Elastomeric contamination seal

In combination, first and second compressible contamination seals, first and second discrete high-voltage gas-filled transmission line sections, and a backup welding ring;

• said first and second high-voltage gas-filled transmission line sections each consisting of substantially identical axially aligned first and second outer housings which are cylindrical in cross-section, the ends of said first and second outer housings which face one another being spaced from one another, a weld bead connected between and joining said spaced ends of said first and second housings, an elongated central conductor suspended within said first and second outer housings;
• said central conductor being generally circular in cross-section, and a plurality of support insulators axially spaced from one another along the axis of said elongated central conductor and connected between said elongated central conductor and said first and second housings suspending said central conductor within said axially aligned first and second outer housings and in insulated relationship therewith;
• said backup welding ring comprising a cylindrical ring having a relatively short axial length in comparison to the length of said first and second outer housings and having an enlarged central diameter region axially aligned with said spaced ends of said first and second housings and in contact with the inner diameter of said weld bead, and having first and second end portions which extend axially outward in opposite directions from said enlarged central diameter region and which are respectively disposed within the interior of said first and second housings and which are respectively adjacent said ends of said first and second housings;
• said first and second end portions of said backup welding ring having identical outer diameters which are radially spaced from the respective surrounding interior diameters of said first and second housings;
• said first and second compressible contamination seals respectively secured to and surrounding said backup welding ring first and second end portions and being disposed in respective spaced planes which are perpendicular to the axis of said backup welding ring, and being compressed in the annular spaces between the inner surface of said first and second housings, respectively, and the opposing outer surfaces of said first and second end portions of said backup welding ring;
• said first and second compressible contamination seals each being axially spaced from said weld bead.