Valve failure modes: What do FI and FR mean?
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I’ve seen FO and FC, but what does this mean? FI = Fail to Intact FR = Fail to Remain Please advise, thank you
Take a look at the functional indicators and graphic symbols for process measurement and control instruments in HG/T 20505-2014
There’s nothing consistent here; I checked and both of them mean to maintain
Is FI any position, and is FR reset?
They all mean fault retention; it is necessary to check the circuit diagram for specifics. There are differences between the signal circuit and the air supply circuit.
FI should be fault retention, and FR is also fault retention, right?
The English I looked up means the same thing, but it doesn’t seem right to me. What is FL?
FL should be fault lock, I guess. fail lock