Pressure operated safety valve

Claim 1

A WELL TOOL FOR CONTROLLING THE FLOW FLUIDS THROUGH A WELL CONDUCTOR INCLUDING: AN ELONGATE BODY POSITIONABLE IN A WELL FLOW CONDUCTOR AND HAVING A FLOW PASSAGE EXTENDING LONGITUDINALLY THERETHROUGH PROVIDED WITH AN INLET OPENING AND A DISCHARGE OPENING; A BALL VALVE MEMBER ROTATABLY MOUNTED IN THE BODY IN SAID FLOW PASSAGE AND HAVING A FLOW PASSAGE EXTENDING TRANSVERSELY THERETHROUGH; MEANS CONNECTING SAID BALL VALVE MEMBER WITH SAID BODY FOR ROTATIVE MOVEMENT OF SAID BALL VALVE MEMBER IN SAID BODY; AN ELONGATE TUBULAR VALVE SEAT MEMBER SLIDABLY MOUNTED IN THE FLOW PASSAGE OF THE BODY DOWNSTREAM OF THE BALL VALVE MEMBER AND HAVING A LONGITUDINAL FLOW PASSAGE THERETHROUGH, SAID VALVE SEAT MEMBER ENGAGING SAID BALL VALVE MEMBER AND COACTING THEREWITH TO CLOSE OFF FLOW THROUGH SAID BODY WHEN SAIUD VALVE SEAT MEMBER IS DISPOSED IN A FIRST LONGITUDINAL POSITION IN SAID BODY WITH THE FLOW PASSAGE OF SAID SEAT MEMBER OUT OF COMMUNICATION WITH THE FLOW PASSAGE OF THE BALL VALVE MEMBER; VALVE SEAT BIASING MEANS IN SAID BODY BETWEEN SAID VALVE SEAT MEMBER AND SAID VALVE BODY AND SEALED OFF FROM FLUID PRESSURE EXTERIORLY OF SAID BODY AND SEALED OFF FROM SAID BALL VALVE MEMBER AND CONFINED BETWEEN SAID VALVE SEAT MEMBER AND SAID BODY AND BIASING SAID VALVE SEAT MEMBER LONGITUDINALLY IN SAID BODY TOWARD SAID FIRST POSITION IN SAID BODY, SAID BALL VALVE MEMBER ENGAGING SAID VALVE SEAT MEMBER TO CLOSE OFF FLOW THROUGH THE BODY WHEN SAID VALVE SEAT MEMBER IS IN SAID FIRST POSITION; AN ACTUATING MEMBER IN THE BODY FLOW PASSAGE UPSTREAM OF THE BALL VALVE AND ENGAGING THE BALL VALVE ON THE SIDE THEREOF OPPOSITE SAID VALVE SEAT MEMBER; RESILIENT MEANS BIASING SAID ACTUATING MEMBER TOWARD THE BALL VALVE MEMBER TO MOVE SAID BALL VALVE MEMBER LONGITUDINALLY OF SAID BODY WITH RESPECT TO SAID ROTATABLE CONNECTION THEREWITH AND TOWARD SAID VALVE SEAT MEMBER TO MAINTAIN THE BALL VALVE MEMBER IN ENGAGEMENT WITH THE VALVE SEAT MEMBER; AND MEANS ON THE VALVE SEAT MEMBER PROVIDING A PRESSURE SURFACE AREA EXPOSED TO THE PRESURE OF FLUID FLOWING THROUGH THE BODY AND ACTING ON SAID PRESSURE SURFACE AREA FOR MOVING SAID VALVE SEAT MEMBER LONGITUDINALLY OF SAID BODY AGAINST THE FORCE EXERTED ON SAID VALVE SEAT MEMBER BY SAID VALVE SEAT BIASING MEANS TO MOVE THE SEAT MEMBER AND THE BALL VALVE IN THE BODY TOWARD A SECOND LONGITUDINAL POSITION IN THE BODY WHEREIN THE BALL VALVE MEMBER IS DISPOSED IN ENGAGEMENT WITH THE VALVE SEAT MEMBER WITH THE FLOW PASSAGE OF THE BALL VALVE MEMBER IN COMMUNICATION WITH THE FLOW PASSAGE THROUGH THE VALVE SEAT MEMBER TO PERMIT FLUID FLOW THROUGH THE BODY; AND BIASING MEANS ACTING ON SAID VALVE SEAT MEMBER NORMALLY BIASING SAID VALVE SEAT MEMBER TO SAID FIRST POSITION WHEREIN THE BALL VALVE CLOSES THE FLOW PASSAGE THROUGH THE VALVE SEAT MEMBER AND THE BODY TO PREVENT FLOW OF FLUID THROUGH THE BODY, SAID FLUID PRESSURE OF FLUIDS FLOWING THROUGH THE VALVE SEAT MEMBER ACTING ON SAID PRESSURE SURFACE AREA MOVING SAID VALVE SEAT MEMBER AND BALL VALVE MEMBER TO SAID SECOND OPEN POSITION WHEN THE PRESSURE OF THE FLUIDS FLOWING THROUGH THE BALL VALVE AND THE VALVE SEAT MEMBER AND THE BODY PASSAGE EXCEEDS A PREDETERMINED VALUE IN EXCESS OF THE FORCE EXERTED ON SAID VALVE SEAT MEMBER BY SAID BIASING MEANS, SAID VALVE SEAT BIASING MEANS AND SAID ACTUATING MEANS ACTING ON SAID VALVE SEAT MEMBER AND SAID BALL VALVE MEMBER TO MOVE THE VALVE SEAT MEMBER AND THE BALL VALVE MEMBER TO SAID FIRST CLOSED POSITION WHEN THE PRESSURE OF THE FLUIDS FLOWING THROUGH THE VALVE SEAT MEMBER AND BALL VALVE MEMBER DECLINES BELOW A PREDETERMINED VALUE.