Need advice on PID drawings
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In the diagram, what does the “VK” in VK1801 below the valve mean? Those who are not quite sure have marked it in red. I would appreciate it if experts could give some guidance, or recommend any books that might be useful for understanding and creating diagrams. Thank you all in advance
Go to the first page of the schematic diagram for that project; there are explanations there. VK should be the prefix for the valve code of this project.
If there are any coding issues related to PID that you don’t understand, consult the legend right away. According to standard design conventions, PCV refers to a self-acting control valve; as indicated in the diagram, pressure is taken before the valve. There is a field pressure gauge connected after VK, and it is likely that this represents a shut-off valve for maintenance purposes at the base of the pressure gauge. Such valves can also be found in other locations; it’s likely that VK denotes a regular gate valve. FI should be a flow meter, while ACV is a programmable control valve. To determine exactly what type of valve it is, one needs to refer to the legend. In general, those with a semi-circular head are usually control valves, while those with a square head are also control valves. ZIO and ZIC respectively represent signals indicating the valve’s open position and closed position
1) If the PID is drawn in accordance with the legend requirements specified in HGT 20519-2009 \"Unified Regulations on the Content and Depth of Construction Drawings for Chemical Process Design\", then VK-XXXXX denotes the serial number of the ball valve. However, this is not a conventional practice in the industry; its purpose here is merely to assign numbers to different types of valves so that nameplates can be attached to them, facilitating operation. As long as the codes for ball valves, gate valves, check valves, and globe valves are unified, that will suffice ； PCV stands for self-acting control valve ； ACV stands for control valve, and the type of valve is a globe valve (this is not industry practice; it is merely a conclusion drawn based on consistency in your drawings) ； 2) Regarding the meaning of the letters and symbols used on instruments, it is recommended to first consult the relevant requirements specified in HGT 20505-2014 \"Functional Indicators and Graphic Symbols for Process Measurement and Control Instruments\"; there are too many codes involved.
The comments above cover everything; you can take a look at this attachment for the materials