Abstract: A high reliability undersea coupling design which employs only metal seals, and in which forces from high internal pressure are balanced so that these pressures do not tend to cause uncoupling.

Abstract: A coupling device for detachably connecting male and female coupling members which serve to provide a fluid connection between a fluid source and an implement operated from the fluid source. Check valves are provided in both of the coupler members and an actuating means is provided for engaging the check valve in the male coupler to insure against closing of the male coupler check valve during fluid flow through the coupling device. A fluid actuated lock means is provided to hold the actuating member in its operative position.

Abstract: A quick disconnect coupling wherein the male coupler part has both threads and a groove so that it can be universally secured to a female coupler part regardless of whether the female coupler part carries a threaded nut or detent type securing or connecting means.

Abstract: A coupling assembly for fluid-flow systems is disclosed which includes both a coupler and a nipple. The mating or sealing surfaces of the coupler and nipple are protected from dirt and other deleterious substances by corresponding moveable covers. The moveable covers not only protect the mating surfaces but present flush faces for the coupler and nipple which are easily cleaned. The construction of the coupling assembly is designed so that connection of the coupler and nipple may be accomplished by using only one hand. The coupler is designed so as to render the adapter and the valve a one-piece structure.

Abstract: A cartridge type check valve which may be either pilot operated or of the free flow type. The pilot operated type includes in combination a generally cylindrically-shaped housing having first and second end portions and having internal wall means defining an opening extending axially therethrough. A valve seat is formed on the internal wall means and a valve member is movable into and out of engagement with the valve seat to selectively prohibit and permit fluid flow through the axially extending opening at the valve seat. A fluid port is provided in the first end portion of the housing and serves to provide for fluid entrance into the axially extending opening. A control piston is positioned in the second end portion of the housing and is movable between first and second positions as is a valve stem, which is connected to the valve member and extends axially to a position adjacent the control piston and is adapted to be engaged and moved by the control piston.