| 摘要 |
A multi-functional or versatile emergency shutdown valve controller may be used in various different emergency shutdown configurations to enable the testing of different types and configurations of emergency shutdown devices and the supporting equipment associated therewith. In one example, a digital valve controller for use with an emergency shutdown valve includes two pressure sensors and is adapted to be connected to a pneumatic valve actuator and to a solenoid valve device to assist in the on-line testing of the valve actuator as well as in the on-line testing of the solenoid valve. To perform testing of the solenoid valve, the valve controller may measure the pressure at different ports of the solenoid valve as the solenoid valve is actuated for a very short period of time. The valve controller may determine whether the solenoid device is fully functional or operational based on the derivative of the difference between the measured pressure signals, i.e., based on the rate of change of the difference between the measured pressure signals over time.
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