| 主权项 |
1. An apparatus for controlling a back pressure control system, wherein the 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, the apparatus comprising:
an air source; a pneumatic pump in fluid communication with a control fluid storage vessel, wherein the pneumatic pump is operated via air supplied from the air source; an air storage vessel in fluid communication with the air source, wherein the air storage vessel is fluidly isolated from the pneumatic pump; a control fluid pressure control system, wherein the control fluid pressure control system comprises:
one or more valves configured to regulate a flow of control fluid: i) from at least one of the pneumatic pump and a control fluid accumulator to the back pressure control system, and ii) from the 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, the control fluid accumulator configured to maintain a supply of pressurized control fluid;flow control devices in fluid communication with the air storage vessel, wherein the flow control devices operate the one or more valves; wherein, when the air source supply is interrupted, the control fluid pressure control system continues controlling the pressure of the control fluid via air stored in the air storage vessel and via control fluid accumulated in the control fluid accumulator. |
