Process Engineering Division – Instrumentation and Automation Section – Daily Question – Question from 2020-07-12
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Process Engineering Division – Instrumentation and Automation Section – Daily Question – Question from 2020-07-12: Discussion question: 176. How to verify the rated travel deviation of pneumatic control valves?
By introducing a 120% signal into the actuator chamber, the ratio of the additional travel of the valve stem from 100% to 120% signal to the rated travel is known as the rated travel deviation (this is intended to ensure that the air-operated valve closes properly).
At 5 o’clock, the control unit sends signals of 4, 8, 12, 16, and 20 mA respectively; the actual valve position on site is checked, and the deviation is calculated
The specified input signal is smoothly applied to the actuator (or positioner) in an increasing or decreasing direction, and the corresponding stroke value is measured; the errors at various points between the actual \"signal-stroke\" relationship and the theoretical relationship are determined
The specified input signal is smoothly applied to the actuator (or positioner) in an increasing or decreasing direction, and the corresponding stroke value is measured; the errors at various points between the actual \"signal-stroke\" relationship and the theoretical relationship are determined
By introducing a 120% signal into the actuator chamber, the ratio of the additional travel of the valve stem from 100% to 120% to the rated travel is known as the rated travel deviation (this is intended to ensure that the air-operated valve can close properly).
When a 120% signal is applied to the actuation chamber, the ratio of the additional travel of the valve stem from 0% to 120% to the rated travel is known as the rated travel deviation.
By introducing a 120% signal into the actuator chamber, the ratio of the additional travel of the valve stem from 100% to 120% signal to the rated travel is known as the rated travel deviation (this is intended to ensure that the air-operated control valve can close fully).
By introducing a 120% signal into the actuator chamber, the ratio of the additional travel of the valve stem from 100% to 120% signal to the rated travel is known as the rated travel deviation (this is intended to ensure that the air-operated control valve can close fully).
By introducing a 120% signal into the actuator chamber, the ratio of the additional travel of the valve stem from 100% to 120% signal to the rated travel is known as the rated travel deviation (this is intended to ensure that the air-operated control valve can close fully).
The specified input signal is smoothly applied to the actuator (or positioner) in an increasing or decreasing direction, and the corresponding stroke value is measured; the errors at various points between the actual \"signal-stroke\" relationship and the theoretical relationship are determined