In 2004, the United States Environmental Protection Agency (EPA) set new emissions standards – Tier 4 Standards – for non-road diesel engines. These standards are designed to reduce emissions by as much as 90 percent or more, according to the EPA.
Since 2004, construction equipment manufacturers have been working diligently to meet these Tier 4 standards by developing new, greener solutions including:
- Selective catalytic reduction (SCR)
- Cooled exhaust gas recirculation (CEGR or EGR)
Many construction equipment manufacturers are using SCR, CEGR or EGR, or a combination of the two to meet Interim Tier 4 standards.
The Difference Between SCR and CEGR/EGR
-SCR is an after-treatment only system. It creates a chemical reaction by adding diesel exhaust fluid (DEF), transforming the NOx into nitrogen and water, which occurs naturally in the atmosphere.
-In a CEGR system, exhaust gases are cooled and blended with fresh air, then returned into the cylinder. This helps lower combustion temperatures and drastically reduces NOx. However, the cooler combustion temperatures produce higher PM levels, which require an after-treatment diesel particulate filter (DPF) system.
Tier 4 technologies will not add any complexity to the operation of construction machinery. In fact, operators should find it easy to check DEF levels on SCR-equipped machines, and to check the diesel particulate filter on machines featuring the CEGR technology.
If you have any questions about EPA Emissions Regulations (Tier 4) or if you have a construction project that you need completed right the first time, please contact Reliable Contracting by calling 410-987-0313 or visit our website.
Reliable Contracting maintains a reputation as a leader in the construction industry. Our clientele includes builders, developers, individuals and government agencies. With projects ranging in cost from $10,000 to over $10 million, Reliable can be seen working on Maryland’s roads, highways, airports, office parks, shopping centers, hospitals, churches, and residential neighborhoods earning our reputation by providing clients with consistent quality and dedication to their projects.
Reliable Contracting Company serves the following and surrounding Counties: Annapolis, Queen Anne’s, Anne Arundel, Baltimore, Baltimore City, Calvert, Caroline, Charles, Howard, Prince George, St. Mary’s, Talbot, and Washington D.C.
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