API SPEC 16D:2018

This specification establishes design standards for systems used to control blowout preventers (BOPs) and associated valves that control well pressure during drilling operations. The design standards applicable to subsystems and components do not include material selection and manufacturing process details but may serve as an aid to the purchaser. Although diverters are not considered well control devices, their controls are often incorporated as part of the BOP control system and therefore are included in this specification. The requirements provided in this specification apply to the following control system categories:
control systems for surface mounted BOP stacks;
control systems for subsea BOP stacks (common elements);
discrete hydraulic control systems for subsea BOP stacks;
electro-hydraulic/multiplex control systems for subsea BOP stacks;
control systems for diverter equipment;
auxiliary equipment control systems and interfaces;
emergency disconnect sequenced systems;
backup systems;
special deepwater/harsh environment features.