Exhaust emission aftertreatment

Emissions regulation Tier IV and Stage 3B

In terms of exhaust emissions the Year 2013 brought some challenges for manufacturers of off-highway engines. Besides the new emissions standard of the EPA in the US, new standards come into force in the EU as well. The new regulation "Tier IV final" and "EU97/68 Stage 3b" stand for a considerable tightening of the exhaust emissions. While the nitrogen oxides (NOx) and carbon monoxides (CO) in the lower engine-power classes continue to remain at the same level, the amount of diesel particulates need to be reduced drastically especially in the power classes above 19kW, which in some cases requires the use of a diesel particulate filter (DPF).

Tier IV final

Since 2008, the level "Tier IV final" for off-highway engines has been in force in the power class 0-8 kW and 8 - 19 kW. From 2013, this level also applies to the engines in the class from 19 to 37 kW and 37 - 56 kW.
The Hatz diesel B, D and G series engines have fulfilled these limits for several years and are the only small industry diesel engines in the market that meet these strict emission standards over the full line-up without significant additional effort. The only complicating factor is that the test cycles under which the emission limits must be adhered to will change in 2013. The introduction of the NRTC (Non-Road Transient Cycle) with the NTE (Not To Exceed) limits required a major development effort and for some engines a performance reduction of up to 10% of the maximum power.
Engines of the L and M series need a diesel particulate filter in order to meet the new emissions standard, which for the 3 - and 4-cylinder versions is already in the final stage of homologation. The L43C an M43 engine series with DPF will be available by end of the 2nd quarter of 2013. Until the launch of the DPF equipped engine series all engines can still be sold with the so-called "TPEM flex-regulation". The 2-cylinder engines 2M41 and 2L41C fulfil the standards if operated below 19kW. Over 19kW of power the engine will not be available anymore.

EU 97/68 Stage IIIb

In contrast to the emissions standards of the EPA there are different emission levels for variable and constant speed engines in the EU. For engines which run on a constant speed there is an engine available for each of the Hatz engine families which fulfils the regulations already.
For applications where a variable speed engine is needed, there are some limitations for engines above 37kW. For these engines a DPF will be required in future, which will be available from the end of the 2nd quarter of 2013. In the meantime, the OEM flex-regulation will apply.

TPEM and OEM flex regulation

With help of the flex regulation an engine of the previous emission stage can still be sold in the US (TPEM) or EU (OEM) under certain conditions. Usually this special approval is time or quantity limited and is being issued by relevant authorities.