What does the dead zone of a control valve mean in simple terms?
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What does the dead zone of a control valve mean in simple terms? What is the impact of the dead zone on the valve?
Dead zone is a common phenomenon that refers to the range or width of controller output (CO) values for which no change can be induced in the process variable (PV) being measured when the input signal changes direction. The dead zone is the main contributor to excessive process deviation. For various reasons such as friction, drift, valve stem torsion, and dead zones in amplifiers or spools, control valve assemblies can be a major source of dead zones in an instrumentation loop.
Does it refer to the meaning of “idle travel”?
Is that dead zone inevitable? Is the dead zone a factor to consider when choosing instruments?
The change in the input signal at which a noticeable movement of the valve stem occurs, as the input signal to the control valve increases or decreases, is called the dead zone.
“Is a “detectable movement” simply the absence of movement or response?
The dead zone of a valve refers to a certain range in which changes in the input signal controlling the valve occur without any change in the output. The main causes of this dead zone are friction between the internal components of the valve, among other factors~~
Dead zone is a common phenomenon that refers to the range or width of controller output (CO) values for which no change can be induced in the process variable (PV) being measured when the input signal changes direction. That’s a very professional way of putting it
Is there anyone skilled enough to see my reply? I also asked another question: Do control valves equipped with valve positioners have a dead zone?
Theoretically, it doesn’t exist; in practice, it definitely does. The locator eliminates some mechanical failures but introduces signal failures. . . For the specific meaning of dead zone, please search on Baidu by yourself~ However, a dead zone is not entirely undesirable; sometimes an artificial dead zone of ±0.5% is introduced in the configuration to prevent frequent operation of the valve, such as at the 50% control point in step control
This post was last edited by oiloper on 2016-3-16 17:27. Uh, thanks! Here, two different dead zones are referred to: one is between the controller’s output and the actuator’s movement, and this dead zone can theoretically be eliminated when a positioner is used. The other is the input and output of the controller, where a dead zone can be artificially created. Is that how it should be understood? So the poster is probably asking about the second scenario