Conductance on hydraulic fittings using a soft metal interlayer

A method for providing protection against sparking as a protective feature in preventing an ignition source in a composite fuel tank in need thereof comprising:

• providing a composite fuel tank comprising;
• a carbon reinforced polymer material and
• a hydraulic system, wherein the hydraulic system includes a hydraulic fitting having an inner surface and a hydraulic tube having an outer surface, wherein the inner surface of the fitting is adapted to extend over at least a portion of the outer surface of the tube in coaxial relationship therewith;
• and a soft metal interlayer is incorporated between the inner surface of the fitting and the outer surface of the tube, wherein the soft metal interlayer is located in an area where the fitting engages the hydraulic tube upon swaging or installation under pressure, and wherein the soft metal interlayer is about 0.001 to about 0.010 inches thick.

A hydraulic system, wherein the hydraulic system comprises:

• a hydraulic fitting having an inner surface;
• and
• a hydraulic tube having an outer surface, wherein the inner surface of the fitting is adapted to extend over at least a portion of the outer surface of the tube in coaxial relationship therewith;
• and a soft metal interlayer is incorporated between the inner surface of the fitting and the at least a portion of the outer surface of the tube, and wherein the soft metal interlayer is about 0.001 to about 0.010 inches thick.