Breakaway coupling

Abstract

A breakaway coupling including first and second coupling parts secured together by releasable means, the releasable means permitting separation of the coupling parts in a given direction when exposed to a separating force in excess of a predetermined force in said direction, at least one of the coupling parts including valve means, the valve means being normally retained at an open position and being movable to a closed position when said coupling parts move apart in said direction, the valve means comprising an annular valve seat formed in said one coupling part, a valve element which when seated on the valve seat prevents fluid flow through said one coupling part, the valve element being movably mounted within the coupling part for movement between open and closed positions, the valve element when at said open position being spaced from the valve seat to permit flow of fluid through the coupling part and when at said closed position being seated upon the valve seat to prevent fluid flow through the coupling part, the valve element being pivotally mounted on an elongate support for movement from the open position to an intermediate position whereat it is opposed to said valve seat but spaced therefrom in said given direction, the support extending longitudinally in said given direction and being movable in said given direction between a first position whereat the support locates the valve element at its open position and a second position whereat the support locates the valve element at its closed position, trigger release means for retaining the support at its first position, the valve element being co-operable with the trigger release means to cause release of the support when the valve element moves to its intermediate position to thereby enable the support to move to its second position and the valve element to move to its closed position.