Definition(s)
Blowout Preventer Operating and Control System (Closing Unit)
The assembly of pumps, valves, lines, accumulators, and other items necessary to open and close the blowout preventer equipment.
Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards
Blowout Preventer Control System (Closing Unit)
The assembly of pumps, valves, lines, accumulators, and other items necessary to open and close the blowout preventer equipment.
Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global Standards