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The Value of Active DPFs in Tier IV System Compliance

The Value of Active DPFs in Tier IV System Compliance

Diesel engine emissions contain particulate matter (PM) and nitrogen oxides (NOx) that have negative impacts on human health and the environment. Potentially carcinogenic PM consists of tiny particles suspended in the air and is a known cause of both respiratory and cardiovascular problems, while NOx is a group of gases that contribute to the formation of ozone and smog, impacting health and contributing to climate change.

The EPA has introduced a tiered progression of emissions standards with a targeted focus on non-road diesel engines. Tier IV standards are the most advanced engine emissions standards implemented to date, with strict financial penalties for violations.  In addition, the state of California Air Resources Board (CARB) is at the forefront of quality standards, with even higher air quality standards in its defense of public health betterment.

To meet these standards, engine manufacturers must use advanced technologies such as exhaust gas recirculation, diesel particular filters and selective catalytic reduction.

What is the role of a diesel particulate filter in a Tier IV System?

A critical component of a Tier IV-compliant system is a diesel particulate filter (DPF). DPFs are exhaust after-treatment devices that can be fitted to a wide variety of engines. DPFs work to reduce exhaust emissions through trapping exhaust particulates in the filter, thus removing many harmful emissions from ever entering the air.

Over time, DPFs need to be cleaned to remove the buildup of captured particulate matter. This cleansing’ occurs when the DPF system enters regeneration mode. In addition to regeneration, the filter must be periodically cleaned to remove the trapped noncombustible materials and ash.


Active vs. passive regeneration in DPFs — what’s the difference?

Passive DPFs. A cold passive filter will only trap particulate matter. Passive regeneration occurs when an engine operates at significant load, passing elevated exhaust into the system. This elevated exhaust heats up the DPF, burning off the trapped particulate matter (PM) in the filter.

Passive filters are not self-cleaning. A common issue with passive DPF systems is the deactivating of cleaning cycles because of untimely regenerations leading to the build-up of soot and particulate which can clog the filter. This can disable the unit and trigger costly downtime and repairs.

Active DPFs. Unlike passive DPFs, active DPFs are self-regenerating through an automatic process that occurs without a minimum exhaust temperature, even in idle mode. Heaters or load banks are not required to elevate exhaust temperatures for filter cleaning. Active DPFs can perform automatic regeneration regardless of the number of cold starts and engine run time.

The downside of using passive DPFs in Tier IV systems

Downside to Passive DPFs

Although the cost can be less upfront, passive filters have limitations that can become quite costly over time. The downsides of using a passive DPF in your Tier IV system include:

  • They require routine maintenance and supervision.
  • Operators must follow passive filter service guidelines, particularly related to the tracking of cold starts, for proper operation.
  • The exhaust restrictions that come with DPF filters increase back pressure, causing engine strains that can harm the integrity of the engine over extended periods of time — and can even trigger engine failure.
  • They may require up to 60 minutes of increased engine load before reaching the temperature required to combust the PM. This process leads to significant amounts of fuel consumption and cost.
  • They require a load bank or separate heater for proper cleaning, and the increased run times require additional costly fuel inputs.
  • Once a passive DPF becomes clogged to the point where it will not activate and maintenance will not be effective, it must be replaced.


The value of an active DPF in a Tier IV compliant system

Rypos active DPFs provide a simple and low-maintenance solution to Tier IV PM compliance for both new and older diesel engines, removing up to 95% of PM immediately upon installation, as well as reducing hydrocarbons, carbon monoxide and NO2.

Other filter manufacturers claim to have active regeneration, but only Rypos’ proprietary active DPF technology provide the only true self-cleaning filters that maximize the safety, reliability and uptime of your engines and generators. In addition, they are the only CARB-verified active DPF on the market.

“Most engineers or operators simply don’t realize the benefit of a true self-cleaning DPF,” notes Roberto Montero, Rypos Western Region Sales Manager. “The only maintenance a Rypos solution requires is an occasional visual inspection. It’s total ease of mind. Passive filters need frequent upkeep and can even fail, leading to engine damage.”


Whether you manage, data centers, hospitals, port cranes, or other diesel-powered equipment, Rypos can help you make an immediate impact on your environment and positive momentum toward Tier IV compliance.

Ask for a Tier IV solution with a Rypos active DPF today.

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