Aircraft are frequently designed so that the fuel tanks are incorporated into the wing structures. This necessitates installation of tubular components for conveying fuel from the fuel tank to various locations that are internal or external to the fuel tank. Frequently, the tubular components must interconnect with other tubular components or system components, such as fuel pumps. This requires a system for protecting the fuel tubes from electrical discharges in the tube interconnections that could result from electrical currents generated flowing through the tubing by electrostatic charging, lightning, faults, or shorts in the aircraft electrical system. Fuel inside a fuel tank is combustible and therefor it is necessary for the fuel tube connectors to be protected from ignition sources that could result from such electrical discharges.
Inside the fuel tanks of traditional aluminum aircraft, the transient voltages and currents coupled by lightning to tubing inside aluminum fuel tanks are small, without enough energy to ignite fuel vapor in the event of a spark. However with the transitioning of aircraft structural components from metal to non-metal composites, the threat of electromagnetic effects (“EME”) failures in composite wing fuel tanks are typically more severe than in metal wing fuel tanks due to the non-homogeneous nature of composite materials and/or the lower intrinsic conductivity of composite structures, both of which may result in (1) a higher lightning induced voltage applied to the systems through the connections of the systems to the composite structure, and (2) a higher lightning induced current generated by these voltages in internal systems, which if high enough, can produce sparking in the interconnections involving the systems with enough energy to ignite fuel vapor inside a fuel tank.
Any system for installing tubular components in an aircraft should also minimize weight. It is desirable that any system involve as few as possible parts to facilitate installation and maintenance. Therefore, systems and methods are needed to easily, inexpensively, and effectively provide for the installation and electrical isolation of fuel system components.
It is with respect to these and other considerations that the disclosure herein is presented.