3-stage filter removes particles and water from diesel fuel

For the new Chevrolet Cruze, MANN+HUMMEL has introduced a new, 3-stage filtration concept for diesel fuel in series which ensures a constant high separation efficiency considerably above 90% for the whole service life of the filter element. 

The newly developed, three-stage filter element with integrated particle filtration, droplet coalescence and water separation is designed to handle commercially available diesel fuels which contain biofuels, have a low sulphur content, and include additives. The separation efficiency of conventional single-stage filters with a hydrophobic filter surface area falls substantially during the service interval whereas the newly developed filter element from MANN+HUMMEL when new separates more than 94% of the water content and at the end of the service interval after 48,000 km the figure is still significantly above 90%.

There are obvious advantages for car drivers: corrosion and cavitation effects on injectors, valves and the electric injection pump which can lead to a system failure are now a thing of the past thanks to the innovative filter and separation technology of MANN+HUMMEL. The same is true for microbiological growth and corrosion processes which can arise due to free water and which result in the premature blocking of the fuel filter or lead to hole corrosion of the filter housing.

Particle and water separation in three stages
The innovative filter element from MANN+HUMMEL is designed for filtration on the pressure side, whereby diesel fuel flows from the outside to the inside of the element. In the first filtration stage particles are separated by the MULTIGRADE F filter medium. This ensures that the diesel fuel is as far as possible free of particles. This reliably prevents contamination of the following coalescence fabric and final sieve fabric. In the second stage, the water is retained in the coalescer in the form of fine droplets and brought together to form larger droplets. In the third separation stage the water droplets are separated by the hydrophobic sieve and prevented from following the fuel into the injection system.

The three-stage process of the filtration of solids, droplet coalescence and water separation is integrated in a single filter element. With this specialised development MANN+HUMMEL underlines its company philosophy of "Leadership in Filtration" and reputation as a competent and innovative solution partner to the automotive industry.

Background information: How does water penetrate diesel fuel?
Water enters the fuel tank and the diesel in a number of ways. The most common cause is the entry of water via the tank ventilation, via condensation effects and incorrect tanking. In many cases sub-standard fuel quality is also the reason for excessive water content in diesel fuel. The newly developed 3-stage separation concept from MANN+HUMMEL with functional separation of solid particles and water from the diesel fuel provides effective protection through its constant high performance and prevents damage to the fuel and injection system and engine, also over long service intervals.