An isolation
gasket for use between joined pieces in a flow line includes, for example, a flat annular
metal plate having an opening formed therethrough with a sheet of
dielectric material laminated to its opposing side surfaces and a groove formed on the opposing side surfaces which penetrates through the
dielectric material and into the
metal plate. Each groove extends completely around the opening in the
gasket, and a layer of insulating material, as well as a seal element, is disposed in each of the grooves. An
isolation system between joined
flange pieces utilizes the isolation
gasket in combination, for example, with an insulating sleeve receivable in an aligned bore of each of the joined
flange pieces, an elongate
metal fastener receivable in the insulating sleeve for connecting the joined
flange pieces with the isolation gasket therebetween. A flat metal
washer with a sheet of
dielectric material laminated to one of its opposing side surfaces is receivable on the elongate metal
fastener with the laminated dielectric material abutting one of the flange piece outer faces, and at least one metal
spring force exerting component is also receivable on the
fastener abutting the flat metal
washer.