Compound back-up ring for O-ring/back-up ring sealing systems in 70 MPA hydrogen storage systems

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.