Don’t understand the gauge symbols
Thread Content
I’m just starting to work with instrument flowcharts, and I’m not sure what some of the symbols mean; I hope you can help me out
This diagram should have been extracted from the PID; generally, PIDs come with legends, including those for process and instrumentation aspects. Looking at the legends should make things clearer. Regarding this diagram of yours, FT stands for flow transmission, while FIQS represents the cumulative amount of flow. The instrument located higher up is likely part of the SIS system; XV is presumed to be a pneumatic shut-off valve. To confirm this, it’s necessary to check your PID settings and the process specifications.
FT stands for flow transmission, FIQS represents the cumulative amount of flow, and XV is a two-position pneumatic shut-off valve
FIQS stands for indication (I), accumulation (Q), and interlock (S) of instantaneous flow rate. It’s not just the cumulative traffic volume.
Learn about the functional indicators and graphic symbols for process measurement and control instruments as specified in HG/T 20505-2014
FT stands for flow transmission, FIQS represents the cumulative amount of flow, and XV is a two-position pneumatic shut-off valve
1. FIQS—indicates that the system functions are: flow indication, accumulation, and control (on/off)； 2. System functions are implemented in DCS ； 3. This is a feed flow rate control system, commonly used in batch feeding processes with intermittent operation. Feeding begins gradually, and when the cumulative value set by the process is reached, the feed valve (XV) is closed to complete one batch of feeding ； 4. FT—flow meter; XV—pneumatic two-position feed control valve.
By learning from the legend*, one should of course understand some principles of instruments
Interlocked control between flow rate and control valve: a flow rate feedback signal is sent to the control valve to regulate its opening degree, thereby controlling the flow rate