Now Available: Direct Fit, Retro-Fit and Built-to-Spec DOCs and DPFs!

Northern Mufflers offer a range of direct-fit, retro-fit, and built-to-spec emission control solutions, to assist in removing harmful gases and particulate matter from diesel exhaust systems.

Anyone who has had anything to do with modern diesel vehicles and machinery would know advanced emissions control systems often come as standard. While these add-ons to the exhaust system can create challenges for mechanics and owners when not maintained correctly, they are essential for protecting the environment.

You may have heard the terms DOC and DPF, and perhaps even used them interchangeably. But what do these acronyms mean, and what is each device designed to do?

Diesel Oxidation Catalyst (DOC)

Diesel oxidation catalysts (DOCs), or purifiers, are used to eliminate or change the gases and vapours via a reaction within the catalyst to make them less harmful to the environment.

A DOC is a flow-through filter containing precious metals to remove toxic emissions from exhaust gases, such as hydrocarbons, carbon monoxide and unburned fuel and oil. Think of them like a catalytic converter for a diesel engine.

They are cost-effective, have low maintenance requirements and are very simple in design and operation.

Partial Diesel Particulate Filter (DPF)

Partial diesel particulate filters (DPFs) are used trap or filter particulate matter, to ensure they are not released into the environment.

A partial DPF is a flow-through metallic filter that removes over 60% of diesel particulate matter (DPM).

They offer low maintenance, low accumulation of soot particles, and almost no increase in back pressure - so may be suitable as an increased flow alternative to a wall flow DPF (more on this style below).

Best results are achieved when used in conjunction with a DOC.

Wall Flow DPF

A Wall Flow DPF consists of a ceramic honeycomb filter, blocked one end to trap over 99% of diesel particulate matter (including ultra-fine and nano particulates), allowing airflow only through the ceramic walls of each cell.

Northern Mufflers wall flow DPFs utilise passive regeneration, meaning heat from exhaust gases is used to burn off soot particles, requiring no active regeneration or fuel additives.

For best results use in conjunction with a DOC.

Where to from here?

For more information on each of these options, please visit our Emission Control Solutions page.

If you require a DOC or DPF, we can work with you through the design and manufacture process – please contact us with your specific requirements so we can assist.

We are also a supplier of aftermarket, direct fit DOCs and DPFs for many vehicle makes and models, including Caterpillar, Komatsu, Elphinstone, Normet, Doosan, Sandvik, Volvo, Hitachi, Atlas Copco and Jacon, as well as mainstream automotive and heavy vehicle manufacturers.