Patent ID: 7976074

Claim:
An isolation system that provides an interface between joined flange pieces, each having an inner and an outer face, in a flow line that is operative for fluid passage therethrough, comprising: a flat metal gasket having an opening formed therein to allow fluid passage therethrough, said flat metal gasket having opposing side surfaces each having a layer of dielectric material thereon, each of said opposing side surfaces having an inner groove and an outer groove, each of said inner and outer grooves extending completely around said opening on each of the side surfaces; a primary seal element disposed in said inner groove on each opposing side surface; a secondary annular metal seal element disposed in said outer groove on each opposing side surface; and a compression limiter disposed in said outer groove on each opposing side surface, the height of said compression limiter substantially corresponding to the depth of said outer groove whereby said annular metal seal is not overcompressed when said layer of dielectric material is reduced; at least one isolating sleeve receivable in an aligned bore formed in each of said joined flange pieces, said sleeve having a length that is substantially equal to a distance between said outer faces of said joined flange pieces with said gasket interposed therebetween; at least one elongate metal fastener having opposing ends, said fastener being receivable in said isolating sleeve for connecting said joined flange pieces to one another with said flat metal gasket interposed therebetween; and at least one isolating washer receivable on at least one elongate metal fastener abutting at least one outer face of said flange pieces; and said compression limiter is disparate from said annular metal seal element and is coated with dielectric material.