Energized composite metal to metal seal

A sealing device, comprising:

• at least one metal seal with a generally I-shaped cross-section, the metal seal including at least first and second metal sealing surfaces, the first metal sealing surface facing radially outward, whereby the first metal sealing surface forms a metal to metal seal with an internal cylindrical surface, and the second metal sealing surface facing radially inward, whereby the second metal sealing surface forms a metal to metal seal with an external cylindrical surface;
• a first transverse facing recess of the metal seal, the first recess being positioned between the first and second metal sealing surfaces of the metal seal, wherein the metal seal prevents fluid flow through the sealing device;
• at least a first nonmetal seal received in the first recess, the first nonmetal seal including at least first and second nonmetal sealing surfaces,
• the first nonmetal sealing surface being positioned proximate the first metal sealing surface and facing radially outward, whereby the first nonmetal sealing surface contacts and forms a seal with the internal cylindrical surface, and
• the second nonmetal sealing surface being positioned proximate the second metal sealing surface and facing radially inward, whereby the second nonmetal sealing surface contacts and forms a seal with the external cylindrical surface,
• wherein the first nonmetal seal biases the first metal sealing surface radially outward and biases the second metal sealing surface radially inward when a first pressure differential is applied across the sealing device;
• and
• a second nonmetal seal received in a second transverse facing recess of the metal seal, the second recess being positioned between third and fourth metal sealing surfaces of the metal seal, whereby the third metal sealing surface forms a metal to metal seal with the internal cylindrical surface, and the fourth metal sealing surface forms a metal to metal seal with the external cylindrical surface,
• wherein the second nonmetal seal includes third and fourth nonmetal sealing surfaces, the third nonmetal sealing surface positioned proximate the third metal sealing surface and facing radially outward, whereby the third nonmetal sealing surface contacts and forms a seal with the internal cylindrical surface, and the fourth nonmetal sealing surface being positioned proximate the fourth metal sealing surface and facing radially inward, whereby the fourth nonmetal sealing surface contacts and forms a seal with the external cylindrical surface,
• wherein the second nonmetal seal biases the third metal sealing surface radially outward and biases the fourth metal sealing surface radially inward in response to a second pressure differential across the sealing device, the second pressure differential being in an opposite direction to the first pressure differential, and
• wherein the first nonmetal seal includes a third transverse facing recess which axially overlaps at least a portion of the first recess, and the second nonmetal seal includes a fourth transverse facing recess which axially overlaps at least a portion of the second recess.

A method of sealing between a housing assembly and a closure member, the method comprising:

• providing a sealing device including at least one metal seal and at least first and second nonmetal seals, wherein the metal seal prevents fluid flow through the sealing device, wherein the metal seal has a generally I-shaped cross-section which includes first and second transverse facing recesses, wherein the first and second recesses are bounded by separate pairs of arms extending axially outward from a radially extending central web, wherein the first nonmetal seal is disposed in the first recess of the metal seal and the second nonmetal seal is disposed in the second recess of the metal seal, and
• wherein the first nonmetal seal includes a third transverse facing recess which axially overlaps at least a portion of the first recess, and the second nonmetal seal includes a fourth transverse facing recess which axially overlaps at least a portion of the second recess;
• applying a first pressure differential in a first direction across the sealing device while the sealing device seals between the housing assembly and the closure member, wherein the first pressure differential increases contact pressure in a metal to metal seal between an internal cylindrical surface of the housing assembly and a first metal sealing surface on the metal seal, and increases contact pressure in a metal to metal seal between an external cylindrical surface of the closure member and a second metal sealing surface on the metal seal, wherein the first pressure differential increases contact pressure between the internal cylindrical surface and a first nonmetal sealing surface on the first nonmetal seal, and increases contact pressure between the external cylindrical surface and a second nonmetal sealing surface on the first nonmetal seal;
• and
• applying a second pressure differential in a second direction across the sealing device while the sealing device seals between the housing assembly and the closure member, the second direction being opposite to the first direction, wherein the second pressure differential increases contact pressure in a metal to metal seal between the internal cylindrical surface and a third metal sealing surface on the metal seal, and increases contact pressure in a metal to metal seal between the external cylindrical surface and a fourth metal sealing surface on the metal seal,
• wherein the second pressure differential increases contact pressure between the internal cylindrical surface and a third nonmetal sealing surface on the second nonmetal seal, and increase contact pressure between the external cylindrical surface and a fourth nonmetal sealing surface on the second nonmetal seal.

A sealing device, comprising:

• at least one metal seal including at least first and second metal sealing surfaces, the first metal sealing surface facing radially outward, whereby the first metal sealing surface forms a metal to metal seal with an internal cylindrical surface, and the second metal sealing surface facing radially inward, whereby the second metal sealing surface forms a metal to metal seal with an external cylindrical surface, wherein a first transverse facing recess is positioned between the first and second metal sealing surfaces, and wherein the metal seal prevents fluid flow through the sealing device;
• at least a first nonmetal seal received in the first recess, the first nonmetal seal including at least first and second nonmetal sealing surfaces, the first nonmetal sealing surface being positioned proximate the first metal sealing surface and facing radially outward, and the second nonmetal sealing surface being positioned proximate the second metal sealing surface and facing radially inward, wherein a second transverse facing recess is positioned between the first and second nonmetal sealing surfaces, the second transverse facing recess at least partially axially overlapping the first transverse facing recess;
• a second nonmetal seal which biases a third metal sealing surface radially outward and biases a fourth metal sealing surface radially inward in response to a second pressure differential across the sealing device, the second pressure differential being in an opposite direction to the first pressure differential;
• and
• a first energizing device received in the second recess, wherein the first energizing device biases the first non-metal sealing surface radially outward.