The filter is one of the most important elements within a fuel dispensing system, although it is not mandatory. What is it? What is it for? We talked about filters with Alberto Madella, Customer Care director of PIUSI to clarify and answer any doubts that may arise around the topic of filters.

Q: ”PIUSI filters are useful for pre-filtering in a dispensing system. What does that mean?”

A: “Our filters are useful to purify the diesel contained in the tank in order to lower its contamination level and thus allow the filters already installed in the engine (of the vehicle) to work longer and perform better while staying protected from the aggressive agents that may be contained in the fluid itself.

This is the main function of pre-filtering: to act as a protective shield for the transfer of fuel in the tanks of vehicles; such as – for example – in a farm tractor”.

Q: “So, are you telling us that this kind of PIUSI filter has to be installed inline on the suction hose?”

A: “On the contrary, they have to be installed in the delivery part of the system. This is for two main reasons: if installed on the suction hose, the filters can clog quickly and easily due to impurities already present in the tank – for example water or contaminants on the bottom of the container – and therefore reduce the pump flow rate and, moreover, create a “cavitation effect” that can damage the pump itself over time.

PIUSI filters for pre-filtering have to be installed on the delivery hose to benefit from all the pre-filtering effects of protection for the engine, without disadvantages of cavitation and use”.

Q: “But why would the fuel contained in a tank be contaminated?”

A: “This is a situation much more frequent and simpler than expected. Even if closed, some air enters into the tank due to its emptying as a result of the dispensing operation made. This allows some humid air to enter into the tank during each delivery. As a result of heating and cooling cycles (night/day), especially if the tank is placed in a sunny area, condensation (water) can form inside the container and deposit on the bottom of the tank (because it is heavier than the fuel itself).

So, it’s very easy that the pump sucks up this water, because the suction hose is at the bottom of the vessel, that can be delivered into the vehicle’s tank. Moreover, we should also consider the quality of the fluid purchased and also the transfer procedure from the truck barrel to the tank.

Last, we should also consider the “coffee bottom” effect: if the tank is placed in a very dusty area, the air that enters the vessel is full of small particles (dust) that group together and deposit on the bottom of the tank. If the container is never cleaned, this deposit increases in volume over time and is gradually sucked by the pump and can be transferred into the vehicle, if not filtered”.

Q: “ What types of filters does PIUSI offer and what are their main features?”

A: “All PIUSI filters have some common features – for example, cartridge filters – and some specific details. The water captor filters are useful to absorb all water particles that may be mixed into the fuel in the tank.

We also have some filters for biodiesel that, being a much more aggressive fluid than common fuel, need specific materials.

Moreover, we also have a full range of cartridge filters with transparent containers that may also be used as a water captor. The transparent container allows you to see how many impurities have been filtered, giving a clear visual idea of how much the fuel in the tank was contaminated.

The transparent container also allows for a much more accurate and faster maintenance of the cartridge itself that can be replaced before it is permanently blocked. Within this range of filters, we also have a filter with a metallic cartridge; a sort of sieve with a reduced filtration capacity – due to the dimension of the metallic cartridge – that can be used for pre-filtering operations for a pump or in line with other filters to extend the life of the pump or of the vehicle tank. This cartridge is washable and can be re-used.

We also have some more traditional filters for oil and fuel. All of them with specific features and ℬ efficiency rate.

We also have a special filter for AdBlue®/DEF that, thanks to a 3-step filtration, is useful to preserve the quality of the dispensed fluid for a longer life of the catalyst”.

Q: “Can all the PIUSI filters be installed in an existing system?”

A: “Yes, for sure. All the filters are suitable for any retrofit because they are designed and engineered with an in/out connection already threaded and thus easy to install.

However, it is important to keep in mind that not only old, but also new systems can be full of impurities. The new installation sucks from a brand-new tank that may contain many particles and impurities (welding dust, electrode parts, paint residues, plastic parts, etc.) and, in this case, it is very important and strategic to install a pre-filtering system to prevent impurities that can be transferred to the vehicle’s tank. A kind of filter such as ours is useful to protect the pump itself and the vehicle’s motor”.