AIRDOG / FUEL PREPORATOR FP80
(Functional Description and Installed Pictures)



Below you will find some pictures of the AirDog installed on our 2004 F350 project truck. We have installed the AirDog using an "Outside the Framerail" bracket. For accident liability reasons, current production AirDog units come with an "Inside the Framerail" bracket. (Note: the "inside the framerail" bracket requires sufficient clearance in front of the fuel tank and may not fit shorter wheelbase trucks. Call us if you think this might apply to you.)

We have also included a picture of the AirDog with the fuel filter removed. This picture is used to help explain how the AirDog works. For reference purposes, the flow path of fuel through the AirDog is as follows:

  1. Enters Inlet Port
  2. Drawn Through the Water Separator
  3. Passes Through the AirDog Fuel Pump
  4. Pushed Through the Fuel Filter
  5. "Clean" Fuel Exits to the Engine
  6. "Aerated" Fuel Returns to the Tank
Click Pictures Below for Larger Images And Descriptions:







Basic AirDog Air Removal / Fuel Filtration Process:

  1. Diesel Fuel is drawn into the AirDog under a High Vacuum condition.
  2. As the fuel enters the AirDog, it is pulled through the Water Separator Element to remove any large debris and water.
  3. Following the Water Separator, the fuel is drawn through the AirDogs fuel pump.
    • Up to this point, the fuel is under a High Vacuum. This causes the air bubbles in the fuel to grow in size due to the decreased atmospheric pressure.
    • As the fuel passes through the water separator and fuel pump, many of these bubbles will join with each other to form even larger air bubbles.
  4. Upon leaving the fuel pump, the fuel (now with larger air bubbles) passes into the AirDogs fuel filter.
    • The filter media in the AirDog does not easily pass the air bubbles. Instead, they gather on the outside of the filter element (dirty side) until they become buoyant enough to rise to the top.
    • Separated from the pressurized inlet, there is a regulated outlet passage on the "Dirty Side" of the filter where the air and fuel can be pushed out and back to the tank.
    • The 6 Micron Filter Media is Key to the function of this setup as it allows little to no air to pass. 3 Micron filter media is also available.
  5. The fuel (and a few air bubbles under 6 micron in size) pass through the fuel filter media into the "Clean Side" of the filter.
    • On the "Clean Side" of the filter, the air bubbles once again rise to the top where there is yet another regulated outlet passage that returns to the tank (note the gap between the threaded nipple and the standpipe)
  6. "Clean" fuel is sent to the engine through the standpipe that picks up at the bottom of the fuel filter.

This above is NOT intended to be a highly detailed technical description of all of the AirDogs inner workings. PureFlow Technologies holds several Federal Patents on the Air Separation technology they have been developing over the last 14 years. The newest of their Patents was granted in early 2004 to cover the advancements incorporated into the AirDog units.