Did You Know: the "VACUUM FEED FILTER SYSTEM" currently on your engine passes entrained air to the engine and increases transfer pump cavitation and vapor as the fuel filter plugs with use. 

This is the source of the performance issues previously stated? 

AIR BECOMES ENTRAINED  in diesel fuel from sloshing and agitation. Vapor develops from pump cavitation.

Air/Vapor in Diesel Fuel in Common Rail Engines Adversely Effects the Injection Rate and the Spray Pattern! This causes increased fuel consumption & increased exhaust emissions! 


With Air & Vapor present in the fuel, the effective stroke of the High Pressure Pump and output volume of fuel to the Common Rail is reduced. This adversely affects both the injection rate and the shape of the injection spray pattern. This results in increased fuel consumption and increased exhaust emissions, especially unburned hydrocarbons and Nox. AirDog® removes the entrained air from the fuel and prevents the formation of vapor in the high pressure pump to restore the efficiency of the Common Rail System.


Air/Vapor in Diesel Fuel

in Unit Injector and Injector Pump Engines

Retards Injection Timing! This causes increased fuel consumption, increased exhaust emissions and lower power output!


Air & Vapor are compressible. When air bubbles and/or vapor are present in the fuel, the injection is delayed until the air/vapor is compressed to the injection pressure. The delayed injection results in Retarded Injection Timing, Resulting In...Increased Fuel Consumption, Lower Power Output and Increased Exhaust Emissions!


AirDog® Industrial Systems feature Positive Fuel Air Separation technology, New 4G-HD Fuel Pump, a Low Pressure Indicator sensorDemand Flow, and Adjustable Regulator!

The AirDog® Removes the Entrained Air from the fuel flow to the engine and maintains a Net Positive Pressure Head to the transfer pump preventing cavitation and vapor. Regardless of whether your engine has a Common Rail, Unit Injector or Injector Pump system, it can now perform at maximum efficiency, as it was designed... FOR Increased Fuel Economy, Increased Power Output and Longer Injector Life.

PureFlow® Technologies also manufactures 12 and 24 volt fuel pumps!

AirDog®, Fuel Preporator® and Raptor® are registered trademarks owned by CD Patents, LLC. All Patents, United States & Worldwide, embodied in AirDog®  Fuel Preporator®, and Raptor® products are also owned by CD Patents, LLC.


PureFlow® Technologies, Inc. Manufactures, Advertises, and Sells AirDog®, Fuel Preporator® and Raptor® Products under Authority of Patent Licensee Agreements with CD Patents, LLC.



PureFlow AirDog®, Shelbyville, IN, Manufactures, Advertises and Sells AirDog® Fuel Air Separation Systems and Raptor® Fuel Pumps for Pick-up Trucks by way of Manufacturing and Sales Agreements with PureFlow® Technologies, Inc. & Intellectual Property License Agreements with CD Patents, LLC. 





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PureFlow® Technologies’ website may contain links to other websites. PureFlow®Technologies is not responsible for the privacy practices, copyright, or content of such websites.


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PureFlow® Technologies, Inc.

5508 Business 50 West

Jefferson City, MO 65109

Toll Free:1.877.GO DIESEL


Direct: 1.573.635.0555

Fax:     1.573.635.0778



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8 PG AirDog Commercial Brochure 2013.pdf
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How Does Air Become Entrained In Diesel Fuel?


As in all liquids, air becomes entrained in diesel fuel from sloshing and agitation! Air can be on the surface of the fuel in the form of foam or it can be in the bulk fluid in the form of tiny bubbles. Entrained Air is an issue of an "in use" engine in operating equipment!


What is Pump Cavitation?


Pump cavitation, simply put, is the pump not having enough pressure flow, or "Net Positive Pressure Head" of fuel coming into the inlet to completely fill the vacuum chamber of the pump.


Diesel fuel, as is true with all petroleum base liquids, will give off vapor when subjected to a vacuum. The amount of vapor depends upon the level of vacuum and temperature.


How Does Fuel Filter "Restriction" Effect Cavitation?

In the diesel engine industry, "fuel filter restriction" is a term that refers to the vacuum level at the inlet to the transfer or lift pump. It is measured in inches of mercury (in hg).


As the filter plugs with use, it further restricts the flow and increases the vacuum level in the pump.


The amount of vapor produced depends upon the level of vacuum.


What Else Increases Cavitation and Vapor? 


As the fuel levels in the tank(s) goes down as the fuel is burned, the "Dry Suction Lift" increases. This reduces the flow, increasing the vacuum.  


Operating at higher altitudes, where atmospheric pressure is less, reduces the fuel flow and increases vacuum. For example, at Denver,  atmospheric pressure  is about 17% less than at sea level and at Eisenhower Tunnel, it is approximately 32% less. Having less pressure to drive the fuel from the tank to the transfer pump, reduces the flow and increases the vacuum levels.


Higher fuel temperatures cause more vapor to form than cooler fuel under the same vacuum!