Fleet e-news speaks to Donaldson Filtration Solutions Liquid Product Manager Bruce Evans about the latest demands for fuel filtration products?
What fuel filtration demands are you receiving from local government?
There are two distinct areas. There’s on-vehicle filtration and there’s bulk-storage filtration.
The main driving force behind the demand for on-vehicle filtration is because most of the newer engines are tending to be common-rail turbo diesel. These have a much lower tolerance of fuel contamination than older engines. If the fuel is not clean, there can be some significant maintenance costs involved.
The demand for bulk fuel storage is driven by the fact there is only so much an on-board filtration system can do. Many engine manufacturers are also stipulating the cleanliness level of the fuel being put into vehicles fuel tank. So the best way to achieve the cleanliness we require for the vehicle is to make sure the fuel kept in storage is pretty clean and dry to start with.
How common is it for local governments to operate filtration within their bulk storage?
Most workshops store fuels and oils. This provides the advantage of controlling the costs, but it also means the cleanliness level of the fuel can be controlled.
Some councils have fairly old infrastructure, but more and more are installing new storage infrastructure. The advantage of the new infrastructure is you’re starting off with clean fuel tanks, so you can control the cleanliness. The older tanks may have many years of accumulated sediment and water, and even microbial growth, sitting in the tanks, so it can be a challenge to get them cleaned.
We’re commonly asked for information about fuel cleanliness, so I think you’ll find that many councils will be asking for assistance in this area. A lot of sites will need to review their contamination control practices within their depots as lot of fuel contamination is added because of dated handling methods.
Have these demands sprung up recently?
Yes, quite recently. They’re being driven by the new emissions standards used in Australia and around the world. As one means of achieving these standards, the engine manufacturers have had to change the way their engine management systems work quite dramatically.
One thing they’ve changed is the injector pressure into the engines. In the past, injectors would pump fuel into an engine at 800-1500 psi. There would be a single squirt of fuel with each stroke.
Now they’re injecting up to seven times per stroke, under much more control. To be able to do that, they’ve had to increase the pressures the injectors operate at dramatically. They are now operating well in excess of 30,000 psi, some of them even up to 42,000 psi.
The good side is that they’re able to deliver more power, use less fuel and release fewer emissions. The down side is that they are far less tolerant of contamination.
Things that didn’t matter before, matter now. There are two main sources of contamination, sediment – or dirt – and water.
Another issue is that fuel tends to degrade quite quickly now. One other change is that our fuel is now ultra-low-sulphur diesel.
The sulphur did have advantages, one of which was that it provided lubrication to the top of the engine. When they took the sulphur out they needed to include additives and surfactants into the fuel to restore the lubrication. Some of these additives react badly with any water present in the fuel, so the fuel needs to be dry.
What developments do you foresee over the next couple of years?
Essentially it will be a progression of the changes that are already underway. There will be an increasing use of bio blends of diesel, and emission standards will continue to evolve.
The injector manufactures specify that almost completely clean fuel is required to achieve the maximum lifespan of the equipment. That’s very difficult to achieve just with on-vehicle filtration. Maintaining clean and dry bulk fuel storage is becoming an integral part of maintaining vehicle fleets.