Partial Filter

The Partial-flow filter is an approved conversion device under the London Low Emission Zone (LEZ), It will allow heavier Euro2 vehicles to conform to the London LEZ requirements until 2012 and will allow light commercial vehicle to conform beyond 2012.

Cawdell supply and fit the product either at customer workshops or at our Derbyshire HQ, or at one of our fitting partners sites. For further information please contact us.

The Partial-flow filter performance lie’s between a full Diesel Particulate Filter and a Diesel Oxidation Catalyst. It has the same benefits as a diesel oxidation catalyst (DOC) in that there is no routine maintenance required. The particulate (soot) reduction performance is better than a standard DOC and typically achieves between 40% - 75%. Hydrocarbons and Carbon Monoxide will also be reduced by around 80% and therefore there should also be a noticeable reduction in exhaust odor.

This product is very suitable for applications where a marginal improvement in emission is required. For example the London Low Emission Zone 2008 requires a particulate emission level equivalent to the Euro3 specification, therefore a vehicle of Euro2 specification can be fitted with the Partial-flow which will give a 50% reduction in particulate – more than enough to comply with the Euro3 requirements.

There is no need for the removal of ash at periodic intervals (as is necessary with full filters), and there is no dependence on exhaust temperatures and vehicle duty-cycles for function of this product.

The filter assembly is made of a torturous-route corrugated metal foil that is coated with precious metals. As the particles are carried through the filter by the exhaust flow they impact the filter walls and become attached until they are oxidized by the catalyst.

Under rare conditions of very low exhaust temperature when oxidation is not possible, particles will agglomerate. If the engine is continued to operate under such conditions for lengthy periods the exhaust flow will cause the agglomerated particles to “tumble” through the filter until they are ejected. Therefore the filter unit cannot block.

The Partial-flow filter is suitable for Trucks, Vans, Buses & Coaches, and specialist applications.