Abstract: A method and apparatus for controlling a control valve. A primary line is pressurized to move according to an operating sequence to move a first piston within a first housing from a reset position to a close position such that a first control valve is switched to a closed state. The primary line is pressurized according to the operating sequence to move the first piston within the first housing from the close position to an open position such that the first control valve is switched to an open state. The secondary line is pressurized according to the operating sequence to move the first piston within the first housing back into the reset position.

Abstract: A method and apparatus for controlling a control valve. A primary line is pressurized according to an operating sequence to move a piston within a housing such that one of an open line port and a close line port is in fluid communication with a selected chamber of a first control chamber and a second control chamber of a plurality of chambers defined between the piston and the housing. A secondary line is pressurized to move hydraulic fluid through the selected chamber and through the one of the open line port and the close line port in fluid communication with the selected chamber to thereby control a state of a control valve. The primary line and the secondary line are pressurized simultaneously according to the operating sequence. The primary line is vented, while the secondary line remains pressurized, to reset a position of the piston within the housing.

Abstract: A method and apparatus for controlling a control valve. A primary line is pressurized to move according to an operating sequence to move a first piston within a first housing from a reset position to a close position such that a first control valve is switched to a closed state. The primary line is pressurized according to the operating sequence to move the first piston within the first housing from the close position to an open position such that the first control valve is switched to an open state. The secondary line is pressurized according to the operating sequence to move the first piston within the first housing back into the reset position.