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May 01 2019
By The routeone team

The routeone team is dedicated to bringing you the latest bus & coach industry news, views, jobs and more.

Keeping DPFs clean to ensure Euro 6 standard

The introduction of London’s Ultra Low Emissions Zone (ULEZ), which mandates Euro 6 compliance for coaches and buses, brings the need for coach and bus operators to ensure diesel particulate filters (DPFs) are correctly maintained into sharp focus. 

Stay Euro 6 compliant with Imperial Engineering and Ceramex

PSVs with a gross vehicle weight (GVW) of over 5,000kg that are not ULEZ compliant face a £100 daily charge, while minibuses with a sub-5,000kg GVW are subject to a fee of £12.50. 

Buses with DPFs retrofitted to make them Euro 6 compliant, in addition to those equipped with OE DPFs, now make up around three quarters of the capital’s 9,200-strong bus fleet, according to data from Transport for London (TfL). This equates to around 6,950 DPF-equipped buses operating in London, all of which require regular cleaning to ensure Euro 6 and ULEZ compliance is maintained.

To help operators meet this challenge, Imperial Engineering has established a partnership with Ceramex, a world-leading provider of DPF cleaning services. 

By utilising its patented and OEM-approved Xpurge technology in a chemical and oven-free process, Ceramex is able to offer operators the highest possible cleaning success rate to ensure their vehicles remain Euro 6 compliant. 

Compared to conventional DPF cleaning methods, which only tend to remove soot deposits, Xpurge also removes residual ash deposits to ensure a fully-cleaned DPF that’s effectively as good as new.

Removal of both soot and ash deposits makes a fundamental difference in terms of performance, enabling longer service intervals for DPF cleans, fewer failures due to hard ash deposits and less expensive DPF replacements. 

DPFs cleaned using Xpurge technology also ensure optimum fuel consumption as conventionally cleaned DPFs where residual ash deposits are still present can result in a vehicle consuming up to 7% more fuel and significantly increased running costs for operators.

It is also vital to examine the condition of the DPF after cleaning. In order to achieve this, Ceramex uses a range of inspection technologies to ensure that the cleaned DPF will perform as well as when it was new, and that Euro 6 compliance is maintained. 

Ceramex’s most comprehensive test method is the Veritex inspection system. This patented process uses transmitted light to investigate the internal condition of the DPF after cleaning and can identify any remaining blockages in the filter, as well as holes, cracks and other forms of damage to the unit.

Working in partnership with Ceramex, Imperial Engineering offers an exchange-based DPF cleaning service which is designed to help operators minimise vehicle downtime and keep their fleets Euro 6 and ULEZ compliant. 

To find out more, please call 01992 634255, email or visit

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ADL 2019