GB2557004A

GB2557004A - Undersea hydraulic coupling with multiple pressure-energized metal seals

Info

Publication number: GB2557004A
Application number: GB1716198.5A
Authority: GB
Inventors: E Smith Robert; Stolle Scott; Roy Chris
Original assignee: National Coupling Co Inc
Current assignee: National Coupling Co Inc
Priority date: 2016-10-04
Filing date: 2017-10-04
Publication date: 2018-06-13
Anticipated expiration: 2037-10-04
Also published as: DE102017217604A1; GB2557004B; GB201716198D0

Abstract

A female hydraulic coupling member 100 has a generally cylindrical body 110 with a central axial bore, and a receiving chamber in the central axial bore for receiving the probe 270 of a corresponding male hydraulic coupling member. It is equipped with a plurality of pressure-energized C-seals 180,181configured to seal between the body and the probe in response to hydrostatic pressure and/or hydraulic fluid pressure. The C-seals may be made from metal. In one aspect, the C-seals are separated by an annular spacer 192 having a generally T-shaped cross section with a portion of the annular spacer projecting into an internal cavity of a C-seal. In another aspect the annular spacer 191 is ring shaped having a generally rectangular cross-section. A seal assembly for a female hydraulic coupling member comprises a metal C-seal having an internal cavity and an annular, axial opening into the internal cavity, and a ring shaped metal C-seal support having an axial projection sized to project into the internal cavity.

Description

(54) Title of the Invention: Undersea hydraulic coupling with multiple pressure-energized metal seals Abstract Title: Female hydraulic coupling member and seal assembly (57) A female hydraulic coupling member 100 has a generally cylindrical body 110 with a central axial bore, and a receiving chamber in the central axial bore for receiving the probe 270 of a corresponding male hydraulic coupling member. It is equipped with a plurality of pressure-energized C-seals 180,181 configured to seal between the body and the probe in response to hydrostatic pressure and/or hydraulic fluid pressure. The C-seals may be made from metal. In one aspect, the C-seals are separated by an annular spacer 192 having a generally T-shaped cross section with a portion of the annular spacer projecting into an internal cavity of a C-seal. In another aspect the annular spacer 191 is ring shaped having a generally rectangular cross-section. A seal assembly for a female hydraulic coupling member comprises a metal C-seal having an internal cavity and an annular, axial opening into the internal cavity, and a ring shaped metal C-seal support having an axial projection sized to project into the internal cavity.

At least one drawing originally filed was informal and the print reproduced here is taken from a later filed formal copy.

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Undersea Hydraulic Coupling with Multiple Pressure-Energized Metal Seals

Cross-Reference to Related Applications:

[0001] This application claims the benefit of U.S. Provisional Application No. 62/404,043 filed on October 4, 2016, the contents of which are hereby incorporated by reference in their entirety.

Statement Regarding Federally Sponsored Research or Development: None

BACKGROUND OF THE INVENTION

Field of the Invention [0002] This invention relates to hydraulic coupling members. More particularly, it relates to subsea hydraulic couplings having pressure-energized metal seals.

Description of the Related Art [0003] A wide variety of undersea hydraulic couplings are available. Some couplings employ metal seals. Examples of undersea hydraulic couplings having metal seals include: U.S. Patent No. 4,694,859 for “Undersea hydraulic coupling and metal seal;” U.S. Patent No. 4,817,668 for “Integral metal seal for hydraulic coupling;” U.S. Patent No. 4,884,584 for “Internally preloaded metalto-metal seal hydraulic connector;” U.S. Patent No. 5,029,613 for “Hydraulic coupler with radial metal seal;” U.S. Patent Nos. 5,099,882 and 5,203,374 for “Pressure balanced hydraulic coupling with metal seals;” U.S. Patent No. 5,284,183 for “Hydraulic coupler with radial metal seal;” U.S. Patent No. 5,339,861 for “Hydraulic coupling with hollow metal O-ring seal;” U.S. Patent No. 5,355,909 for “Undersea hydraulic coupling with metal seals;” U.S. Patent No. 5,979,499 for “Undersea hydraulic coupling with hollow metal seal;” U.S. Patent No. 6,962,347 for “Metal backup seal for undersea hydraulic coupling;” U.S. Patent No. 7,021,677 for “Seal retainer with metal seal members for undersea hydraulic coupling;” U.S. Patent No. 7,303,194 for “Seal retainer with pressure energized metal seal members for undersea hydraulic coupling;” and, U.S. Patent No. 7,810,785 for “Undersea hydraulic coupling with hydrostatic pressure energized metal seal,” all to Robert E. Smith III and assigned to National Coupling Company (Stafford, Texas).

[0004] Other undersea hydraulic couplings employ only “soft seals” - i.e., nonmetal seals that are typically formed of an elastomeric polymer (“elastomer”) or an engineering plastic capable of being machined such as polyetheretherketone (“PEEK”) or DELRIN® acetal resin [E. I. DU PONT DE NEMOURS AND COMPANY, 1007 MARKET ST., WILMINGTON, DELAWARE], [0005] U.S. Patent No. 6,179,002 discloses an undersea hydraulic coupling having a radial pressure-energized seal with a dovetail interfit with the coupling body. The seal has a pair of flexible sealing surfaces for sealing with the male and female coupling members and a cavity therebetween that is exposed to fluid pressure in the coupling. The outer circumference of the seal has a dovetail interfit between inclined shoulders in the female member bore and on a seal retainer that holds the seal in the bore.

[0006] U.S. Patent No. 6,575,430 discloses an undersea hydraulic coupling member having a ring-shaped seal with multiple sealing surfaces extending radially inwardly therefrom. The multiple sealing surfaces help guide the probe of the male coupling member into the female member without the risk of drag or galling of the receiving chamber. The seal has an interfit with reverse inclined shoulders in the female member to restrain the seal from moving radially inwardly due to vacuum or low pressure. Attention is invited in particular to the embodiments shown in Figures 8 and 9 of this patent.

[0007] U.S. Patent No. 6,923,476 discloses a floating seal for an undersea hydraulic coupling member that is moveable radially to seal with the male coupling member even if there is some misalignment with the female coupling member. The floating seal is restricted from axial movement within the female coupling member receiving chamber. The floating seal may seal with the female coupling member.

[0008] U.S. Patent No. 7,575,256 discloses an undersea hydraulic coupling member having a bore liner that protects the coupling members from galling during assembly or disassembly. The bore liner is removable from the bore of a female undersea hydraulic coupling member. The bore liner may be integral with a seal section that may seal with a male undersea hydraulic coupling member. The bore liner also may have an outer diameter configured to engage and interlock with the bore in which the bore liner is positioned. In certain embodiments, the bore liner is fabricated from PEEK.

[0009] U.S. Patent No. 7,163,190 discloses an undersea hydraulic coupling member having a seal retainer with a first inner ring and a second outer ring. The first inner ring and second outer ring are concentric, at least part of the first inner ring inserted through the second outer ring. The second outer ring is threaded to the coupling member to provide sufficient torque to reduce or eliminate any gap between the seal retainer and the shoulder surface in the coupling member on which an elastomeric seal is positioned. Another elastomeric seal is held between the first inner ring and second outer ring of the seal retainer.

[0010] U.S. Patent Nos. 6,983,940 and 7,201,381 to Hailing are directed to a resilient, annular, metallic seal member having a generally J-shaped crosssection. The annular, metallic seal member includes a first end portion having a first distal end, a generally curled second end portion that extends to a second distal end, and a central body portion between and contiguous with the first and second end portions. The annular, metallic seal member has a first side and an opposite second side. The second end portion curls in a first direction in accordance with a predetermined radius such that the second, distal end is located across from the first side of the annular, metallic seal member and the first and second distal ends do not face each other.

BRIEF SUMMARY OF THE INVENTION [0011] A female undersea hydraulic coupling member is equipped with multiple pressure-energized metal seals configured to seal between the body of the female member and the probe of a corresponding male hydraulic coupling member inserted in the receiving chamber of the female member. The sealing effectiveness of the seal may increase in response to fluid pressure which may be internal hydraulic fluid pressure or ambient hydrostatic pressure.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) [0012] FIG. 1 is a cross-sectional view of a female hydraulic coupling member according to one embodiment of the invention.

[0013] FIG. 2 is a cross-sectional view of the female hydraulic coupling member illustrated in FIG. 1 shown engaged with a corresponding male hydraulic coupling member.

[0014] FIG. 2A is an enlarged view of the portion indicated in FIG. 2.

[0015] FIG. 2B is an enlarged view of the portion indicated in FIG. 2 showing an alternative form of seal spacers between the pressure-energized metal seals. [0016] FIG. 3A is a partial cross-sectional view of a female hydraulic coupling member according to an embodiment of the invention having dual pressureenergized metal seals on the seal cartridge and both radial and annular O-ring seals on a split seal retainer.

[0017] FIG. 3B is a partial cross-sectional view of a female hydraulic coupling member according to an embodiment of the invention having back-to-back pressure-energized metal probe seals and both radial and annular O-ring seals on a split seal retainer.

[0018] FIG. 3C is a partial cross-sectional view of a female hydraulic coupling member according to an embodiment of the invention having pressure-energized metal seals at opposite corners of the seal retainer and a pressure-energized metal probe seal.

[0019] FIG. 4A illustrates an alternative embodiment of the female hydraulic coupling member shown in FIG. 3A.

[0020] FIG. 4B illustrates an alternative embodiment of the female hydraulic coupling member shown in FIG. 3B.

[0021] FIG. 4C illustrates an alternative embodiment of the female hydraulic coupling member shown in FIG. 3C.

[0022] FIG. 5A is a partial cross-sectional view of a female hydraulic coupling member according to an embodiment of the invention having a two-piece seal retainer with a radial O-ring seal and back-to-back, pressure-energized metal probe seals.

[0023] FIG. 5B is a partial cross-sectional view of a female hydraulic coupling member according to an embodiment of the invention having a two-piece seal retainer with a corner O-ring seal and back-to-back, pressure-energized metal probe seals.

[0024] FIG. 5C is a partial cross-sectional view of a female hydraulic coupling member according to an embodiment of the invention having a two-piece seal retainer with an annular O-ring face seal and back-to-back, pressure-energized metal probe seals.

[0025] FIG. 6A is a partial cross-sectional view of a female hydraulic coupling member according to an embodiment of the invention having a three-piece seal retainer and both a hydrostatic pressure-energized metal probe seal and a hydraulic fluid pressure-energized metal probe seal.

[0026] FIG. 6B is an illustration of an alternative embodiment of the female hydraulic coupling member shown in FIG. 6A.

[0027] FIG. 6C is an enlargement of the portion indicated in FIG. 6B.

[0028] FIG. 7A is a partial cross-sectional view of a female hydraulic coupling member according to an embodiment of the invention having a two-piece seal retainer with a radial O-ring seal and back-to-back, pressure-energized metal probe seals.

[0029] FIG. 7B is an illustration of an alternative embodiment of the female hydraulic coupling member shown in FIG. 7A.

[0030] FIG. 7C is an enlargement of the portion indicated in FIG. 7B.

[0031] FIG. 8A is a partial cross-sectional view of a female hydraulic coupling member according to an embodiment of the invention having a three-piece seal retainer with a corner-mounted O-ring seal and both a hydrostatic pressureenergized metal probe seal and a hydraulic fluid pressure-energized metal probe seal.

[0032] FIG. 8B is a partial cross-sectional view of a female hydraulic coupling member according to an embodiment of the invention having a three-piece seal retainer with a radial O-ring seal and both a hydrostatic pressure-energized metal probe seal and a hydraulic fluid pressure-energized metal probe seal. [0033] FIG. 8C is an illustration of an alternative embodiment of the female hydraulic coupling member shown in FIG. 8B.

[0034] FIG. 9 contains top plan and cross-sectional views (with dimensions shown in inches) of an alternative embodiment of the seal assembly shown in FIG. 2A.

[0035] FIG. 10 is a cross-sectional view of a female hydraulic coupling member with a seal assembly according to FIG. 9 retained in the receiving chamber with a seal cartridge.

[0036] FIG. 11 contains top plan and cross-sectional views (with dimensions shown in inches) of a particular seal assembly according to an embodiment of the invention having three pressure-energized metal seals configured for energization by hydraulic fluid within a coupling member.

[0037] FIG. 12 is a cross-sectional view (with dimensions shown in inches) ofthe seal assembly of FIG. 11 installed in a female hydraulic coupling member with the probe of a corresponding male hydraulic coupling member inserted therein. [0038] FIG. 13 is a cross-sectional view of a female hydraulic coupling member with a seal assembly according to FIG. 11 retained in the receiving chamber with a seal cartridge.

[0039] FIG. 14 contains top plan and cross-sectional views (with dimensions shown in inches) of a representative metal C-seal of the prior art.

DETAILED DESCRIPTION OF THE INVENTION [0040] The invention may best be understood by reference to various illustrative embodiments of the invention. In the illustrated embodiments, the two least significant digits of the figure element numbers are used to denote similar or corresponding elements.

[0041] FIG. 1 shows an illustrative example of a female hydraulic coupling member 100 according to one embodiment of the invention. FIG. 2 shows the same female hydraulic coupling member with the probe section of a corresponding male hydraulic coupling member 200 seated in the receiving chamber of female member 100.

[0042] Female hydraulic coupling member 100 comprises generally cylindrical body 110 which may have one or more wrench flats (not shown) on its external surface for engaging a tool for rotating body 110 about its longitudinal axis (or for preventing the rotation of body 110 about its longitudinal axis when a hydraulic line is connected thereto at internally threaded connection portion 117 of central axial bore 114).

[0043] Keeper 119 in external circumferential groove 118 may be provided to secure female coupling member 100 in manifold plate 115.

[0044] Optional poppet valve 120 may seal against frusto-conical poppet valve seat 132 in central axial bore 114 with poppet seal 121 which is urged into sealing engagement with frusto-conical poppet valve seat 132 by poppet spring 122 acting against poppet spring seat 124 which may be secured in central axial bore with keeper 126 in a groove in the wall of central axial bore 114. Optional poppet valve 120 may be moved to the open position by axial force acting on poppet actuator 128. Poppet valve 120 is illustrated in the open position in FIG. 2 wherein male poppet valve actuator 188 has moved female poppet valve actuator 128 in the upward direction in FIG. 2.

[0045] Body 110 has a central, axial bore 114 which may have a varying internal diameter. One end of the central axial bore 114 may comprise internallythreaded connector 117 for attaching the female coupling to a hydraulic line, conduit, pipe nipple or the like. Various means well known in the art (such as external circumferential groove 118) may be provided for mounting the female coupling member in a manifold plate or the like.

[0046] Also shown in FIG. 2 is corresponding male hydraulic coupling member 200 which comprises generally cylindrical body 270 which may have one or more wrench flats (not shown) on its external surface for engaging a tool for rotating body 270 about its longitudinal axis.

[0047] Body 270 has a central, axial bore 274 which may have a varying internal diameter.

[0048] One end of male body 270 comprises male probe 271 of reduced external diameter for insertion into the receiving chamber of the female hydraulic coupling member. In the embodiment shown in FIG. 2, probe 71 is provided with anti-fouling flow ports 290 in its side wall. It is common for undersea male hydraulic coupling members to be mounted in a vertical orientation and it has been found that if radial flow ports are provided on the male probe which are angled in the downward direction, the male coupling member is less likely to become fouled by marine sediment falling towards the seafloor. In order to accommodate a male member having such anti-fouling flow ports, bore 114 of the female member may include annular flow channel 130. It will be appreciated, however, that the invention may also be used with coupling members designed for conventional male probes having axial flow ports.

[0049] To provide a fluid-tight seal between the probe 271 of male member 200 and the receiving chamber of the female member 100, the female member may comprise a plurality of sealing elements. The illustrated embodiment comprises a seal cartridge which contains a number of seals and acts to retain other seals in the body of the female hydraulic coupling member. The seal cartridge may comprise a generally cylindrical sleeve 150 which is at least partially inserted into outer shell 154 which has an externally-threaded portion for engaging the bore 114 of female body 110. Sleeve 150 and shell 154 may have an interference fit such that withdrawal of shell 154 from body 110 effects removal of the entire seal cartridge. Spanner engagement holes 156 may be provided in shell 154 to allow an appropriate tool to be used to insert and/or remove the seal cartridge (comprised of elements 150, 152 and 154) as a unit.

[0050] Sleeve 150 may have angled shoulder 160 for engaging crown seal 152 which may have a correspondingly angled end to resist radial movement into the receiving chamber under the influence of negative pressure such as may occur during withdrawal of the male probe. Outer shell 154 of the seal cartridge may have angled shoulder 161 to likewise engage the opposing end of crown seal 152.

[0051] In the embodiment illustrated in FIGS. 1 and 2, probe seal 152 is a double crown seal and includes optional circumferential O-ring seals 148 for sealing between crown seal 152 and seal cartridge sleeve 150. In one particular preferred embodiment, crown seal 152 is machined from polyetheretherketone (PEEK) polymer which has been found to provide sealing effectiveness between the probe sections of male hydraulic coupling members and the receiving chambers of female hydraulic coupling members. Other materials suitable for probe seals are well-known in the art.

[0052] In the embodiment illustrated in FIGS. 1 and 2, sections of differing inside diameter (i.d.) within central axial bore 114 are divided by internal shoulders 134, 135, and 136.

[0053] Pressure-energized metal C-seals 180 and 181 are retained on internal shoulder 136 and provide a seal between the body of the female coupling member and the probe of a male coupling member inserted into the receiving chamber of the female member. Shoulder spacer 195 has a first end which bears against internal shoulder 136 and an opposing second end having projection 197 which fits within, supports, and retains the innermost metal C-seal 180. The end of projection 197 which fits within the C-seal may be rounded to conform to the curvature of the wall of hollow metal C-seal 180. Pressureenergized metal seal supports 192 have a generally T-shaped cross section with the leg of the T forming a projection similar to projection 197 on shoulder spacer 195. The distal end of the projection may be rounded to conform to the curvature of the wall of hollow metal C-seal 180. Spacer ring 191 may be used to separate back-to-back C-seals 180 and 181. As illustrated, a plurality of pressure-energized metal C-seals 181 may be separated and supported on Tshaped, pressure-energized metal seal supports 192. Metal seal supports 192, spacer rings 191, and shoulder spacers 195 may be fabricated of INCONEL® alloy 718 [HUNTINGTON ALLOYS CORPORATION, 3200 RIVERSIDE DRIVE, HUNTINGTON, WEST VIRGINIA 25705] or any other suitable material and, in certain embodiments, may be plated (e.g. gold plated) to reduce galling.

[0054] In the embodiment illustrated in FIGS. 1 and 2, pressure-energized metal C-seals 180 are oriented so as to be energized by hydraulic fluid pressure within the coupling member. Pressure-energized metal C-seals 181 are oriented so as to be energized by hydrostatic fluid pressure from outside the coupling member. It will be appreciated by those skilled in the art that C-seals 180 and 181 may be orientated as desired to provide increased sealing effectiveness for either internal hydraulic fluid or seawater. Subject only to space limitations within the body of the female coupling member, there may be any number of hydraulic fluid-energized C-seals and any number of hydrostatic head-energized C-seals. [0055] Pressure-energized metal C-seals 184 and 185 are retained on internal shoulder 135 and provide a seal between the body of the female coupling member and sleeve 150 of the seal cartridge. Pressure-energized C-seal supports 193 have a generally T-shaped cross section with the leg of the T forming a projection 197' which fits within, supports, and retains metal C-seal 184 or 185 as the case may be. The distal end of the projection may be rounded to conform to the curvature of the wall of hollow metal C-seal 184 or 185. Spacer ring 194 may be used to separate back-to-back C-seals 184 and 185. As illustrated, a plurality of pressure-energized metal C-seals 184 and/or 185 may be separated and supported on T-shaped, pressure-energized metal seal supports 193.

[0056] In the embodiment illustrated in FIGS. 1 and 2, pressure-energized metal C-seal 184 is oriented so as to be energized by hydraulic fluid pressure within the coupling member. Pressure-energized metal C-seals 185 are oriented so as to be energized by hydrostatic fluid pressure from outside the coupling member. It will be appreciated by those skilled in the art that C-seals 184 and 185 may be orientated as desired to provide increased sealing effectiveness for either internal hydraulic fluid or seawater. Subject only to space limitations within the body of the female coupling member, there may be any number of hydraulic fluid-energized C-seals and any number of hydrostatic head-energized C-seals. [0057] An alternative embodiment having different spacers for the pressureenergized metal C-seals is illustrated in FIG. 2B. Shoulder spacer 195' and spacer rings (smaller i.d.) 191 and spacer rings (larger i.d.) 194 are generally rectangular in cross section and do not have the projections 197 of shoulder spacer 195 and T-shaped pressure-energized C-seal supports 192 and 193 that extend into the internal cavity of hollow metal C-seals 180, 181, 184 and 185. [0058] Spacer ring (smaller i.d.) 191, T-shaped pressure-energized metal seal supports (smaller o.d.) 192, T-shaped pressure-energized metal seal supports (larger o.d.) 193, spacer ring (larger i.d.) 194, and shoulder spacer 195 may be made of any suitable material. Examples of suitable materials include metal (which may be a metal softer than the metal of the male probe member so as to prevent galling), polymers, and engineering plastics such as PEEK and DELRIN® [E. I. DU PONT DE NEMOURS AND COMPANY, WILMINGTON, DELAWARE], [0059] For clarity of illustration, the pressure energized metal C-seals shown in the illustrated embodiments are semi-circular in cross section. It should be understood that hollow, pressure-energized metal C-seals having cross sections of more than 180 degrees are commercially available and may be substituted for the “half-circle” C-seals shown in the drawing figures. Various suitable pressureenergized metal C-seals are available from American Seal and Engineering Company, Inc. (Orange, Connecticut).

[0060] FIG. 3A illustrates an embodiment of the invention having a crown seal 352 retained by an inner seal retainer 344 and an outer seal retainer which is a part of a seal cartridge comprised of outer shell 354 which has an interference fit with outer seal retainer 345. O-ring face seals 362 are provided in concentric annular grooves on the inner end of inner seal retainer 344. O-ring seal 340' is provided in a circumferential groove in the outer wall of inner seal retainer 344. O-ring seal 340 is provided in a circumferential groove in the outer wall of outer seal retainer 345. Inner seal retainer 344 has angled shoulder 360 and outer seal retainer 345 has angled shoulder 361 which engage corresponding angled ends of crown seal 352 so as to provide a dovetail interfit that resists implosion of crown seal 352 in negative-pressure situations such as may occur upon withdrawal of the male probe from the receiving chamber of female coupling member 300.

[0061] Pressure-energized metal C-seal 380 is retained on internal shoulder 335 by inner seal retainer 344. Pressure-energized metal C-seal 380 provides a seal between the male probe member and body 310 of female member 300 that is energized by internal hydraulic fluid pressure.

[0062] Pressure-energized metal C-seal 381 is retained on shoulder 336 of outer seal retainer 345 by outer cartridge 354. Pressure-energized metal C-seal 380 provides a seal between the male probe member and body 310 of female member 300 that is energized by hydrostatic fluid pressure.

[0063] Pressure-energized metal C-seal 385 is retained on shoulder 336 of outer seal retainer 345 by outer cartridge 354. Pressure-energized metal C-seal 385 provides a seal between inner seal retainer 345 and outer shell 354 that is energized by hydrostatic fluid pressure.

[0064] The embodiment illustrated in FIG. 3B is similar to that of FIG. 3A but pressure-energized metal C-seal 385 is replaced with annular O-ring face seal 362' and a single annular O-ring face seal 362 is provided on the inner end of inner seal retainer 344'. Pressure-energized metal C-seals 381 and 381 are provided in back-to-back arrangement on internal shoulder 335' in the central axial bore of body 311. Pressure-energized metal C-seals 380 and 381 are separated by split-ring spacer 396 which may be a metal spacer in an undercut groove in the outer wall of shoulder 335'. Inner and outer seal retainers 344' and 345' are secured by retainer locking member 342.

[0065] Another embodiment of the invention is illustrated in FIG. 3C. This embodiment has one-piece inner seal retainer 346 with an angled internal shoulder and a retainer locking member 342 with a complimentary angled internal shoulder. Dovetail probe seal 338 has an interfit with the angled shoulders on retainer locking member 342 and inner seal retainer 346 that resists implosion of probe seal 338 in negative-pressure situations such as may occur upon withdrawal of the male probe from the receiving chamber of female coupling member 302. Probe seal 338 is described in U.S. Patent No. 5,052,439, the contents of which are hereby incorporated by reference in their entirety.

[0066] Pressure-energized metal C-seals 384 and 384' are provided in grooves at the opposing, outside corners of seal retainer 346 to provide a fluid-tight seal between seal retainer 346 and body 310 of female coupling 302. In the illustrated embodiment, pressure-energized metal C-seals 384 and 384' are both oriented so as to be pressure energized by internal hydraulic fluid pressure. It should be understood that either or both of pressure-energized metal C-seals 384 and 384' may be oriented so as to be pressure-energized by hydrostatic fluid pressure.

[0067] FIGS. 4A, 4B, and 4C illustrate embodiments of the invention that correspond generally to the embodiments illustrated in FIGS. 3A, 3B, and 3C, respectively. In the FIG. 4 embodiments, expansion gaps 472 and 472' are provided to accommodate the expansion in the axial direction (of female hydraulic coupling members 400, 401, and 402) of pressure-energized metal Ciseal 480 and 481, when they are mechanically compressed in the radial direction by contact with the probe of a male hydraulic coupling member inserted in the receiving chamber of the female hydraulic coupling member. Similarly, expansion gaps 472 may be provided to accommodate the expansion in the axial direction (of female hydraulic coupling members 400, 401, and 402) of pressure-energized metal C-seals 484, 484' and 485 when they are mechanically compressed in the radial direction by insertion of seal retainer 446 or the insertion of outer seal retainer 445 into outer shell 454 of the seal cartridge (454 + 445) of female coupling member 400.

[0068] FIGS. 5A, 5B, and 5C illustrate variations on an embodiment of the invention having back-to-back pressure-energized metal C-seals 580 and 581 separated by spacer ring 594 which may be a metal spacer ring. Pressureenergized metal C-seal 580 provides a seal between the probe section of a male coupling member inserted in the receiving chamber of female hydraulic coupling member 500, 501, or 502 and the body 510 of the female coupling member. Pressure-energized metal C-seal 581 provides a seal between the probe section of a male coupling member inserted in the receiving chamber of female hydraulic coupling member 500, 501, or 502 and seal retainer 546. In the illustrated embodiments, pressure-energized metal C-seal 580 is oriented so as to be energized by internal hydraulic fluid pressure and pressure-energized metal Cseal 581 is oriented so as to be energized by the hydrostatic pressure of the seawater. It should be appreciated that pressure-energized metal C-seal 580 and 581 may be independently oriented as desired to provide pressure energization by either internal hydraulic fluid pressure or hydrostatic ambient pressure.

[0069] In FIG. 5A, female hydraulic coupling member 500 has radial O-ring seal 540 in a circumferential groove in the outer wall of seal retainer 546 for providing a seal between seal retainer 546 and body 510.

[0070] In FIG. 5B, female hydraulic coupling member 501 has corner O-ring seal 564 in an outside corner groove in the outer wall of seal retainer 546' for providing a seal between seal retainer 546' and body 510.

[0071] In FIG. 5C, female hydraulic coupling member 502 has O-ring face seal 562 in an annular groove in the bottom end of seal retainer 546 for providing a seal between seal retainer 546 and body 510.

[0072] The embodiment illustrated in FIG. 6A has a two-piece seal retainer comprised of inner seal retainer 644 and outer seal retainer 645 both secured in body 610 of hydraulic coupling member 600 by retainer locking member 642. Angled shoulder 660 on inner seal retainer 644 and angled shoulder 661 on outer seal retainer 645 provide a dovetail interfit for probe seal 638 that resists implosion of probe seal 638 in negative-pressure situations such as may occur upon withdrawal of the male probe from the receiving chamber of female coupling member 600. Annular O-ring face seal 662 seals between inner seal retainer 644 and coupling body 610. Annular O-ring face seal 662' seals between inner seal retainer 644 and outer seal retainer 645. Annular O-ring face seal 662 seals between outer seal retainer 645 and retainer locking member 642.

[0073] Pressure-energized metal C-seal 680 is a probe seal secured on shoulder 635 by inner seal retainer 644. Pressure-energized metal C-seal 681 is a probe seal secured on shoulder 636 on outer sealer retainer 645. In the illustrated embodiment, pressure-energized metal C-seal 680 is oriented so as to be energized by internal hydraulic fluid pressure and pressure-energized metal C-seal 681 is oriented so as to be energized by the hydrostatic pressure of the seawater. It should be appreciated that pressure-energized metal C-seal 680 and 681 may be independently oriented as desired to provide pressure energization by either internal hydraulic fluid pressure or hydrostatic ambient pressure.

[0074] FIGS. 6B and 6C illustrate an alternative embodiment having expansion gaps 672. Expansion gaps 672 and 672' may be provided to accommodate the expansion in the axial direction (of female hydraulic coupling member 601) of pressure-energized metal C-seal 680 and 681, when they are mechanically compressed in the radial direction by contact with the probe of a male hydraulic coupling member inserted in the receiving chamber of female hydraulic coupling member 601. As may best be seen in FIG. 6C, expansion gap 672 may be created by providing a shoulder on the inner end of inner seal retainer 644. In this way, expansion gap 672 may be retrofitted to female coupling member 600. Alternatively, expansion gap 672 may be created by increasing the depth of shoulder 635 in female hydraulic coupling member 600.

[0075] Female hydraulic coupling member 700 shown in FIG. 7A is generally similar to female hydraulic coupling member 600 but has one-piece seal retainer 746 with straight shoulder 736 on the inner end thereof and angled shoulder 760 on the opposing end thereof. Retainer locking member 742 has angled shoulder 761 on its inner end. Angled shoulders 760 and 761 provide a dovetail interfit for probe seal 738 that resists implosion of probe seal 738 in negative-pressure situations such as may occur upon withdrawal of the male probe from the receiving chamber of female coupling member 700. Circumferential O-ring seal 740 provides a seal between seal retainer 746 and body 710 of female hydraulic coupling member 700.

[0076] Back-to-back pressure-energized metal C-seal 780 and 782 are retained on shoulders 735 and 736, respectively, and are separated by spacer ring 794 which may be a metal spacer ring. It should be noted that pressure-energized metal C-seal 782 has a larger outside diameter (o.d.) than pressure-energized metal C-seal 780 due to the greater width of shoulder 736 (as compared to shoulder 735). In the illustrated embodiment, pressure-energized metal C-seal 780 is oriented so as to be energized by internal hydraulic fluid pressure and pressure-energized metal C-seal 782 is oriented so as to be energized by the hydrostatic pressure of the seawater. It should be appreciated that pressureenergized metal C-seals 780 and 782 may be independently oriented as desired to provide pressure energization by either internal hydraulic fluid pressure or hydrostatic ambient pressure.

[0077] An alternative embodiment is shown in FIGS. 7B and 7C. In this embodiment, expansion gaps 772 and 772' are provided to accommodate the expansion in the axial direction (of female hydraulic coupling member 701) of pressure-energized metal C-seal 780 and 782, when they are mechanically compressed in the radial direction by contact with the probe of a male hydraulic coupling member inserted in the receiving chamber of female hydraulic coupling member. Expansion gaps 772 and 772' may be provided by decreasing the axial dimension of spacer ring 794 (to create spacer ring 794'). Alternatively, expansion gaps 772 and 772' may be provided by increasing the depth of shoulder 735 and/or the depth of shoulder 736. As may best be seen in FIG. 7C, the axial ends of spacer ring 794' may be contoured to match the curvatures of pressure-energized metal C-seal 780 and 782. Spacer rings 794 and/or 794' may be provided with a section of larger o.d. that fits against the radial wall of shoulder 736 and an adjoining section of smaller o.d. that fits against the radial wall of shoulder 735. In this way, the axial position of spacer ring 794 within the central axial bore of body 710 may be more precisely controlled.

[0078] FIGS. 8A, 8B, and 8C illustrate an embodiment of the invention having a two-piece seal retainer comprised essentially of inner seal retainer 844 seated on shoulder 834 in the central axial bore of body 810 of female hydraulic coupling member 800 and outer seal retainer 845 both secured in the receiving chamber of female coupling member 800 by retainer locking member 842. Angled shoulder 860 on inner seal retainer 844 and corresponding angled shoulder 861 on outer seal retainer 845 provide a dovetail interfit with the angled ends of probe seal 838 that resists implosion of probe seal 838 in negativepressure situations such as may occur upon withdrawal of the male probe from the receiving chamber of female coupling member 800. Probe seal 838 is described in U.S. Patent No. 5,052,439. In the embodiment of FIG. 8A, corner O-ring 864 is provided to seal between inner seal retainer 844 and coupling body 810. In the embodiments of FIG. 8B and 8C, circumferential O-ring 840' is provided to seal between inner seal retainer 844 and coupling body 810. In the embodiments of FIG. 8A, 8B, and 8C, circumferential O-ring 840 is provided to seal between outer seal retainer 842 and coupling body 810.

[0079] Pressure-energized metal C-seal 880 is retained on shoulder 835 by inner seal retainer 844. Pressure-energized metal C-seal 880 is configured to seal between the probe section of a male hydraulic coupling member inserted in the receiving chamber of female coupling member 800, 801 or 802 and body 810. Pressure-energized metal C-seal 881 is retained on shoulder 836 by retainer locking member 842. Pressure-energized metal C-seal 880 is configured to seal between the probe section of a male hydraulic coupling member inserted in the receiving chamber of female coupling member 800, 801 or 802 and outer seal retainer 845. In the illustrated embodiments of FIGS. 8A, 8B, and 8C, pressure-energized metal C-seal 880 is oriented so as to be energized by hydraulic fluid pressure within the coupling member. Pressure-energized metal C-seal 881 is oriented so as to be energized by hydrostatic fluid pressure from outside the coupling member. It will be appreciated by those skilled in the art that C-seals 880 and 881 may be independently orientated as desired to provide increased sealing effectiveness in response to either internal hydraulic fluid pressure or the hydrostatic head of seawater.

[0080] The embodiment illustrated in FIG. 8C is a variation on the embodiment of FIG. 8B. Expansion gaps 872 and 872' are provided in the embodiment of FIG. 8C to accommodate the expansion in the axial direction (of female hydraulic coupling member 802) of pressure-energized metal C-seals 880 and 881, when they are mechanically compressed in the radial direction by contact with the probe of a male hydraulic coupling member inserted in the receiving chamber of female hydraulic coupling member 802. Expansion gap 872 may be provided by providing a shoulder on the inner end of inner seal retainer 844.

Expansion gap 872' may be provided by either increasing the depth of shoulder 836 or providing a shoulder on the inner end of retainer locking member 842. [0081] FIG. 9 shows an alternative embodiment of the seal assembly shown in FIG. 2A. Seal assembly 901 in the embodiment of FIG. 9 is comprised of shoulder spacer 995, hydraulic fluid pressure-energized metal C-seals 180, hydrostatic pressure-energized metal C-seals 181, metal C-seal supports 992 and 998, and spacer ring 991. As illustrated in FIG. 9, shoulder spacer 995, metal C-seal supports 992 and 998, and spacer ring 991 have beveled surfaces adjacent their innermost surfaces so as to reduce friction during the insertion and withdrawal of a male probe member. The axial end surfaces of shoulder spacer 995, metal C-seal supports 992 and 998, and spacer ring 991 may be contoured to fit the abutting surfaces of metal C-seals 180 and 181. FIG. 10 shows seal assembly 901 installed in female coupling body 910 on internal shoulder 936 and retained thereon by a threaded seal cartridge comprising sleeve 950, crown seal 952, and outer shell 954. O-ring seals (not shown) may be provided in circumferential grooves 948. Sleeve 950 may seal to female coupling body 910 with O-ring seal 985 flanked by backup seals 984.

[0082] FIG. 11 illustrates a seal assembly 1101 having three hydraulic-pressure energized metal C-seals 180. Seal assembly 1101 in the embodiment of FIG. 11 is comprised of shoulder spacer 1195, hydraulic fluid pressure-energized metal C-seals 180, metal C-seal supports 1192 and spacer ring 1194. As illustrated in FIG. 11, shoulder spacer 1195, metal C-seal supports 1192, and spacer ring 1194 have beveled surfaces adjacent their innermost surfaces so as to reduce friction during the insertion and withdrawal of a male probe member. The axial end surfaces of shoulder spacer 1195, metal C-seal supports 1192, and spacer ring 1194 may be contoured to fit the abutting surfaces of metal C-seals 180. FIG. 12 shows seal assembly 1101 in sealing engagement with female body 110 and the outer circumferential surface of male probe 271. FIG. 13 shows seal assembly 1101 installed in female coupling body 1110 on an internal shoulder thereof and retained thereon by a threaded seal cartridge comprising sleeve 1150, crown seal 1152, and outer shell 1154. O-ring seals (not shown) may be provided in circumferential grooves 1148. Sleeve 1150 may seal to female coupling body 1110 with O-ring seal 1162 in an annular groove on the inner face of sleeve 1150.

[0083] FIG. 14 depicts a typical, commercially available metal axial C-seal 180 suitable for use in certain embodiments of the invention. Sector C of the outer surface (and optionally the inner surface) may be gold plated (per AMS 2422 0.001 - 0.0015 inch thick). In the area indicated as sector B, gold plating is optional and may be incomplete. In one particular preferred metal C-seal, the material is Alloy 718 per AMS 5596 (0.010 ± .001 inch thick prior to forming) and the area indicated as sector D (symmetrical, both sides) has a surface finish of 16 microns.

[0084] In this disclosure, the pressure-energized C-seals have been described as metal C-seals inasmuch as those are the high-pressure C-seals that are commercially available as of the filing date hereof. It should be understood that high-pressure C-seals may, in the future, be fabricated from materials other than metal and such non-metal C-seals may be used in the practice of the invention. [0085] Although particular embodiments of the present invention have been shown and described, they are not intended to limit what this patent covers. One skilled in the art will understand that various changes and modifications may be made without departing from the scope of the present invention as literally and equivalently covered by the following claims.

Claims

CLAIMS What is claimed is:

1. A female hydraulic coupling member comprising:

a generally cylindrical body having a central axial bore;

a receiving chamber in the central axial bore for receiving the probe of a corresponding male hydraulic coupling member;

a first pressure-energized C-seal having an internal cavity and positioned to seal between the body and the probe of a corresponding male hydraulic coupling member inserted in the receiving chamber and configured such that the sealing force of the first pressureenergized seal increases with an increase in hydraulic fluid pressure;

a second pressure-energized C-seal having an internal cavity and positioned to seal between the body and the probe of a corresponding male hydraulic coupling member inserted in the receiving chamber and configured such that the sealing force of the second pressure-energized seal increases with an increase in hydraulic fluid pressure; and, an annular spacer having a generally T-shaped cross section separating the first pressure-energized C-seal and the second pressureenergized C-seal with at least a portion of the annular spacer projecting into the internal cavity of the second pressure-energized C-seal.

2. A female hydraulic coupling member as recited in claim 1 wherein the pressure-energized C-seal is a metal seal.

3. A female hydraulic coupling member as recited in claim 2 wherein the pressure-energized metal C-seal is generally tubular with an annular opening into the internal cavity.

4. A subsea female hydraulic coupling member comprising:

a generally cylindrical body having a central axial bore;

a second pressure-energized C-seal having an internal cavity and positioned to seal between the body and the probe of a corresponding male hydraulic coupling member inserted in the receiving chamber and configured such that the sealing force of the second pressure-energized seal increases with an increase in hydrostatic head pressure; and, a ring-shaped annular spacer having a generally rectangular cross section separating the first pressure-energized C-seal and the second pressure-energized C-seal.

5. A female hydraulic coupling member as recited in claim 4 wherein the pressure-energized C-seal is a metal seal.

6. A female hydraulic coupling member as recited in claim 5 wherein the pressure-energized metal C-seal is generally tubular with an annular opening into the internal cavity.

7. A subsea female hydraulic coupling member comprising:

a generally cylindrical body having a central axial bore;

a first pressure-energized C-seal having an internal cavity and positioned to seal between the body and the probe of a corresponding male hydraulic coupling member inserted in the receiving chamber and configured such that the sealing force of the first pressure21 energized seal increases with an increase in hydrostatic head pressure;

a second pressure-energized C-seal having an internal cavity and positioned to seal between the body and the probe of a corresponding male hydraulic coupling member inserted in the receiving chamber and configured such that the sealing force of the second pressure-energized seal increases with an increase in hydrostatic head pressure; and, an annular spacer having a generally T-shaped cross section separating the first pressure-energized C-seal and the second pressureenergized C-seal with at least a portion of the annular spacer projecting into the internal cavity of the first pressure-energized Cseal.

8. A female hydraulic coupling member as recited in claim 7 wherein the pressure-energized C-seal is a metal seal.

9. A female hydraulic coupling member as recited in claim 8 wherein the pressure-energized metal C-seal is generally tubular with an annular opening into the internal cavity.

10. A female hydraulic coupling member comprising:

a generally cylindrical body having a central axial bore;

a second pressure-energized C-seal having an internal cavity and positioned to seal between the body and the probe of a corresponding male hydraulic coupling member inserted in the receiving chamber and configured such that the sealing force of the second pressure-energized seal increases with an increase in hydraulic fluid pressure;

a third pressure-energized C-seal having an internal cavity and positioned to seal between the body and the probe of a corresponding male hydraulic coupling member inserted in the receiving chamber and configured such that the sealing force of the third pressureenergized seal increases with an increase in hydraulic fluid pressure;

a first annular spacer having a generally T-shaped cross section separating the first pressure-energized C-seal and the second pressure-energized C-seal with at least a portion of the annular spacer projecting into the internal cavity of the second pressureenergized C-seal; and a second annular spacer having a generally T-shaped cross section separating the second pressure-energized C-seal and the third pressure-energized C-seal with at least a portion of the annular spacer projecting into the internal cavity of the third pressureenergized C-seal.

11. The female hydraulic coupling member recited in claim 10 further comprising:

an annular spacer on a shoulder in the central axial bore said spacer having an axial projection on one end thereof at least a portion of the annular spacer projecting into the internal cavity of the first pressure-energized C-seal.

12. A seal assembly for a female hydraulic coupling member comprising:

a metal C-seal having an internal cavity and an annular, axial opening into the internal cavity;

a ring-shaped metal C-seal support having an axial projection sized and configured to project into the internal cavity of the metal C-seal.

13. The seal assembly recited in claim 12 wherein a distal end of the axial projection is a convex surface having a radius of curvature that is about the same as the radius of curvature of an inside surface of the internal cavity of the metal C-seal.

5

14. The seal assembly recited in claim 12 wherein the end of the ring-shaped metal C-seal support opposite the axial projection has a concave surface having a radius of curvature that is about the same as the radius of curvature of an outer surface of the metal C-seal that is opposite the annular, axial opening into the internal cavity.

10

15. A subsea female hydraulic coupling member comprising:

a generally cylindrical body having a central axial bore;

16. The seal assembly of claim 14, wherein the end of the ring-shaped metal C-seal support opposite the axial projection has a concave surface having a radius of curvature that is about the same as the radius of curvature of an outer surface of the metal C-seal that is opposite the annular, axial opening into the internal cavity.

d o

co

Intellectual

Property

Office

Application No: GB1716198.5 Examiner: Kris Wojciechowski

16. A female hydraulic coupling member comprising:

15 a generally cylindrical body having a central axial bore;

a first pressure-energized C-seal having an internal cavity and positioned to seal between the body and the probe of a corresponding male

20 hydraulic coupling member inserted in the receiving chamber and configured such that the sealing force of the first pressureenergized seal increases with an increase in hydraulic fluid pressure;

a second pressure-energized C-seal having an internal cavity and

25 positioned to seal between the body and the probe of a corresponding male hydraulic coupling member inserted in the receiving chamber and configured such that the sealing force of the second pressure-energized seal increases with an increase in hydraulic fluid pressure;

a first annular spacer having a generally T-shaped cross section separating the first pressure-energized C-seal and the second pressure-energized C-seal with at least a portion of the annular spacer projecting into the internal cavity of the second pressureenergized C-seal;

a third pressure-energized C-seal having an internal cavity and positioned to seal between the body and the probe of a corresponding male hydraulic coupling member inserted in the receiving chamber and configured such that the sealing force of the first pressureenergized seal increases with an increase in hydrostatic pressure;

a fourth pressure-energized C-seal having an internal cavity and positioned to seal between the body and the probe of a corresponding male hydraulic coupling member inserted in the receiving chamber and configured such that the sealing force of the second pressure-energized seal increases with an increase in hydraulic fluid pressure;

a second annular spacer having a generally T-shaped cross section separating the third pressure-energized C-seal and the fourth pressure-energized C-seal with at least a portion of the annular spacer projecting into the internal cavity of the fourth pressureenergized C-seal; and a ring-shaped annular spacer having a generally rectangular cross section separating the third pressure-energized C-seal and the second pressure-energized C-seal.

1604 18

Amendments to the claims have been filed as follows:

1. A female hydraulic coupling member comprising:

a generally cylindrical body having a central axial bore;

a first pressure-energized C-seal having an internal cavity and positioned to seal between the body and the probe of a corresponding male hydraulic coupling member inserted in the receiving chamber and configured such that the sealing force of the first pressure-energized seal increases with an increase in fluid pressure;

a second pressure-energized C-seal having an internal cavity and positioned to seal between the body and the probe of a corresponding male hydraulic coupling member inserted in the receiving chamber and configured such that the sealing force of the second pressure-energized seal increases with an increase in fluid pressure; and an annular spacer having a generally T-shaped cross section separating the first pressure-energized C-seal and the second pressure-energized C-seal with at least a portion of the annular spacer projecting into the internal cavity of the first or second pressure-energized C-seal.

2. The female hydraulic coupling member of claim 1, wherein each of said increase in fluid pressure is an increase in either hydraulic fluid pressure or hydrostatic pressure.

3. The female hydraulic coupling member of claim 1, wherein the first pressure-energized C-seal is configured such that the sealing force of the first pressure-energized seal increases with an increase in hydraulic fluid pressure;

1604 18 wherein the second pressure-energized C-seal is configured such that the sealing force of the second pressure-energized seal increases with an increase in hydraulic fluid pressure; and wherein said at least a portion of the annular spacer projects into the internal cavity of the second pressure-energized C-seal.

4. The female hydraulic coupling member of claim 1, wherein the first pressure-energized C-seal is configured such that the sealing force of the first pressure-energized seal increases with an increase in hydrostatic pressure;

wherein the second pressure-energized C-seal is configured such that the sealing force of the second pressure-energized seal increases with an increase in hydrostatic pressure; and wherein said at least a portion of the annular spacer projects into the internal cavity of the first pressure-energized C-seal.

5. The female hydraulic coupling of claim 3, further comprising:

a third pressure-energized C-seal having an internal cavity and positioned to seal between the body and the probe of a corresponding male hydraulic coupling member inserted in the receiving chamber and configured such that the sealing force of the third pressure-energized seal increases with an increase in hydraulic fluid pressure; and a second annular spacer having a generally T-shaped cross section separating the second pressure-energized C-seal and the third pressure-energized Cseal with at least a portion of the annular spacer projecting into the internal cavity of the third pressure-energized C-seal.

6. The female hydraulic coupling member of claim 5, further comprising:

1604 18

7. The female hydraulic coupling member of claim 3, further comprising:

a third pressure-energized C-seal having an internal cavity and positioned to seal between the body and the probe of a corresponding male hydraulic coupling member inserted in the receiving chamber and configured such that the sealing force of the third pressure-energized seal increases with an increase in hydrostatic pressure;

a fourth pressure-energized C-seal having an internal cavity and positioned to seal between the body and the probe of a corresponding male hydraulic coupling member inserted in the receiving chamber and configured such that the sealing force of the fourth pressure-energized seal increases with an increase in hydrostatic pressure;

a second annular spacer having a generally T-shaped cross section separating the third pressure-energized C-seal and the fourth pressure-energized Cseal with at least a portion of the annular spacer projecting into the internal cavity of the third pressure-energized C-seal; and a ring-shaped annular spacer having a generally rectangular cross section separating the second pressure-energized C-seal and the third pressureenergized C-seal.

8. The female hydraulic coupling member of any preceding claim, wherein a distal end of said projecting portion of at least one of said T-shaped annular spacer is rounded to conform to the curvature of an inside surface of the internal cavity of the C-seal.

9. A female hydraulic coupling member comprising:

a generally cylindrical body having a central axial bore;

a first pressure-energized C-seal having an internal cavity and positioned to seal between the body and the probe of a corresponding male hydraulic coupling member inserted in the receiving chamber and configured such

1604 18 that the sealing force of the first pressure-energized seal increases with an increase in hydraulic fluid pressure;

a second pressure-energized C-seal having an internal cavity and positioned to seal between the body and the probe of a corresponding male hydraulic coupling member inserted in the receiving chamber and configured such that the sealing force of the second pressure-energized seal increases with an increase in hydrostatic pressure; and a ring-shaped annular spacer having a generally rectangular cross section separating the first pressure-energized C-seal and the second pressureenergized C-seal.

10. The female hydraulic coupling of any preceding claim, wherein at least the first and second pressure-energized C-seals are provided in a back-to-back arrangement.

11. The female hydraulic coupling member of any preceding claim, wherein the first and second pressure-energized C-seals are metal seals.

12. The female hydraulic coupling member of claim 11, wherein the pressureenergized metal C-seals are generally tubular with an annular opening into the internal cavity.

13. The female hydraulic coupling member of any preceding claim adapted for subsea use.

14. A seal assembly for a female hydraulic coupling member comprising:

15. The seal assembly of claim 14, wherein a distal end of the axial projection is a convex surface having a radius of curvature that is about the same as the radius of curvature of an inside surface of the internal cavity of the metal C-seal.