Automatic and manual adjustment methods for control valves.
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Does anyone have a more detailed version of this?
Could you explain it in more detail?
Do you want an electric or a pneumatic one?
The term \"control valve\" is rather vague; manual valves can also be adjusted by changing their opening degree, while pneumatic and electric valves generally differ in terms of the actuators used.
Manual operation is generally used during startup/shutdown, load adjustment, or when dealing with abnormal situations; automatic mode can be adopted once production is stable. However, due to factors such as operating conditions and PID tuning of the instruments, some instruments do not function stably in automatic mode
Reply to 1# borling: Our station uses manually operated control valves, but we use the two control valves together, and the operation is fairly stable
Typical setup for control valve assemblies: Cut-off valves are installed before and after the control valve, along with an auxiliary line valve. Under normal conditions, the auxiliary line valve is closed while the cut-off valves are open, allowing automatic adjustment via the control valve. When the control valve develops problems and needs maintenance, the cut-off valves before and after it are closed and the auxiliary line valve is opened, enabling manual adjustment. Therefore, gate valves are generally used for cut-off valves, while globe valves are used for bypass valves.