Operation of control valves

This post was last edited by CHANGBAISHI on 2018-7-3 08:26; parameters are set manually to verify the accuracy and flexibility of valve operation on-site. There is a dedicated signal generator for use in conjunction with it. When the instrument technician carries out the tuning, the involvement of process engineers is required; you’ll see why.

So how is it inspected before being put into use? What needs to be checked?

1. This assumes it is the preparatory work before actually starting to drive; the specific tasks to be carried out depend on your field of specialization: if you are a process operator, your main responsibilities involve participating in the inspections related to instrumentation, ensuring the quality of the work, and becoming familiar with the performance of the valves so as to have a clear understanding when operating them. Additionally, setting the output value (opening degree) for the valve is generally done by the process operators. If it is a gauge operator, the workload is slightly greater; first, it is necessary to check whether there are any defects in the overall appearance of the valve (valves that have been adjusted also need to be inspected), such as whether there are leaks in the gas supply lines, whether the electrical protection circuits are secure, and whether the gas pressure is within the proper range ； Secondly, the process needs to be run once; the operator sets the valve opening degree from the control system’s operation station (usually several points such as 20%, 40%, 60%, and 80% are selected within the range of 0–100%, and settings are made both for increasing and decreasing the opening). It is necessary to check whether the valves at the site operate correctly and whether the signals sent back to the control room are accurate. If not, the positioner can be adjusted until the desired performance is achieved. 2. If it is preparatory work during installation, tasks must be carried out step by step in accordance with construction standards, including inspection, aeration, power supply, debugging, and recording.

Learn* some on-site instrument tuning. After working in automatic control for so long, I’ve forgotten everything about the field work.

1. For single-unit calibration, use a laser level for on-site adjustment. 2. For joint calibration, use walkie-talkies to verify the correspondence between the control signal and the actual valve position on site.

Instrument engineers at various companies have thorough knowledge of operating such valves.

0%, 25%, 50%, 75%, 100%, 50%, 0% – comparisons between indoor and outdoor conditions at these valve settings are necessary as part of the manufacturing process.

It mainly involves checking the feedback signals, whether the positioner is positioning accurately, as well as the condition of the pressure relief valve, among other things.

How should one reply to such a brief message?