# US 9,752,682 B2 · Compound back-up ring for O-ring/back-up ring sealing systems in 70 MPA hydrogen storage systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,752,682 B2 - Document ID: US9752682B2 - Status: Granted - Kind: B2 - Application number: 13/606,150 - Filed: 2012-09-07 - Published: 2014-03-13 - Granted: 2017-09-05 - Earliest claimed: 2012-09-07 - Assignees: GM Global Technology Operations LLC - Applicants: Holger Winkelmann; Stefan Slavik - Inventors: Holger Winkelmann; Stefan Slavik - Web page: https://patentgrep.com/patent/US9752682B2 ## CPC - F16J 15/166: {with means to prevent the extrusion of the packing} - F17C 2209/234: of closing end pieces, e.g. caps - F17C 2221/012: Hydrogen - F17C 2223/0123: gaseous, e.g. CNG, GNC - F17C 2223/036: Very high pressure (>80 bar) - F17C 2260/036: Avoiding leaks - F17C 2270/0184: Fuel cells - F17C 2270/0763: Fuel cells - H01M 8/04208: {Cartridges, cryogenic media or cryogenic reservoirs} - H01M 2250/20: Fuel cells in motive systems, e.g. vehicle, ship, plane - Y02E 60/32: Hydrogen storage - Y02E 60/50: Fuel cells - Y02T 90/40: Application of hydrogen technology to transportation, e.g. using fuel cells - F16J: PISTONS {(specially adapted for dampers F16F9/32)}; CYLINDERS; SEALINGS - F17C: VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES (storing fluids in natural or artificial cavities or chambers in the earth B65G5/00; construction or assembling of bulk storage containers employing civil-engineering techniques E04H7/00; variable-capacity gas-holders F17B; liquefaction or refrigeration machines, plants, or systems F25) - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract O-ring/back-up ring systems that are suitable for use in high pressure applications, including those of 70 MPa automotive hydrogen storage applications, to form a seal between first and second connector bodies. Such sealing systems comprise a back-up ring having a base portion and a flange portion, wherein such ring is configured to prevent extrusion of an O-ring into a gap existing between the back-up ring and a groove into which the back-up ring and O-ring are disposed. High pressure gas storage systems comprising such sealing systems, and methods of sealing a connection in a high pressure hydrogen storage system using such sealing systems. ## Claims ### Claim 1 A high pressure gas storage system for automotive fuel cell applications wherein “high pressure” is defined as comprising operating pressures of at least 35 MPa, the storage system comprising: a first connector body having an outer circumference comprising a groove, the groove comprising (i) a side proximate to a source of high pressure of at least 35 MPa; (ii) an opposing distal side, and (iii) an inner surface disposed therebetween; a second connector body having an inner surface configured to tightly encompass the outer circumference of the first connector body; an O-ring at least partially disposed within the groove; a back-up ring at least partially disposed within the groove, the back-up ring having (i) a base portion comprising (a) a distal face configured to engage the groove distal side; (b) an opposing proximate face having a first segment configured to engage the O-ring; and (c) an inner face; and (ii) a flange portion disposed on the inner and proximate faces, wherein the base portion and the flange portion are constructed of different materials and the flange portion is relatively flexible compared to the base portion; further wherein the opposing proximate face of the base portion includes a second segment contiguous with the first segment, a third segment contiguous with the second segment, and a fourth segment contiguous with the third segment; wherein the flange portion includes a fifth segment configured to directly abut the second segment of the base portion; wherein the flange portion includes a sixth segment configured to directly abut the third segment of the base portion, the sixth segment being contiguous with the fifth segment; wherein the flange portion includes a seventh segment configured to directly abut the fourth segment of the base portion, the seventh segment being contiguous with the sixth segment; wherein the second and fourth segments of the base portion and the fifth and seventh segments of the flange portion are each substantially arcuate; wherein upon exposure to a positive pressure of at least 35 MPa, the back-up ring engages the O-ring to cooperatively form a seal between the first and second connector bodies, the O-ring and the flange portion; and wherein the back-up ring is configured to prevent (i) extrusion of the O-ring into a gap between the outer surface of the first connector body and the inner surface of the second connector body; and (ii) extrusion of the O-ring into a gap between the inner face of the back-up ring and the groove inner surface. ### Claim 2 (depends on 1) The storage system of claim 1, wherein the system is a 35 MPa or 70 MPa hydrogen storage system for fuel cell vehicles. ### Claim 3 (depends on 1) The storage system of claim 1, wherein the O-ring is constructed of a material selected from nitriles, such as acrylonitrile-butadiene, hydrogenated nitrile, and carboylated nitrile; rubbers, such as ethylene propylene diene monomer, ethylene propylene rubber, chloroprene rubber, butyl rubber, and silicone rubber; fluorocarbon; fluorosilicone; perfluoroelastomer; tetrafluoroethylene-propylene; ethylene acrylate; polyacrylate; and thermoplastic polyurethane. ### Claim 4 (depends on 1) The storage system of claim 1, wherein the base portion of the back-up ring is constructed of a material selected from nitriles, poly tetra fluoro ethylene; poly ether ether ketone; ultra-high molecular weight polyethylene; polyurethane; and fluorocarbon. ### Claim 5 (depends on 1) The storage system of claim 1, wherein the flange portion is constructed of a material selected from nitriles, acrylonitrile-butadiene, fluorocarbon, thermoplastic polyurethane, rubber, ethylene propylene rubber, ethylene propylene diene monomer, chloroprene rubber, butyl rubber, and silicone rubber. ### Claim 6 (depends on 1) The storage system of claim 1, wherein the flange portion of the back-up ring is bonded to the base portion of the back-up ring. ### Claim 7 (depends on 1) The storage system of claim 1, wherein the first and second connector bodies are portions of a pressure regulator, an excess flow limiter, a shut-off valve, a check valve, a flow valve, or a pipe fitting. ### Claim 8 (depends on 6) The storage system of claim 6, wherein the flange portion is bonded to the base portion by adhesive, heat, or combinations thereof. ### Claim 9 (depends on 1) The storage system of claim 1, wherein the back-up ring is discontinuous. ### Claim 10 (depends on 1) The storage system of claim 1, wherein a contour of the lip inversely corresponds to a contour of the O-ring such that the lip is a mating surface to the O-ring. ### Claim 11 (depends on 1) The storage system of claim 1, wherein an entire length of the flange portion facing the O-ring abuts the O-ring. ### Claim 12 (depends on 1) The storage system of claim 1, wherein: the first segment of the base portion is substantially parallel to the third segment of the base portion. ### Claim 13 (depends on 1) The storage system of claim 1, wherein: the sixth segment of the flange portion is substantially parallel to the third segment of the base portion. ### Claim 14 (depends on 1) The storage system of claim 1, wherein: the flange portion and the base portion each define a respective inner diameter relative to a center of the back-up ring; and the respective inner diameter of the flange portion is less than the respective inner diameter of the base portion. ### Claim 15 (depends on 1) The storage system of claim 1, wherein: the flange portion includes a lip protruding towards the O-ring, the lip abutting the O-ring at the inner surface of the groove. ### Claim 16 (depends on 15) The storage system of claim 15, wherein: the O-ring is configured to directly face the first segment of the opposing proximate face of the base portion; and the O-ring is configured to directly face the lip of the flange portion.