Enclosure Protection Vents Keep Emissions Reduction Systems Working Smoothly

Industry: Automotive

Problem: Resolving leak issues in vehicle urea tanks which can lead to mechanical failure.

Solution: Donaldson’s enclosure protection vent (EPV) with Tetratex™ PTFE membrane, which keeps water and debris out of the urea tank.

A small but crucial enclosure protection vent from Donaldson is playing a major role in helping European automakers meet tightening pollution regulations. The protective EPV from Donaldson is installed in the vast majority of vehicle Selective Catalytic Reduction (SCR) systems, which limit nitrogen oxide (NOx) emissions— the main health hazard produced by diesel engines.

Donaldson has provided its enclosure protection vent to the leading manufacturer of emissions tanks since 2012.

As a diesel vehicle runs, an SCR reservoir positioned next to the diesel tank injects a mixture of water and the organic compound urea into the car’s exhaust system. Urea metabolizes nitrogen-containing compounds and breaks down NOx into simple water and nitrogen, reducing NOx by up to 85 percent and fuel consumption by eight percent, according to industry tests. The urea tanks could not function without Donaldson’s Weld-Fit EPV, which keeps water and debris out of the urea tank, and allows pressure to equalize as temperatures and altitudes fluctuate.

The wide range of climates and altitudes in Europe pose a potential to deform the urea tank as it expands and contracts. A deformation can trigger mechanical failure or automatically shut down the ignition when the car exceeds exhaust standards.

To address these issues more satisfactorily, the tank manufacturer approached Donaldson after numerous unresolved leak issues with an existing tank vent supplier. With more than 100 years of experience serving automakers, Donaldson engineers worked closely with the customer to develop a customized solution. The team met an aggressive 18-month deadline to design and validate a membrane enclosure protection vent that would deliver consistent flow rates, while integrating snugly and easily into tank housing on the assembly line. A critical cut-over date went smoothly, when all manufacturing plants of the OEM worldwide began installing the new Donaldson vent on the same day.

Now, more than five years into the supply Donaldson-OEM relationship, the collaboration continues. Donaldson has been working to supply the Tetratex™ ePTFE membrane carrier and housing as one assembly. Engineers are also working to mold a vent into the filler cap, which some automakers prefer. And, for a sizable customer of the manufacturer, Donaldson is supplying a 25-percent-smaller EPV to accommodate a specific vehicle model.

The auto market—and other markets that depend on diesel fuel—will continue to require the reliability and flexibility of Donaldson’s membrane vent technology as air pollutions standards tighten.

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