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Composite Isolators

AdelWiggins has pioneered technology in lightning strike protection for over 20 years in designing, testing, and manufacturing of dielectric fuel and hydraulic lightning isolators. Our dielectric lightning isolators are the preferred solution to meet regulatory requirements and are in service across multiple commercial and military aerospace platforms.


AdelWiggins has been supplying dielectric fuel and hydraulic isolators dating back to the 1990s. These isolators have been rigorously tested and qualified to most of the major aircraft OEM specifications. Dielectric isolators can be used on a variety of different fuel system types, such as: vent lines, jettison, supply lines, refuel lines, inerting lines, transfer lines, and motive flow. AdelWiggins’ dielectric fuel tubes can also be used not only in specific locations, but for the entire fuel system.

Dielectric fuel isolators can be custom designed to any configuration:​​

  • Tube resistance values can be modified per customer requirements

  • Both high and low pressure requirements supported

  • Standard or customized end fittings or flanges


  • Typical 100K to 100M Ohms of resistance

  • Can withstand 13 KV lightning testing per SAE ARP5412

  • Diameters of 0.5" (13 mm) to 4" (102 mm)


  • Lengths of 3.9” to 176.4


  • Typical ends include SAE AS1650, AS1710, AS1730, AS5830

  • Pressures (typical):

    • Operating: 125 psig (up to 600 psig)

    • Proof: 250 psig similarly for this and burst below

    • Burst: 375 psig

    • Higher ratings available

  • Temperatures (typical):

    • Air: -65 F to 180 F

    • Fuel: -65 F to 160 F

  • Fully qualified for environmental standards per RTCA/DO-160

  • Capable of mating with standard or special fitting ends

  • Compatible with several types of fluids:

    • Fuel

    • Hydraulic fluid

    • Solvent and cleaning fluid, etc.

  • Special connections or flanges (Sockets/Bulkheads/Panels)

  • Aluminum, Steel, or Titanium ferrule

Composite Fuel Isolators

Fuel Isolators

Composite Hydraulic Isolators

Hydraulic Isolators

Hydraulic dielectric isolators are devices that meet the stringent lightning protection and ESD requirements plus the more demanding hydraulic system performance requirements. Leveraging over 20 years of dielectric experience, AWG designed the 1st hydraulic isolators in 2005 through an extensive design, analysis, and test program. We have delivered over 1000 ship sets of hydraulic dielectric isolators. There are two basic configurations: inline and bulkhead.


  • Provide lightning protection

  • Dissipate static charge

  • Carry hydraulic system pressures

  • Meet CFR 25.613 statistical basis for strength allowables


  • Current conduction and voltage withstand without arcing/sparking

  • Pressure impulse cycles

  • Cyclic flexure loading

  • Operating, proof, and burst pressure

  • Dielectric isolation properties

  • Thermal insulation if required to surrounding structure threat loads (thrown tread, wing-tip tear-away)

  • Threat loads (thrown tread, wing-tip tear-away)


  • Operational ambient temperature

  • Hydraulic fluid cold soak and start-up

  • Hydraulic fluid continuous operating and transient temperature range

  • Hydraulic fluid temperature shock

  • Altitude

  • Vibration, shock, external static loads

  • Fluid exposure (jet fuel, de-icing agents, water, others per RTCA/DO-160)

  • Humidity

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