New High-Performance Seals for Butterfly Valves

picture of custom butterfly valve sealsValves for the process industry must meet particularly high demands in terms of hygienic design, industry-specific approvals and resistance to CIP/SIP media. This also applies to the seals. Gallagher Fluid Seals’ partner, Freudenberg Sealing Technologies, has developed a new series of high-performance seals for butterfly valves. This was done in cooperation with their French customer Definox.

FST customer Definox needed a specific sealing solution for the development of a new series of high-performance butterfly valves.

The goal was to find the ideal combination of uncompromising tightness, simple installation, dead space-free sealing geometry and wear-resistant materials.

With this premise in mind, the FST dev team began designing. In an initial phase, the team performed extensive validation tests of the new valve seal on the in-house test stand. The experts tested seals in three reference dimensions under real conditions in original Definox valves. The results of the long-term tests could then be transferred to other seal dimensions. This method provides reliable information about the seal properties while also saving time and money in the development process.

Validated on the Freudenberg Test Stand

The test stand is designed as a CIP system with multiple containers that makes it possible to simulate various cleaning processes with acids, lye and disinfectants. Up to three valves can be tested simultaneously or successively on test tracks. Operating parameters such as temperature, pressure and flow rate are recorded digitally. The inspections provide tested findings on the material’s resistance and functional reliability – and thus important information for choosing the appropriate seal.

This cooperative project has resulted in an innovative butterfly valve seal whose combination of wear-resistant materials and innovative design is a perfect fit for the demands of the process industry. Butterfly valve seals should close with little force and, when closed, have high compression to ensure the sealing function. The sealing geometry also has to be developed free of dead space and leak-free to meet the demands for hygienic design. The new sealing solution from Freudenberg Sealing Technologies excels with very good pressure resistance and extremely low torque. The pressure resistance is maintained multiple switching operations. These properties guarantee a long service life and high reliability even under challenging operating conditions.

Materials with high media and temperature resistance

The customer was convinced with FST’s new, high-performance butterfly valve seal, which has been tailored to meet specific requirements. Enough so, that more products were determined to have tailored seals per the customer.

The resulting projects created a series of butterfly valves with different dimensions, which are available in the three FDA- and EU (VO) 1935/2004-compliant materials 75 EPDM 253356, 75 Fluoroprene® XP 41 and 75 HNBR 254067.

Thanks to the cooperation with FST’s customer, Definox, the new high-performance butterfly valve seal now provides the process industry with a sealing solution for butterfly valves that is optimally designed to meet its demands.


The original article was written by Ulrike Reich, Head of Media Relations & Internal Communications and Cheryl Eberwein,
Director, Corporate Communications at Freudenberg.

Gallagher Fluid Seals is an authorized distributor for FST. For more information, or if you have an application that needs assistance, contact us today.