Abstract: An improved sheathed cable and method for producing same is described. The cable includes an inner insulated conductor/conductor group, an outer corrugated metal sheath, and a barrier layer of a pliable, inert sealing material disposed therebetween to prevent the passage of gas or vapors via the cable. The method includes the steps of applying the pliable material around the inner insulated conductor/conductor group, wrapping the pliable material with a flexible tape, forming an outer metallic sheath around the material, and making annular corrugations in the outer sheath so as to compress the sealing compound.

Abstract: An improved method for producing sheathed cable which includes an inner insulated conductor/conductor group, an outer corrugated metal sheath, and a barrier layer of a closed-cell foam disposed therebetween to prevent the passage of gas or vapors via the cable. The method includes the steps of extruding a heat activated closed cell foam about the insulated conductor, forming an outer sheath around the foam, and activating the foam to fill the space between the inner and outer sheaths. In accordance with varying alternative embodiments of the invention, the extruded barrier foam layer may be continuous or interrupted; and/or may comprise an already foamed material compressed by formation of the outer metallic sheath.

Abstract: An improved method for producing sheathed cable which includes an inner insulated conductor/conductor group, an outer corrugated metal sheath, and a barrier layer of a closed-cell foam disposed therebetween to prevent the passage of gas or vapors via the cable. The method includes the steps of wrapping a strip of heat activated closed cell foam about the insulated conductor, forming an outer sheath around the foam, and activating the foam to fill the space between the inner and outer sheaths. In accordance with varying alternative embodiments of the invention, the barrier strip may be continuous or interrupted; and/or may comprise an already foamed material compressed by formation of the outer metallic sheath.