US Patent 11873699 Single solenoid valve electro-hydraulic control system that actuates control valve

An electro-hydraulic control system for actuating a control valve includes a control module. The control module is coupled to the surface via two hydraulic lines and an electric line. The control module uses one of the hydraulic lines as an “open” line and the other line as a “close” line. The control module includes a normally closed (NC) solenoid valve (SOV) that is coupled to the electric line and can be controlled from the surface to open or close. The opening or closing of the NC SOV in cooperation with hydraulic pressure on an “open” or “close” line of the hydraulic lines operates (i.e., closes or opens) the control valve.