X
Hello,
i am working with instrumentation engg group. we are come across control valve datasheets in which the fail action is fail locked drift close and fail locked drift open. What we know are Fail open, Fail close and Fail Last. now in all datasheet they have use lock up relay (Fisher 164A), which will locked the actuator in last position in the case of air supply interrupted, so in this condition fail. position called Fail Last. now question is what kind of fail action is this (fail locked drift close or Fail locked drift open) and how does it work in real time? What kind of process application is this? Your efforts will be highly appreciated
Thank you
i am working with instrumentation engg group. we are come across control valve datasheets in which the fail action is fail locked drift close and fail locked drift open. What we know are Fail open, Fail close and Fail Last. now in all datasheet they have use lock up relay (Fisher 164A), which will locked the actuator in last position in the case of air supply interrupted, so in this condition fail. position called Fail Last. now question is what kind of fail action is this (fail locked drift close or Fail locked drift open) and how does it work in real time? What kind of process application is this? Your efforts will be highly appreciated
Thank you