API Spec 16D-2004 pdf download.Specification for Control Systems for Drilling Well Control Equipment and Control Systems for Diverter Equipment.
3.7 arm: To enable the operation of a critical function or functions. 3.8 backup: An element or system that is intended to be used only in the event that the primary element or system is non-func- tional. 3.9 blind ram BOP: A BOP having rams which seal against each other to close the wellbore in the absence of any pipe. 3.10 block position: The center position of a three-position control valve. 3.11 blowout: An uncontrolled flow of pressurized wellbore fluids. 3.12 BOP (blowout preventer): A device that allows the well to be sealed to confine the well fluids in the wellbore. 3.13 BOP closing ratio (ram BOP): A dimensionless factor equal to the area of the piston operator divided by area of the ram shaft. 3.14 BOP control system: The system of pumps, valves, accumulators, fluid storage and mixing equipment, manifold, pip- ing, hoses, control panels and other items necessary to hydraulically operate the BOP equipment. 3.15 BOP stack: The assembly of well control equipment including BOPs, spools, valves, and nipples connected to the top of the casing head. 3.16 BOP stack maximum rated wellbore pressure: The pressure containment rating of the ram BOPs in a stack. Note: In the event that the rams are rated at different pressures, the BOP stack maximum rated wellbore pressure is considered equal to the low- est rated ram BOP pressure. In stacks that do not contain any ram BOP, the BOP stack maximum rated wellbore pressure is considered equal to the lowest rated BOP pressure. 3.17 central control unit (CCU): The central control point for control and monitoring system functions and communica- tions. 3.18 check valve: A valve that allows flow through it in one direction only. 3.19 choke line: A high-pressure line connected below a BOP to transmit well fluid flow to the choke manifold during well control operations. 3.20 choke and kill valves: BOP stack-mounted valves that are connected below selected BOPs to allow access to the well- bore to either choke or kill the well.
3.22 commodity item: A manufactured product purchased by the control system manufacturer for use in the construction of control systems for drilling well control equipment. 3.23 control fluid: Hydraulic oil, water based fluid, or gas which, under pressure, pilots the operation of control valves or directly operates functions. 3.24 control hose bundle: A group of pilot and/or supply and/or control hoses assembled into a bundle covered with an outer protective sheath. 3.25 control line: A flexible hose or rigid line that transmits control fluid. 3.26 control manifold: The assemblage of valves, regulators, gauges and piping used to regulate pressures and control the flow of hydraulic power fluid to operate system functions. 3.27 control panel: An enclosure displaying an array of switches, push buttons, lights and/or valves and various pressure gauges or meters to control or monitor functions. Control panel types include: diverter panel; rig floor panel; master panel; and mini or auxiliary remote panel. All of these panels are remote from the main hydraulic manifold and can be pneumatic, electric or hydraulic powered. 1. Diverter Panel—A panel that is dedicated to the diverter and flowline system functions. 2. Rig Floor Panel (Driller’s Panel)—The BOP control panel mounted near the driller’s position on the rig floor. 3. Master Panel (Hydraulic or Electric)—The panel mounted in close proximity to the primary power fluid supply. All control functions are operable from this panel including all required regulators, gauges, meters, audible alarms, and visible alarms.