Electro-Hydraulic (EH) Control System
A system utilizing electrical conductor wires in an armored subsea umbilical cable to transmit command signals to solenoid-operated valves which in turn activate pilot operated control valves assigned to functions. Note: One pair of wires is dedicated to each function.
Source: API SPEC 16D, Specification for Control Systems for Drilling Well Control Equipment and Control Systems for Diverter Equipment, Upstream Segment, Second Edition, July 2004. Global Standards