The environmental demands placed on the hydraulic systems in large, heavy equipment can be extreme. Pressure, abrasive fluids, extreme temperatures and dirt can all impact the reliability and performance of the seals used to protect their mechanics. Fortunately for manufacturers producing construction, agricultural and mining machinery – among other, heavy-duty industrial applications – Freudenberg Sealing Technologies’ proprietary 94 AU 30000 polyurethane provides an outstanding solution.


The success distributors have witnessed with 94 AU 30000 seals is attributed to several key benefits. Sealing solutions made from the AU30000 material are not only resistant to water and synthetic hydraulic fluids but can handle major temperature and pressure fluctuations better than any other existing polyurethane on the market. They also offer very high extrusion resistance, allowing them to last longer under more challenging applications than other solutions on the market.

AU 30000 performance benefits are numerous. Seals and other components made from this bright blue, next generation polyurethane have benchmark capabilities in areas like compression set, tear strength, hydrolysis and extrusion resistance. They can be used to seal systems operating in very hot and cold environments ranging from -40°F (-40°C) to 248°F (120°C). They are resistant to mineral oils, biodegradable hydraulic fluids and water. They also offer a substantially longer service life, saving customers downtime and maintenance costs, especially in fluid-based applications where hot water and steam are present.

Significantly, 94 AU 30000 is highly effective when used to produce seals that come under extreme pressure. Test results indicate that 94 AU 30000 withstands 45 percent more pressure than the best material in the same class – 7250 psi versus 5000 psi. Tear strength under such punishing conditions is 61 percent higher than other PU materials. In a comparison test at 40 MPa and 100°C with large extrusion gaps, the seals made from this new generation of material show no appreciable signs of wear while conventional seals fail prematurely. This increases service life and resistance to wear. This means that cylinder makers can allow for nearly double extrusion gaps for the same operating conditions, reducing production costs. Or alternatively, significantly greater loads can be accommodated at the same gap width.

In addition to overall performance, seals made from AU 30000 can also reduce the number of needed parts in certain applications, resulting in easier installation and less downtime.

“Any time you can reduce a two-piece configuration to a one-piece without losing any performance, it’s obviously a benefit,” said Weber, Technical Director for a large sealing distributor. “One example is that when using a rod seal made from AU 30000, you no longer need an anti-extrusion ring with it due to its excellent performance under pressure.”

Freudenberg’s culture is driven through the principles of innovation, value and customer service, among other. AU 30000 addresses all of these areas, notes John Plut, Sales Director of Fluid Power for Freudenberg Sealing Technologies in the Americas.

“Freudenberg Sealing Technologies is focused on its customers’ success,” Plut said. “By pairing our material knowledge with our extensive understanding of the Hydraulic Cylinder Market, we have been able to develop breakthrough materials like AU 30000.”


The original article was written by Cheryl Eberwein, Director Corporate Communications, Freudenberg Sealing Technologies. This article has been slightly modified for Gallagher Fluid Seals' blog.

For more information about how this material could be a good fit for your application, contact Gallagher Fluid Seals today.