Valve fail safe action vs shutdown signal

[helpyou]

Hi

Is fail safe action for a shutdown valve the same as shutdown signal.. for example, if we change power failure action of valve to fail in last positon.. does it mean when it receives signal from shutdown system, valve will not close , instead it stays at last position ? Or they can be configured to be different ..holds last position at power failure and closes at shutdown signal?

Your inputs please from experience ..thanks

 

[mk3223]

To me, these are two different concepts.
The "shutdown" means to close down the stream and stop the flow. But, the "fail in last position" means to control the valve to stay at the current position while the system failed.