Double-shoulder, double-rail serrated metal gasket

An isolation gasket, comprising:

• a metal core having a first inner diameter and defining:
• an inner serrated annular section that is radially spaced from an outer serrated annular section;
• and
• an annular groove formed between the inner and outer serrated annular sections;
• a first material accommodated in the annular groove;
• a second material coupled to the inner serrated annular section;
• and
• a third material coupled to the outer serrated annular section;
• wherein the second material forms a first annular ring defining a second inner diameter that is less than the first inner diameter;
• and
• wherein a top surface of the first material is coupled to both the second material and the third material.

A method of electrically isolating flanged joints, comprising:

• accommodating a gasket between first and second flanged joints;
• wherein the gasket comprises:
• a metal core having an inner diameter and comprising:
• a top surface forming a first annular serrated portion that is concentrically disposed within a second annular serrated portion, the first annular serrated portion being radially spaced from the second annular serrated portion by a top groove;
• and
• a bottom surface forming a third annular serrated portion that is concentrically disposed within a fourth annular serrated portion, the third annular serrated portion being radially spaced from the fourth annular serrated portion by a bottom groove;
• first and second sealing materials engaging at least a portion of the top surface, the second sealing material being concentrically disposed about an external surface of the first sealing material;
• and
• third and fourth sealing materials engaging at least a portion of the bottom surface, the fourth sealing material being concentrically disposed about an external surface of the third sealing material;
• a first ring disposed within the top groove, wherein a top surface of the first ring is coupled to both the first material and the second material;
• and
• a second ring disposed within the bottom groove, wherein a top surface of the second ring is coupled to both the third material and the fourth material;
• wherein the first sealing material has a first thickness;
• wherein the second sealing material has a second thickness that is less than the first thickness;
• wherein the third sealing material has a third thickness;
• wherein the fourth sealing material has a fourth thickness that is less than the third thickness;
• wherein the first sealing material forms a first annular ring defining a first inner diameter that is less than the inner diameter of the metal core;
• and
• wherein the third sealing material forms a second annular ring defining a second inner diameter that is less than the inner diameter of the metal core;
• and
• compressing the gasket, using the first and second flanged joints, to sealingly engage the first and second sealing materials to the first flange joint and to sealingly engage the third and fourth sealing materials to the second flange joint.