Aerospace Fuel Systems

Jet fuel is prone to solid particulate contamination, water and biological contamination. Removal of this contamination is critical to the reliable operation of onboard aircraft fuel systems. For details on filtration solutions for fuel systems, contact your local Pall sales representative at

Problems Caused by Contamination

Microscopic examination of contamination found in used fuel filter elements

Magnification: ~ 50X
Scale: 100 micron
Magnification: ~ 100X
Scale: 100 micron

The fuel system can contain particulate, water and biological contamination, which can come from several sources:
  • Debris built-in during the processes involved in the manufacture of the fuel system and its components
  • Wear debris generated during operation (e.g. metallic debris, seal debris)
  • Contamination from fuel storage and/or delivery systems
  • Products of fuel breakdown
  • Water from the environment
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This contamination can cause both immediate and longer-term damage to fuel system components. It can:
  • Block or erode nozzles and valves
  • Cause wear of fuel system components
  • Cause leakage (e.g. particles trapped under valves)
  • Cause corrosion of fuel system components
  • Foul sensors
  • Gum together surfaces
  • Cause fuel degradation
Note: A common mistake by operators when short filter life occurs is to install a coarser filter to extend filter element service life. However, the element was blocking because the fuel was contaminated thereby protecting downstream components from damage. A coarser filter will not provide the protection required, and will lead to more problems, such as component wear and ultimately, equipment failure.

Benefits of Filtration

Selecting the appropriate filtration solution will:
  • Improve the operating reliability and performance of the fuel system
  • Significantly reduce maintenance costs
  • Extend component service life
The optimum performance is achieved by selecting the correct filter rating, size, and location. Pall technical experts can help you with this selection.

Typical On-Board Filter Locations

  • Main engine fuel filter located within the pump
  • Wash flow filter for fuel control systems
  • "Last Chance" filters upstream of critical valves, fuel controls, etc.
  • Coarse screens downstream of transport pumps from fuel tank to engine

Filter Solutions

On-board filtration products include:
  • Filter Assembly
  • Filter Element
  • Differential Pressure Indicators/Switches
  • Last Chance Filters
For the complete bulk fuel delivery process, here is an overview of all the filtration solutions available from Pall

To determine the best product for your application, contact your local Pall sales representative at

Technical Papers/Standards

Madhavan, P. (September 2004) "Filtration Technology for Aircraft Gas Turbine Engine Fuel and Lubrication Systems", Aircraft Technology and Maintenance, 2005 Engine Year Book

SAE Aerospace Recommended Practice (ARP) 1827 "Measuring Aircraft Gas Turbine Engine Fine Fuel Filter Element Performance"