Patent ID: 8893796

Claim:
A wellbore valve assembly including a valve member which is moveable relative to a valve seat, the valve assembly being receivable in a wellbore tubing having a first end and a second end, the valve member being moveable between an open position relative to the valve seat, and a position in which the valve member is seated against the valve seat, the valve assembly including a valve member biasing device for biasing the valve member in a first direction towards the open position, wherein the valve member is moveable against the biasing force, towards the seated position, in the event of a force which exceeds a first predetermined value being applied in generally the opposite direction to the biasing force applicable by the valve member biasing device, and wherein the valve member is moveable against the biasing force, towards the seated position, in the event of a force which exceeds a second predetermined value being applied in generally the same direction as the biasing force applicable by the valve member biasing device.