what is the meaning of reverse action and forward action of
control valve...
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Answer Posted / vinayak
Hi ...
Revese action normally used in AIR Fail to Close valve.
Direct acttion normally used for Fail Open valve.
It is very important to define reverse or direct action as
per process requirement.
DIRECT ACTION :
20 MA DC = 0 % VALVE CLOSE
16 MA DC = 25 % VALVE OPEN
12 MA DC = 50 % VALVE OPEN
8 MA DC = 75 % VALVE OPEN
4 MA DC = 100 % VALVE OPEN
REVERSE ACTION :
4 MA DC = 0 % VALVE CLOSE
8 MA DC = 25 % VALVE OPEN
12 MA DC = 50 % VALVE OPEN
16 MA DC = 75 % VALVE OPEN
20 MA DC = 100 % VALVE OPEN
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