Answer / raj anu raj

the valve will go to its fail safe position ie.. either
open or close

Answer / varathan

when communication failure occurs, Valve positioner have
three different action depend on application.
1. Fail to close
2. Fail to open
3. Fail to Standstill.(remain in the previous position)
Note: In automatic closed loop system, during failure
condition; controller must be forced back to manual mode
for safe operation

Answer / vijay singh

if profibus fails in operation.Valve positioner have
different action depend on application.
1.if valve is fail to open then valve will be in fully open
position
2.if valve is fail to close then valve will be in fully
close position.

Answer / ecxlsync

in an event of profibus failure or an absence of command signal, some valves will remain its current position, some will return to its safe position (fail safe).
There are valves designed to fully close (Fail to Close) or Fully Open (Fail to Open) in an event of failure.

Answer / jignesh parekh

during fail of profibus a valve be remain as it is. because
there is no command to travel a control valve move close or
open.

why relays are used with plc?

4 Answers  

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What is limitation of the ht.of the displacer of a level trol?

0 Answers   CCIE,

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principle of rtd

4 Answers  

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how to make a calliberation for deffirential pressure

3 Answers  

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i need some objective type questions in instrumentation

0 Answers  

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Consider a level troll. i am getting a correct value in 4mA and 20mA. the value in the middle(30 to 60%)is disturbed and i am not getting the appropriate value. what is the solution to normalize the level and to get the correct value..

2 Answers   KNPC,

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please send the sample qustion paper for iocl written test ..

0 Answers   IOCL,

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In my plant I want to mount a steam flow transmitter .Flow nozzel is already mounted in steam line .So how can i know the range to put in flow transmitter?

1 Answers  

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what does it mean an active front end in vfd plz explain it briefly

0 Answers  

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can anyone guide me how to get any of the previous year GAIL question papers? are they available? 0n 2nd august i have to take the written test.

0 Answers  

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what do you know about Foundation Fieldbus?

1 Answers   CCIE,

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Identify and use the ANSI/ISA-S5.1 consensus industrial standard process symbols.

0 Answers   GAIL, Olympia,

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