Patent ID: 7621293

Claim:
A fluid process control system comprising: a control valve movable between a first position and a shutdown position; a valve controller for controlling actuation of the control valve between the first position and the shutdown position; a fluid control line coupled to the valve controller to cause movement of the control valve; supporting equipment coupled on the fluid control line operable to actuate the control valve from the first position toward the shutdown position; a first pressure sensor communicatively coupled to the valve controller and operable to detect a first pressure at a first location on the fluid control line during operation of the supporting equipment, the first pressure being an inlet pressure of the supporting equipment; a second pressure sensor communicatively coupled to the valve controller and operable to detect a second pressure at a second location on the fluid control line that is distinct from the first location during operation of the supporting equipment, the second pressure being an outlet pressure of the supporting equipment; an emergency shutdown controller communicatively connected to the supporting equipment for actuating the supporting equipment during an emergency shutdown test; logic implemented by the valve controller to determine an operational condition of the supporting equipment during the emergency shutdown test based on at least one of the first pressure and the second pressure; a processor in the valve controller that implements the logic to determine a pressure differential between the inlet pressure and the outlet pressure and a rate of change of the pressure differential during operation of the supporting equipment; and a memory in the valve controller that stores a threshold rate and the processor compares the rate of change to the threshold rate to determine the operational condition of the supporting equipment.