Exhaust Valve

Valves allow for back pressure optimization of exhaust systems. Moreover, valves facilitates muffler standardization and help to reduce product and tool costs.

By using exhaust valves it is possible to reduce muffler volume by up to 30% and weight by up to 10% compared to a system without a valve. This further contributes to fuel efficiency, ultimately resulting in lower CO2 emissions.

Concerning acoustical benefits, the exhaust valves allow for a possible tailpipe noise reduction of 5dB to 10dB.

In addition, valves are used for sound design to give vehicles a specific characteristic, as well as for achieving acceptable sound quality, especially for downsized engines.

SAMTM (Semi Active Muffler):

Tenneco developed the Semi Active Muffler, which can be used either as middle or as rear muffler. Part of this muffler is a passive valve, the so-called SAM valve. The SAM valve is able to adapt muffler systems to engine load and rpm, and makes it possible to meet acoustic targets without external control.

Special versions of the SAM valve are available for high temperature applications, as well as developments that offer a vacuum actuation. SAM valves have been in serial production since 1998. Tenneco is the owner of several patents.

 

Electric Valve:

Electric valves will replace vacuum actuated solutions that are currently state of the art in the area of active valves. For car manufacturers, electric actuation means fewer control system components compared to vacuum actuation, resulting in lower overall costs (dispensing with vacuum generation, vacuum pipes, vacuum tank and electro-magnetic control valve). Moreover, operation of the electric valve is totally independent of the vehicle vacuum status and the system is less prone to failures.

Tenneco's electric valve uses a simple and modular design that can be easily adapted to different installation spaces and specific tube diameters.

Depending on the actuator type, open/close positioning as well as intermediate positions are possible. Electric actuators also offer the possibility of speed control in order to slow down the disc rotation speed before reaching the closed position,  thus avoiding switching noises that often come along with vacuum actuated valves.