@LittleInch & gerhardl>> Thanks for the feedback. However, i am still a little confused.
Let me extract one case example and post here and then take up the discussion for further understanding.
For a single-acting actuator pneumatic valve, how does fail hold work?
For a fail safe condition (FSC or FSO) the air is released to ensure that the valve moves to the fail safe condition. Similar action happens indirectly via SOV/ Positioner ports in case of electric failure.
As i...
Hi Muktiadi,
The question is not specific to a particular valve but to many such valves.
These valves remain in open position (100%) and function as EIV when the upstream supply is cut or some abnormality downstream of the valves (fail safe close).
In one such case this is a 8", 900# RF...
@muktiadi and @19081984 >>> Thanks for the feedback.
Would welcome more view points on the discussion from other members.
Also, i need an answer to the question as in my original post; that if i have a Class-V valve (defined as control valve in datasheet) but only performing the funtion of a...
I am working at a petrochemical complex. We have a lot of control valves that need to be tested during Shutdown for leak tests.
I am a little confused as to which standard should be used for valve seat leakage tests and hydrotests (shell test). As i understand, FCI-70-2 is specifically...
