Patent ID: 8653985

Claim:
A production shutdown system for an underwater hydrocarbon production facility, comprising, on the topside: a safety system, a communications module, and an interface unit operably coupled with the safety system and in communication with the communications module; underwater: drive control means comprising a reversible solenoid drive and associated directional control valve controller card, and an underwater communications component; a safety communication channel extending between the topside interface unit and the underwater directional control valve controller card via the topside communications module and the underwater communications component, configured to pass safety signals received from the safety system to the directional control valve controller card, and wherein the safety system, the interface unit, and the reversible solenoid drive and associated directional control valve controller card are rated according to a prescribed safety integrity level (SIL) but the communications module and underwater communications component are not so rated, to thereby provide to SIL rated production shutdown system having both SIL rated components and a substantial number of non-SIL rated communication components.