Abstract: An isolation valve for use with a tubular string includes a tubular housing for connection with the tubular string. A closure member is disposed in the housing and movable between an open position and a closed position. A flow tube is longitudinally movable relative to the housing for opening the closure member. A piston is coupled to the flow tube for moving the flow tube, and a fluid chamber is formed between the flow tube and the housing and receiving the piston. The isolation valve having a first fluid passage for fluid communication between a first portion of the chamber and a control line for moving the piston in a first direction, and a second fluid passage for fluid communication between a second portion of the chamber and a bore of the tubular string for moving the piston in a second direction.

Abstract: An isolation valve for use with a tubular string includes a tubular housing for connection with the tubular string; a closure member disposed in the housing and movable between an open position and a closed position; a flow tube longitudinally movable relative to the housing for opening the closure member; a piston for moving the flow tube; a fluid chamber formed between the flow tube and the housing and receiving the piston; a first fluid passage for fluid communication between a first portion of the chamber and a control line and for moving the piston in a first direction; and a second fluid passage for fluid communication between a second portion of the chamber and a bore of the tubular string and for moving the piston in a second direction. A single control line may be used to operate the isolation valve between an open position and a closed position.