Abstract: A conduit coupling includes an improved plug assembly. The plug assembly has a valve which limits excess flow in the direction of normal flow and prevents backflow in the opposite direction. The valve includes a valve member which is operated from a first closed condition to an open condition in response to a pressure differential caused by normal flow. The valve member further moves to a second closed condition in response to a predetermined pressure differential across the valve member which would result in an excess flow in the downstream direction. The valve member operates from its open condition to the first closed condition whenever the difference between the upstream pressure and the downstream pressure is less than a predetermined amount, thus preventing backflow. A leak down passage is provided which allows fluid to flow through the valve assembly even when the valve is closed.

Abstract: There is provided a quick connect-disconnect coupling for simultaneous connection and disconnection of fluid conduits and an electrical conductor. The coupling is characterized by an electrical socket structure carried by a wall across the fluid socket. The electrical socket is constructed and dimensioned for telescopic receipt of a fluid plug member adapted to be lockingly engaged in said fluid socket. The fluid plug member includes a cooperating electrical plug structure recessed within the leading end portion thereof. The fluid plug and the fluid socket members protect the electrical conductor elements in the disconnected condition against damage in handling. A sleeve valve is provided in the coupling to control fluid flow between on and off conditions while the coupling is connected.