Could someone take a look at this cut-off valve XV1001A and tell me what the control mechanism for it is?
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I’d like to sort out the controls here, thank you
For example, what does ZSO ZI NDE SS S mean? Thank you
There are two issues with this diagram: 1) There are problems with the two zso values; it should be one zso and one zsc； 2) Can accident-safe interlocking be achieved with nde? Should we use ne?
I also have a flowchart; I’m currently learning about it. My team leader only mentioned interlocking, but I don’t know the specifics yet because I haven’t started learning formally
Z refers to position detection ； S is the switch ； O stands for OPEN, meaning an open position. So ZSO is used for open-position detection ； ZI refers to valve position transmission, a 4~20mA signal ； Two ZSOs are not out of the question, if the valve’s open position is an important detection signal. But the tag numbers cannot repeat. S on the solenoid valve and the coil ； SS is an interlocking signal. NDE stands for normal de-energized, meaning it is in a normal non-excitation state; it becomes energized when interlocked. The two solenoids are connected in parallel, which improves reliability – if one fails, the other can continue to function properly.
Sorry, I didn’t look at the picture carefully. Personally, I think there’s a problem with the legend. It is neither in parallel nor in series. Reference can be made to clause 7.4.5 of the explanatory notes in \"GB/T 50770-2013 Code for Design of Safety Instrumented Systems in Petrochemical Industries\"; there is a legend provided.
The two ZSOs are likely intended to enhance reliability for safety reasons
Thank you, you explained it in great detail; many thanks
Does it look like valve control for a vaporization furnace?