We are your system partner in all matters relating to precise control of the exhaust gas recirculation rate, whether for diesel or gasoline engines, passenger cars, commercial vehicles, or industrial engines.
All our valves and actuators are from one single source, us. Whatever you need – high-pressure or low-pressure EGR, cold-side or hot-side installation, smart or non-smart, metal or plastic housings – the product we supply is always precisely tailored to your needs. What’s more, our competence portfolio goes far beyond manufacturing of sophisticated EGR valves.
We are in our element when it comes to challenging operating conditions or new engine concepts. In addition to our role as a provider of modular systems, we operate as a technological development partner who works in collaboration with you on the design and realization of EGR concepts compliant with the latest emissions and CO2 standards.
EGR-valves come as either plate or flap valves. Linear actuated plate valves provide higher internal leakage tightness in the closed position. In contrast, rotary flap valves generate significantly less pressure loss at the same flow rate. In addition, the two valve types differ due to the control characteristics determined by their geometries.
In terms of service life, commercial vehicles place significantly higher demands on EGR valves. A further difference lies in the typically long air paths in commercial vehicles. Up to now, this has led to the exclusive use of high-pressure EGR valves. In addition to this, there are differences between light/medium duty and heavy duty applications, which we address with smart and non-smart actuators.
Pierburg has been developing reed valves since the early 1990s. Due to the firing sequence, the exhaust gas mass flow from combustion engines comes in a series of strong pulses. Reed valves exploit this effect: the valve opens every time the exhaust gas pressure exceeds the charge pressure, which leads to an increase in the exhaust gas recirculation rate. This is the case in the mapping zones of engines with low to light pressure differentials. In the case of a strong, negative pressure differential, i.e. when the charge pressure is considerably higher than the exhaust gas pressure, the valve shuts and the EGR cooler is closed off. This improves the charging efficiency and the load response of the engine. By preference, the valves are installed directly behind the EGR cooler.
Reed valves are not always made of aluminum. As early as 2014, we began the series production of reed valves with plastic housings. They are used at temperatures of up to 250°C and bring the advantages of lower cost and lighter weight.
Highflow Reed Valves
A further evolutionary step forward is marked by our high-flow reed valve manufactured from plastic. Series production began in 2019. The valves impresses by doubling the exhaust gas mass flow with an identical intake flow cross-section. This brings clear packaging benefits for large engines with more than an 11-liter displacement.
The brushless actuators for commercial vehicles manufactured by Pierburg are optimized for the harsh hot-side engine packaging environment and extended lifetime required of today's commercial diesel engines. They are used in the exhaust gas and fresh air systems of medium to heavy duty vehicles, and in the industrial sector, and actuate flaps and valves up to 120 mm diameter via a CAN Bus with OBD ready software. All of our brushless actuators have a lifetime of 20,000 hours, fulfill ISO 16750, and can be used in 12 V and 24 V systems. They are produced within the Pierburg Competence Pool and benefit from synergies and many years of practical experience.
Heay Duty Actuators
Heavy duty actuators, in series production since 2012, are a robust solution for all flap control tasks. They are used at many locations in the power train in both hot and cold conditions, and are optimized for applications that require a linkage. Applications include the actuation of high-pressure exhaust gas recirculation valves or exhaust gas flaps, large flow rate fresh air throttle valves, and turbochargers applications such as variable geometry turbines and wastegates.
Compact Brushless (or Electrically Commutated) Actuators
The dimensions of the compact EC actuator are minimized. It fulfills the requirements of modern applications on both the “hot” and “cold” sides of the engine. The actuator is optimized for direct drive, but can also be used with a linkage. It is a robust solution for most scenarios including high or low-pressure exhaust gas recirculation, exhaust gas flaps, fresh air applications such as throttle valves, and turbocharger applications such as the VGT and wastegate. It can also be employed for the control of waste heat recovery systems with high flow rates.