What does it mean to choose high or low?
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This post was last edited by dongliangsir on 2012-7-1 12:02. What is meant by \"high selection\"? What does low selection mean? And control methods?
For high values, HS can be used; for low values, LS can be used. It can be understood as a selector switch that is activated when the level, flow rate, pressure, or temperature is high or low, and it represents another control method.
I don’t quite agree with what was said on the second floor. High/low selection is more commonly found in pressure control circuits; such selectors usually have two or more signal inputs. The selector compares these input signals and selects the higher (lower) one as the valid signal, which is then sent to the actuator below. In simple terms, a selector compares all the input signals and then outputs the one that meets the criteria (in the case of a high-level selection, it selects the high-level signal) as the valid signal. Generally, this setup is intended for safety reasons, as well as to optimize operations. The action of this control point can affect two or even more parameters, and the desired action for the control valve in relation to these parameters may be to increase or decrease its opening degree – it’s possible to need it to open more or less. This results in multiple action requirements or different degrees of action for a single control valve, leading to conflicts; sometimes such conflicts can have fatal consequences, so it is necessary to decide which of these requirements should be met first. Use high (low) selection to pick the safe (all are reasonable requirements) and more reasonable requirement for adjustment
Everyone, is there any more proper answer?
I said timidly that large-scale units are also used quite frequently; several control signals act on one or more control components at the same time. For safety reasons, these control signals are compared with each other, and it only accepts commands from the signal with the higher value. Once its value drops below that of another signal, that signal takes over.
For example, use high selection for double-acting slide valves, and low selection for high-temperature butterfly valves! Enhance understanding
For high selection and low selection, the two variables should be controlled by a controller using a useful signal to drive the actuator
Just completed training! Just as you said! Hehe!