Flexible systems last the distance

Commercial vehicles rely on increasingly complex flow paths to handle gases and liquids in the engine and air-conditioning systems found on board.

In order to meet the ever-increasing demands of emission legislation the systems have to remain leak-free for the life of the vehicle while operating under high pressure and extreme temperatures, and being exposed to constant vibration and corrosion. One of the leaders in the design and manufacturing of flexible mechanical components and systems is the BOA Group which is headquartered in Stutensee, Germany. The group, with eight manufacturing locations world-wide as well as numerous sales and engineering offices around the world, specializes in finding solutions for complex challenges in the automotive, aeronautical and other fields. 

Automotive Industries (AI) asked Thomas Kraus, Vice President Business Development, BOA Group, why the company places so much emphasis on reliability in the commercial vehicle sector in particular.

Kraus: OEMs in the commercial vehicles sector have to overcome many physical and legislative challenges. Because commercial vehicles work under extreme conditions almost every day of the week to generate revenue for their operators equipment failure can be very costly, both in terms of lost revenue and repairs. At BOA we recognize these pressures and are working hard to ensure that our systems deliver the highest levels of reliability. 

As a result we offer a wide range of flexible systems for on-road trucks and buses, as well as off-road vehicle applications. In particular, modern automotive manufacturing requires exhaust systems with durable, gas-tight, flexible connecting elements which provide high endurance and corrosion resistance as well as maximum vibration decoupling performance to increase vehicle comfort and system durability. We meet these challenges with the BOA EnduroFlex range of products.
Other examples of BOA flexible solutions for commercial vehicle applications include exhaust gas recirculation (EGR) tubes, oil return lines, high frequency dampers for turbo-charged systems, intercooler routings, thermal compensators for compensation of temperature related stresses and highly flexible metal hoses for compensation of large axial, angular and lateral motion. We also bring our expertise to applications outside the engine bay. For example, our flexible hoses and expansion joints have numerous applications within a vehicle air conditioning or vehicle mounted refrigeration systems.

AI: What is the “BOA EnduroFlex” range of products?

Kraus: The introduction of international environmental and emission regulations (for example Euro V and Euro VI) has created the need for flexible, gas-tight connecting elements in heavy vehicles. This is a similar concept to the designs which have been used in passenger car applications for many years. However, the heavy-duty demands of commercial applications mean that much more engineering design and development work is required to achieve the reliability levels required by OEMs and their customers

As a market leader in the field of exhaust system decoupling we have developed a state of the art knowledge base, engineering tools, and testing systems over many years. This has enabled us to develop and produce customized solutions for the commercial vehicle sector. We call them “‘BOA EnduroFlex”.

AI: What advantages does the “BOA EnduroFlex” range offer?

Kraus: We guarantee our products will provide optimal performance for the lifetime of the vehicle – typically one million miles. The failure of a critical component in the exhaust system means not only that the vehicle will fail to achieve the required emissions standards, but also potentially risks damaging sensitive exhaust after-treatment components such as particulate filters and catalytic converters. With the BOA EnduroFlex range our customers can mitigate the risk.

AI: What are the other demands of the market, and how does BOA meet them?

Kraus: BOA has a long history and track record in the aerospace sector as well as high technology industries including semi-conductors. We bring all our engineering experience and capability together to create innovative solutions for our commercial vehicle customers. In today’s tough financial climate operators are expecting ever-increasing returns from their capital investment. As such, the reliability of vehicle systems is of paramount importance.

In addition to the traditional challenges of heat, pressure, corrosion and vibration, todays commercial vehicles also face the challenges of meeting the ever-increasing levels of emissions standards. The technical solutions required to meet this legislation creates extreme operating conditions, often in a corrosive environment. Urea injection in particular makes special demands on ensuring the longevity of engine components. Working in close cooperation with our customers BOA has introduced solutions that allow for urea injection before the flexible joint to the market.

AI: How much testing did BOA do for the development phase of these products?

Kraus: We conducted a comprehensive testing program for the EnduroFlex product range – not just in our own R&D facilities, but even more importantly through extensive in-field testing with our OEM customers all over the world. In our own R&D facilities we are able to simulate a multitude of stress and vibration testing scenarios using our six degrees of freedom (6 DOF) test rig. In addition, our environmental corrosion chamber allows us to undertake rapid simulation of the impact of corrosion with components being subjected to five years of corrosion conditions in just 12 months. To date we have amassed over 30,000 hours of testing in this chamber and our endurance testing program continues.

Our field testing program was conducted in a number of countries including Brazil, a nation where only 20% of the roads are paved. Through this field research we were able to collect significant amounts of data to demonstrate both how our own and our customer’s products behave under extreme conditions. In addition to using this information ourselves we were able to provide our customers with invaluable insight into their own product design. We were able to make suggestions for their chassis development, which led to significant overall cost savings.

The other point to remember is that, whilst we can design our products and systems to offer a million mile warranty, our experience and engineering capabilities are equally applicable for applications which are less arduous. BOA can offer a product of the optimum design to meet every customer’s exact and specific needs.