DuPont™ Vespel® Parts Enable Oliver Twinsafe® Valves to Reach New Milestone in Fugitive Emissions Control

Press Release | Feb, 23 2023
Press Release
DuPont™ Vespel® Parts Enable Oliver Twinsafe® Valves to Reach New Milestone in Fugitive Emissions Control

Stem pack achieves significant reduction in methane leaks

WILMINGTON, Del., Feb. 23, 2023 — DuPont™ Vespel® Parts and Shapes, a business within the DuPont Electronics & Industrial segment, today announced that Oliver Valves Ltd., one of the world’s leading manufacturers of Instrumentation, Piping, Subsea and Hydrogen & Carbon Capture and its sister company Oliver Twinsafe Valves, developed a stem pack using DuPont™ Vespel® SP-21 parts for the energy industry. Stem packs are used in industrial valve bodies to form a low friction, pressure-tight seal to prevent leaks. Commonly used in natural gas transfer and other demanding applications, this innovative stem pack using Vespel® advanced polyimide enables a more sustainable solution in mission-critical applications.

With methane emissions as the second-largest cause of global warming today*, immediate and major reductions in methane emissions are necessary for gas to play a supporting role in the energy transition.

The new stem pack provides a solution as purely graphite alternatives fail to meet the MESC 77/300 class B standard even at ambient temperatures, enabling considerable performance enhancements over graphite + PEEK (polyetheretherketone) ones. At 200 ºC, Vespel® allows 40 percent less leakage, while at very high temperatures (350 ºC) it enables 65 times less leakage[1 ] In addition to representing an important improvement over PEEK, Vespel® SP-21 parts with high thermal stability enable the stem pack from Oliver Twinsafe® Valves to:

  • Reduce leakage by >98% vs. MESC 77/300 class B standard at ambient temperature

  • Preserve its sealing capability at 350 ºC and at -50 ºC, reducing 90% of leakage vs. acceptable levels

  • Consistently allow >95% fewer leaks vs. acceptable levels1 in less extreme conditions.


[1 ]Test pressure = 300 Class. Test media = Helium 97% minimum purity. Acceptable leakage rate - 7.12 x 10-5 mbar.l/s. 

“Oliver Valves Ltd. and DuPont have achieved a new milestone and may be considered an industry benchmark in reducing methane fugitive emissions,” said Rakesh Nambiar, Global Technical Manager, Vespel®. “If an improvement such as this could be extrapolated to the whole natural gas industry, the 2030 Net Zero Emissions Scenario could become a reality well before this deadline. The unique blend of thermal, mechanical and tribological properties of Vespel® enable the manufacture of valves that can also meet the most stringent sealing requirements such as for hydrogen storage and transportation. This collaboration is essential to our core purpose of using science and innovation to create a sustainable world.”

To learn more about this application and the broad Vespel® parts and shapes portfolio, visit the DuPont website.

About DuPont Electronics & Industrial

DuPont Electronics & Industrial is a global supplier of new technologies and performance materials serving the semiconductor, circuit board, display, digital and flexographic printing, healthcare, aerospace, industrial and transportation industries. From advanced technology centers worldwide, teams of talented research scientists and application experts work closely with customers, providing solutions, products and technical service to enable next-generation technologies.

About DuPont

DuPont (NYSE: DD) is a global innovation leader with technology-based materials and solutions that help transform industries and everyday life. Our employees apply diverse science and expertise to help customers advance their best ideas and deliver essential innovations in key markets including electronics, transportation, construction, water, healthcare and worker safety. More information about the company, its businesses and solutions can be found at Investors can access information included on the Investor Relations section of the website at

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DuPont™, the DuPont Oval Logo, and all trademarks and service marks denoted with ™, ℠ or ® are owned by affiliates of DuPont de Nemours, Inc. unless otherwise noted. Oliver TwinSafe® is a trademark owned by Oliver Valves Limited.

For further information, contact:

Adam King

(508) 599-0396

* Source: International Energy Agency (IEA)


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