A system for establishing a metal-to-metal seal joining two bores, the system comprising: a generally cylindrical seal having a first end, a second end, an innermost diameter (W1), an outer diameter (W2), and a further outer diameter (W3), a first metallic sealing surface defined by a surface area extending from the innermost diameter (W1) to the outer diameter (W2) at the first end, a second metallic sealing surface defined by a surface area extending from the innermost diameter (W1) to the outer diameter (W2) at the second end, a third metallic sealing surface defined by a surface area extending from the outer diameter (W2) to the further outer diameter (W3) proximate to the first end, and a fourth metallic sealing surface defined by a surface area extending from the outer diameter (W2) to the further outer diameter (W3) proximate to the second end; a first piece of equipment having a bore therethrough, wherein the bore comprises a first inner diameter (R1), a second inner diameter (R2), and a metallic sealing surface between the first and second inner diameters (R1, R2); and a second piece of equipment having a bore therethrough, wherein the bore comprises the first inner diameter (R1), the second inner diameter (R2), and a metallic sealing surface between the first and second inner diameters (R1, R2), wherein the metallic sealing surface of the first piece of equipment abuts the first metallic sealing surface of the seal, the metallic sealing surface of the second piece of equipment abuts the second metallic sealing surface of the seal, and the bores of the first and second pieces of equipment are aligned and joined through the inner diameter of the seal , characterized in that the third and fourth metallic sealing surfaces are arcuate and form a radial bulge extending concentrically from the longitudinal axis of the seal. a generally cylindrical seal having a first end, a second end, an innermost diameter (W1), an outer diameter (W2), and a further outer diameter (W3), a first metallic sealing surface defined by a surface area extending from the innermost diameter (W1) to the outer diameter (W2) at the first end, a second metallic sealing surface defined by a surface area extending from the innermost diameter (W1) to the outer diameter (W2) at the second end, a third metallic sealing surface defined by a surface area extending from the outer diameter (W2) to the further outer diameter (W3) proximate to the first end, and a fourth metallic sealing surface defined by a surface area extending from the outer diameter (W2) to the further outer diameter (W3) proximate to the second end; a first piece of equipment having a bore therethrough, wherein the bore comprises a first inner diameter (R1), a second inner diameter (R2), and a metallic sealing surface between the first and second inner diameters (R1, R2); and a second piece of equipment having a bore therethrough, wherein the bore comprises the first inner diameter (R1), the second inner diameter (R2), and a metallic sealing surface between the first and second inner diameters (R1, R2), wherein the metallic sealing surface of the first piece of equipment abuts the first metallic sealing surface of the seal, the metallic sealing surface of the second piece of equipment abuts the second metallic sealing surface of the seal, and the bores of the first and second pieces of equipment are aligned and joined through the inner diameter of the seal , characterized in that the third and fourth metallic sealing surfaces are arcuate and form a radial bulge extending concentrically from the longitudinal axis of the seal. <EOS>