Recirculation units are designed to be used particularly in circumstances where fuel is stored over long periods such as in generator supply tanks. The fuel in these tanks can become contaminated with microbial contamination (often referred to as diesel bugs which are micro-organisms that grow on water present in fuel) which can block engine filters causing down time. The units take the fuel in through an inlet filter removing any large particles, then through an anti-microbial pre-filter fuel conditioner preventing microbial growth and finally pumped back into the storage tank through a water/particle filter. The unit is programmed through a timer to suit the size of your storage tank and has a flow switch with indicator warning light to indicate the need to change the water/particle filter. Apart from the filtration of the fuel and the removal of the microbial contamination the recirculation of the fuel helps to keep it oxygenated thereby prolonging it’s life.