Can’t understand the gauge symbols
Thread Content
Question 1: The valve symbols for SSV ZS ZA ZT ZI are different. Could you explain this? What do UT UI U mean? It would be best to explain everything in detail. Thank you. Question 2: What does ESD emergency shutdown SD mean? What does “on the way” mean? Thank you
There should be a legend on the first page of the drawing, right?~~
I didn’t understand that. There are no special symbols anywhere. Write down what part of this PID you didn’t understand
1) SSV denotes the code for a safety shut-off valve; different design institutes use various notations for such valves, with some using SV； ZS ZA ZT ZI denotes valve position transmission and display (as well as display of the valve opening status) ； UT UI U is used for multi-variable transmission and display; U stands for multi-variable. Since this valve, PV-1024C, is equipped with a flow meter along with pressure compensation, such compensation is usually applied in order to accurately reflect the gas flow rate ； 2) SD stands for shutdown, which means to turn off ； It indicates that the ESD system’s detection signal triggers the valve to shut down.
I have a slight question: in the two diagrams, what is the purpose of the electrical connections of the two valves, PVC-1203C and SSV-1202C, to the pipes? Can pipes generate electrical signals? ? For the second valve, the pneumatic signal is obtained directly from the pipeline; the process medium at 6.3 MPa is used as instrument air to act on the valve’s actuator? Don’t you have any solenoid valves either? ? ?
Unless the legend states otherwise, there is a problem with the first diagram; as mentioned above, it makes no sense for electrical signals to be connected to process pipelines. There’s something upstairs that’s different from what the drawings show. In the first diagram, the signal for PCV1204C comes from the output of a low-select module, rather than being directly from the output of the PID module.
The diagram inside the double-dashed lines was provided by the equipment manufacturer, and it is incorrect. Thank you. Can I add you on QQ?
The less-than sign right next to FIC-1204C and PIC-1204C. The output of the minimum selection module is the smallest among several input variables. There is also a high-selection module, whose output is the majority among several variables.
At the beginning of PID, there are some graphics with explanations regarding its activation and deactivation. As for ESD... it is called the emergency shutdown system