SICHERHEITSVORRICHTUNG ZUM AUTOMATISCHEN SCHLIESSEN HYDRAULISCHER LEITUNGEN EINES UNTERWASSERBOHRLOCH-FUTTERROHRES

An improved safety apparatus for automatically sealing hydraulic lines within a sub-sea well casing when said casing is disconnected from an associated well head connector and Christmas tree assembly, has mandrel means associated with a well head connector assembly and valve means generally coaxially aligned within and to the casing means for controlling fluid flow through associated hydraulic lines, the valve means being moved into a valve-opened position by the mandrel means as the well head connector assembly is landed on the well casing head. Bias means associated with the valve means are provided for urging the valve means into a valve-closed position to seal the hydraulic lines when the mandrel means is withdrawn from the valve means. Hydraulic fluid flow is through passages through the mandrel, the valve means and associated portions of the well head connector and casing head, respectively. Seal means are associated with the valve means to provide a fluid-tight seal between the mandrel means and the valve means and between valve means and the well casing head.