FARNBOROUGH, Hampshire, England (July 10, 2008) – Simrit, the industrial sealing products division of the Freudenberg and NOK Group, enhances aerospace applications with its specialized sealing solutions, materials and technologies. To highlight its material performance, the company recently released three new application case studies demonstrating the success of its E454 and E458 EPDM (ethylene-propylene rubber) compounds in real world applications.

Simrit’s materials and products allow its customers to keep passengers safe while in the air. With years of experience in the design and manufacture of elastomeric seals and custom-molded products, Simrit supplies major airframe manufacturers, prime contractors and subcontractors worldwide.

“Given industry demands, our aerospace customers require only the best quality products and systems to accurately manage their sealing needs,” said Dr. Bob Keller, manager of materials development for Simrit. “Since their debut in the market in 2005, our E454 and E458 compounds have performed exceptionally well in commercial aircraft hydraulic systems. As proof, major aerospace manufacturers who previously used competitive O-rings have recently switched to our E454 and E458 O-rings due to their excellent sealing capabilities.”

Simrit’s E454 black compound is compliant with NAS-1613 Rev. 5 requirements for O-ring packings designed for hydraulic systems using phosphate ester fluids. This material is intended for NAS-1611-XXXA and NAS-1612-XXXA (A-code) series O-ring.

Simrit’s E458 is also a black compound that is compliant with NAS-1613 Rev. 2 requirements for O-ring packings in high-density hydraulic systems using phosphate ester fluids. This material is fitting for NAS-1611-XXX and NAS-1612-XXX (no-code) series O-ring and has a permanent white stripe and white dot marking on suitable O-ring sizes.

As a testament to their success, Simrit points to the following case studies to demonstrate these compounds’ superior performance in real world applications.

Case Study 1: Simrit E458 and Power Control Unit

Issue: A major power control unit manufacturer using competitive O-rings was experiencing leakage of low density phosphate ester fluid. The leakage was occurring early in the life of the units – most often during the initial customer delivery – causing damage to the aircraft’s paint. The manufacturer was liable for the costly re-paint of the aircrafts.

Investigation: Testing and comparison of Simrit E458 O-rings to competitive O-rings in low-density phosphate ester hydraulic fluids demonstrated Simrit’s E458 O-ring was superior to competitive material in fluid resistance. Lengthy, long term cyclic power control unit tests by the manufacturer showed the superiority of Simrit E458 O-ring to competitive materials, as they demonstrated 100 times the leakage of Simrit’s E458 O-rings.

Solution: The customer is now switching its power control units to use Simrit E458 O-ring to prevent early life fluid leakage and damage to aircraft paint.

Case Study 2: Simrit E454 and Control System Spool Valve

Issue: A valve manufacturer using competitive O-rings was experiencing extrusion after four to five years of service. The debris from the ruptured O-rings were clogging and jamming the valves, therefore leading to flight control failures and the grounding of high-capacity commercial airliners.

Investigation: Testing and Finite Element Analysis by Simrit showed that the E454 compound will not suffer extrusion damage at the pressure and temperature extremes in the application valve. Cyclic testing by the valve manufacturer validated Simrit’s analysis.

Solution: The manufacturer is switching from competitive O-rings to Simrit E454 O-rings to prevent the extrusion problems and solve the flight control failure issues.

Case Study 3: Simrit E454 and Hydraulic Fittings

Issue: A major commercial aircraft was experiencing leaking of fittings using both low- and high-density phosphate ester hydraulic fluids. These fittings are in exposed areas where flight-crew walk-arounds detected the leakage and were grounding flights, causing delays and lost revenues for customers.

Investigation: Short- and long-term behavior testing and comparison by Simrit of the E454 O-ring to competitive materials demonstrated superior performance to competitive materials in both high- and low-density phosphate ester hydraulic fluids and compression sets. Cyclic hot and cold pressure testing of Simrit E454 and competitive materials by airframe manufacturer verified that Simrit E454 is the only material that showed acceptable performance in both high-density and low-density phosphate ester hydraulic fluids.

Solution: Airframe manufacturer issued service letter to customers recommending use of Simrit E454 for all problem applications.

Those interested in additional information about Simrit’s E454 and E458 EPDM materials can visit the Simrit booth (hall 3, stand B3) at the Farnborough International Airshow in England from July 14 to 20.

The Simrit Division is based at Freudenberg-NOK’s headquarters in Plymouth, Mich. and is part of the Freudenberg and NOK Group, which has total annual sales of more than $12 billion. Simrit offers an extensive portfolio of sealing solutions for the aerospace, appliance, diesel engine, industrial, marine, off-highway equipment, oil and gas, recreational vehicle and semiconductor markets.

For more information, visit the Simrit website at www.simrit.com.

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Editor’s note: For electronic images of Simrit’s E454 and E458 compounds, please contact Adriana Ferrari at 248-269-1122 or aferrari@bianchipr.com.