Well Control Equipment
Well control equipment includes all equipment used to:

detect unplanned influxes of formation fluids into the well;
prevent, control or divert the flow of fluids from the well;
purge formation fluids from the well;
separate formation fluids from the drilling fluid.
It includes monitoring and indication equipment for pit levels, flow detection, low and pressure measurement and other important instrumentation required for recognizing and responding to an unplanned change in well parameters which could result in a loss of well control.
It includes surface, downhole and internal blowout preventers, rotating heads, circulating heads, tubing injection heads, diverters, wireline lubricators and stuffing boxes, kelly cocks, stabbing valves, choke lines and manifolds, mud gas separators, kill-lines, valves and other equipment required for killing a well including high-pressure kill pumps and plugs, valves and other devices necessary to prevent a well from flowing. It also includes all pipework associated with the above equipment.