,000% over the previously fitted PTFE seals.

The operating lifetime of the seals fitted to the piston rod of a Type SRC Alfa Laval valve increased from 8 hours to between 8–12 months.

Switching to Kalrez® Spectrum™ 6375 parts allowed Dow AgroSciences to increase the operating uptime of their filling machines and to improve overall reliability of their packing line. They have also significantly reduced the time spent in O-ring replacement. The Mechanical Maintenance Manager also reported cost savings as a result of major improvements in safety and reliability, and in reduced maintenance.


Gallagher Fluid Seals is a preferred distributor of Dupont Kalrez® products. For more information or to speak with an engineer, visit Gallagher Fluid Seals or call 1-800-822-4063.

Kalrez 7375® for High Temp Resistance

Kalrez® 7375DuPont™ 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.

Continue reading Kalrez 7375® for High Temp Resistance

Kalrez® Parts Extend Service Life for Process Instrument

The Challenge

By switching from gasket seals of PTFE to custom gaskets of DuPont™ Kalrez® perfluoroelastomer parts in the sensor head of a process instrument refractometer used by the food, pulp and paper and chemical industries, process instrument manufacturer K-Patents Oy, Vantaa, Finland, was able to dramatically extend instrument service life, increase reliability and safety, and reduce costs for the company and its customers.

Instrument - Refractometer
Delicate digital detector circuits and fibre optics in the sensor head of K-Patents’“PR-01-S” process refractometer are sealed from attack by aggressive process media, temperatures from –20 ° to +220 °C, and pressures from –0,7 to +25 bar, by two DuPont™ Kalrez® gaskets situated either side of the vital Spinel prism

The Solution

Aggressive environment
Through permanent in-line fluids immersion, K-Patents’ “PR-01-S” refractometer is exposed to temperatures      from –20 ° to +220 °C, pressures from –0,7 to +25 bar, and some 500 process fluids and chemicals, many of which are extremely aggressive. Delicate digital detector circuits and fiber optics in the sensor head are sealed by two gaskets from attack by aggressive fluids. Because of inherent inelasticity, the original PTFE gaskets could not withstand the dynamic temperature fluctuations of many food, pulp and paper and chemical manufacturing processes, creating a leak path allowing process media to enter and damage the device. As a result, costly replacement of the PTFE seal became necessary approximately every 6–12 months.

Continue reading Kalrez® Parts Extend Service Life for Process Instrument

[VIDEO] How to Choose a Fluoroelastomer

Fluoroelastomer Basics - Consideration When Choosing a FluoroelastomerGallagher Fluid Seals recently posted our new Fluoroelastomer Basics webinar on gallagherseals.com.  This is the third and final section of our webinar, focusing on Considerations When Choosing a Fluoroelastomer. The full video is now available on our Resources page.

This video discusses considerations when choosing a fluoroelastomer, including temperature performance range, performance in harsh chemical exposure, and the need to take caution when using fluoroelastomer blends.

[VIDEO] Fluoroelastomer Materials

Gallagher Fluid Seals recently posted our new Fluoroelastomer Basics webinar on gallagherseals.com.  This is the second section of our webinar, focusing on Fluoroelastomer Materials. The full video is now available on our Resources page.

This section of the video discusses different fluoroelastomer materials, along with their mechanical and physical properties, and in which applications they’re normally found.

Pharmaceutical Seals for CIP and SIP

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.

Pharmaceutical Seals for CIP and SIP

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.

Continue reading Pharmaceutical Seals for CIP and SIP

Kalrez® Seals for Semiconductor Processing

Purity is critical to high wafer yield, and Kalrez® seals are designed with properties that help reduce contamination from particulates, outgassing and extractables.

Semiconductor Processing Seals

Kalrez® Seals - Semiconductor ProcessingKalrez® seals for semiconductor processing are field-proven in the manufacture of semiconductor chips.

They can help extend planned maintenance intervals, and thereby lower long-term cost of ownership, in a wide range of semiconductor processes. In a number of fabrication customer evaluations, Kalrez®seals exhibited improved mechanical strength, lower particle generation and longer seal life versus competitive perfluoroelastomers, in both static and dynamic sealing applications.

Operational Improvements

Kalrez® seals can help improve semiconductor manufacturing in a range of wafer-fabricating operations, including:

  • Deposition
  • Etch
  • Ash/strip
  • Thermal
  • Wet

Continue reading Kalrez® Seals for Semiconductor Processing

New Perfluoroelastomer Withstands Aggressive Chemical Environments

Kalrez Spectrum 7275DuPont 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.

Continue reading New Perfluoroelastomer Withstands Aggressive Chemical Environments

Elastomer or Plastic… Which Should You Choose?

Kalrez KLX-16011Gallagher Fluid Seals is a longtime partner of DuPont®’s, having specified thousands of DuPont perfluoroelastomer parts over the past few decades.

While elastomers were originally created as an alternative to natural rubber, they have expanded to include materials such as high-performance perfluoroelastomers for demanding applications.

These materials can also be used in place of plastics in most, if not all, applications. DuPont is at the forefront of perfluoroelastomer development, creating elastomers with properties that can help meet highly specific application requirements.

Read on to learn more from Dupont about the differences between elastomers and plastics, and how elastomeric seals perform compared to plastic seals.

Continue reading Elastomer or Plastic… Which Should You Choose?