An apparatus for controlling at least one back pressure control system, wherein each back pressure control system includes a housing having an inlet, an outlet, and a pressure chamber; a shuttle assembly adapted to reciprocate in the pressure chamber to regulate the flow of an operating fluid from the inlet to the outlet; the operating fluid applying an opening force to a first end of the shuttle assembly; and a control fluid to apply a closing force to an opposite end of the shuttle assembly, whereby the apparatus further comprises: an air source for supplying air to the at least one back pressure control system; an air storage vessel in fluid communication with the air source; a control fluid storage vessel; a pneumatic pump in fluid communication with the control fluid storage vessel, wherein the pneumatic pump is operated via air supplied from the air source; at least one control fluid pressure control system for controlling a pressure of the control fluid, wherein each control fluid pressure control system comprises: one or more valves (114, 116, 118, 120) for regulating a flow of control fluid i) from at least one of the pneumatic pump, and a control fluid accumulator to the at least one back pressure control system, and ii) from the at least one back pressure control system to the control fluid storage vessel; the control fluid accumulator in fluid communication with the pneumatic pump and the one or more valves (114, 116, 118, 120) for regulating a flow of the control fluid; devices for operating the one or more valves (114, 116, 118, 120) via fluid communication with the air storage vessel; wherein, when the air source supply is interrupted, the at least one control fluid pressure control system can continue controlling the pressure of the control fluid via one or more of: air stored in the air storage vessel fed to the devices for operating the one or more valves (114, 116, 118, 120); and control fluid accumulated in the control fluid accumulator. an air source for supplying air to the at least one back pressure control system; an air storage vessel in fluid communication with the air source; a control fluid storage vessel; a pneumatic pump in fluid communication with the control fluid storage vessel, wherein the pneumatic pump is operated via air supplied from the air source; at least one control fluid pressure control system for controlling a pressure of the control fluid, wherein each control fluid pressure control system comprises: one or more valves (114, 116, 118, 120) for regulating a flow of control fluid i) from at least one of the pneumatic pump, and a control fluid accumulator to the at least one back pressure control system, and ii) from the at least one back pressure control system to the control fluid storage vessel; the control fluid accumulator in fluid communication with the pneumatic pump and the one or more valves (114, 116, 118, 120) for regulating a flow of the control fluid; devices for operating the one or more valves (114, 116, 118, 120) via fluid communication with the air storage vessel; one or more valves (114, 116, 118, 120) for regulating a flow of control fluid i) from at least one of the pneumatic pump, and a control fluid accumulator to the at least one back pressure control system, and ii) from the at least one back pressure control system to the control fluid storage vessel; the control fluid accumulator in fluid communication with the pneumatic pump and the one or more valves (114, 116, 118, 120) for regulating a flow of the control fluid; devices for operating the one or more valves (114, 116, 118, 120) via fluid communication with the air storage vessel; wherein, when the air source supply is interrupted, the at least one control fluid pressure control system can continue controlling the pressure of the control fluid via one or more of: air stored in the air storage vessel fed to the devices for operating the one or more valves (114, 116, 118, 120); and control fluid accumulated in the control fluid accumulator. air stored in the air storage vessel fed to the devices for operating the one or more valves (114, 116, 118, 120); and control fluid accumulated in the control fluid accumulator.