Abstract: A dummy undersea hydraulic coupling member is disclosed for protecting an opposing undersea hydraulic coupling member when the hydraulic lines are not operating. The dummy undersea hydraulic coupling member has a water displacement expansion chamber with a piston therein that allows trapped water and/or air to move from the receiving chamber to the water displacement expansion chamber during connection of the dummy coupling member to the opposing coupling member.

Abstract: A coupling and metal seal are disclosed, primarily for use in undersea hydraulic applications. The female member of the coupling is of three-piece construction. The main body portion accepts a cylindrical retainer which is held captive within the body by means of a spring clip or snap ring. The metal seal is generally ring-shaped and is positioned within the body and held captive by the retainer and clip. The male member, or probe, of the coupling fits within the retainer and body and protrudes through the ring of the metal seal. The seal engages the circumference of the probe and, when the coupling is pressurized, the seal is urged against the probe circumference and against the interior wall of the body, effectuating a fluid seal within the coupling.

Abstract: An undersea hydraulic coupling including a male member and a female member, each of the members having a poppet valve biased to a closed position. At least one of the members has a bleed passage through the poppet valve and a bleed valve which opens to allow hydraulic fluid at high pressure to escape through the bleed passage until the pressure is below a predetermined amount.

Abstract: A probe member for an undersea hydraulic coupling is disclosed having at least one circumferential depression in its outer cylindrical body, for disengaging one or more radial seals during insertion or withdrawal of the probe member from the receiving member of a coupling. The disengagement of the radial seals allows seawater to bleed from or into the space between the coupling members and thereby balance the coupling and seals to seawater pressure.