Dead time reducer for piston actuator

A method of controlling a surge in a compressor, the method comprising the steps of:

• providing an antisurge valve in fluid communication with a compressor inlet and a compressor outlet, the antisurge valve being selectively transitional between a closed position and an open position, the antisurge valve being transitioned from the closed position to the open position to enable fluid flow from the compressor outlet to the compressor inlet through the antisurge valve;
• monitoring operation of the compressor and identifying an anticipated surge condition when compressor operational conditions exceed a prescribed threshold associated with compressor surge;
• exerting a closing force on the antisurge valve so as to maintain the antisurge valve in the closed position during normal operation of the compressor;
• and
• reducing the closing force by an amount in response to identification of the anticipated surge condition, the reduced closing force being sufficient to prevent the antisurge valve from transitioning to the open position.

A compressor antisurge control system comprising:

• a compressor having a compressor inlet and a compressor outlet, the compressor experiencing compressor surge in response to defined operational conditions;
• a surge controller operatively connected to the compressor and configured to monitor operation of the compressor and generate an antisurge signal when compressor operational conditions exceed a prescribed threshold associated with compressor surge;
• an antisurge valve in operative communication with the surge controller and fluidly connected to the compressor inlet and compressor outlet, the antisurge valve being selectively transitional between a closed position and an open position, the antisurge valve being transitioned from the closed position to the open position to enable fluid flow from the compressor outlet to the compressor inlet through the antisurge valve;
• and
• a valve actuator operatively coupled to the surge controller and the antisurge valve, the valve actuator being configured to exert a first closing force on the antisurge valve for closing the antisurge valve, the valve actuator being configured to exert a second closing force equal to only a portion of the first closing force on the antisurge valve in response to receiving the antisurge signal from the surge controller.