VALVE AND METHOD OF OPERATING A VALVE

摘要

An oil or gas well valve, having a movable ball and a cutting device arranged to shear against an anvil member when the ball is moving between open and closed configurations; and having a sealing member providing a seat when the valve is closed. The sealing member is configured to move away from the ball when the ball is moving between the open and closed configurations, so that during opening and closing the sealing member is displaced away from the cutting device.