Seals and Gaskets

Seals, O-rings and Gaskets For Demanding Applications

Parts made with high-performance DuPont elastomers help engines and heavy equipment run longer, safer, cleaner and more efficiently.

Specialized, high-performance seals, O-rings and gaskets made from DuPont elastomers provide durable solutions for high heat and aggressive chemical uses.

They’re designed to help maintain performance, to help manufacturers comply with stricter standards and specifications, and to help reduce emissions and risk of unexpected downtime.

Meeting Key Challenges

In the automotive industry, increasingly stringent emissions regulations, the increase in manufacturer warranty times and the elevation in engine temperatures re-set the checklist for material properties.

For aerospace seals, the latest engine and equipment designs have prompted the need for more exacting solutions that combine high resistance with custom fit.

For the chemical processing industry, the focus is on improving uptime performance by reducing seal failures.

A Portfolio of Choices

From both a cost and longevity perspective, the broad DuPont elastomer portfolio provides customers more ways to collaborate to meet changing technology, regulatory and marketplace demands.

Let’s take a look at a few of these proven performers.

  • Kalrez® perfluoroelastomer parts are used for extreme chemical and temperature demands in the chemical process and aerospace industries.
  • Viton® fluoroelastomer polymers are used in the chemical process industry (CPI) because they an economical solution in high-temperature and harsh-chemical environments.
  • Viton® is selected for use in automotive fuel systems, due to its low emission advantages as result of low permeation of many fuel types.
  • Viton® is also used where exposure to engine oils, automatic transmission fluids (ATF) and greases at high temperatures is required.
  • Vamac® ethylene acrylic elastomer is the elastomer of choice for automotive applications, such as automatic transmissions, as a result of excellent performance in automatic transmission fluids (ATF) and engine seals, such as rocker cover gaskets and oil pan gaskets.
  • Neoprene polychloroprene has been used in sealing applications since the 1930s for its many advantages over natural rubber, including resistance to heat, weather, ozone, flame, oil, hydrocarbon fluids, and a broad range of other chemicals.

A Proven Performer Spreads its Wings

DuPont™ Kalrez® perfluoroelastomer parts are engineered to stand up against jet fuel, engine lubrication oils, hydraulic fluids, rocket propellants and oxidizers, all in the presence of extreme temperatures. The exceptional performance of Kalrez® parts are proven in applications, including mechanical seals in the chemical process industry, aviation, marine and gas turbines, auxiliary power units, hydraulic actuators and bleed air valves and fittings. Kalrez® perfluoroelastomer parts are manufactured and are sold by DuPont and its authorized distributors.

Kalrez® AeroSeal™ 7777 and 7797, developed for outstanding thermal stability at 325°C (617°F) and excellent compression set resistance, have been selected for use in jet engines. Both have superior High Thermo-oxidative Stability (HTS).

The latest product Kalrez® 7800 resists corrosion with titanium, and is manufactured in accordance with AMS7257D.

Matching Resistance to Chemical Processes

DuPont™ Viton® fluoroelastomers are the standard for broad chemical resistance for applications up to 230°C, The Viton® family consists of many polymer grades with varying levels of fluorine content and cure chemistries, permitting a balance of chemical resistance and mechanical properties to be selected to match the application.

DuPont™ Viton® is the elastomer of choice in mechanical seals and associated applications in the chemical process industry, due to its great chemical resistance, high temperature capabilities, polymer traceability and associated technical services provided by DuPont.

Driving Seals to New Standards

As fuel emission regulations continue to escalate industry challenges, DuPont™ Viton® fluoroelastomers have been selected for their effectiveness in underhood applications, helping carmakers meet their near-zero fuel permeation targets.

Viton® performs well in gasoline-alcohol blends, which are generally more aggressive than standard gasoline types. Viton® also provides excellent performance in biodiesel fuels. This helps design engineers make informed material choices for fuel system seals, O-rings and gaskets, which are critical parameters needed for meeting stringent emission regulations.

Bonding with Cost-Effective Performance

DuPont™ Vamac® ethylene acrylic elastomer provides resistance to mineral-based oils and synthetic engine oils at operating temperatures ranging from -40ºC (-40ºF) to 150º+ C (302ºF). Vamac® also provides excellent performance in the newest and most aggressive automatic transmission fluids (ATF).

Examples of Vamac® applications include:

  • Transmission lip seals – hot, cold, pressure, good process ability for seal dimensions and fit
  • Cam cover gaskets – low melt viscosity for molding and overmolding long sections; excellent swell resistance to keep thickness of gasket stable, eliminating leakage and oil weep.
  • Bonded Piston Seals — high-temperature durability and resistance to automotive service lubricants.

Versatile, Cost-Effective Solutions

Neoprene polychloroprene has been used sealing applications since the 1930s for its many advantages over natural rubber, including resistance to heat, weather, ozone, flame, oil, hydrocarbon fluids, and a broad range of other chemicals. It’s also exceptionally tough and resists cracking and abrasion, for applications such as belting and jacketing. Neoprene remains a tested, cost-effective choice for many sealing, mechanical and industrial applications, due to:

  • Outstanding physical toughness.
  • Excellent resistance to damage caused by flexing and twisting.
  • Resistance to degradation from sun, ozone, and weather.
  • Great performance in contact with oils and many chemicals.
  • Maintains physical properties over a wide temperature range

Highway and bridge seals have been manufactured with Neoprene for over 50 years. Window seals can be produced for maintenance-free applications in the most challenging designs and environments.


Information & Ideas

*The Viton® fluoroelastomer business is now part of The Chemours Company.  Visit for more information.


*For information on Neoprene, contact