Answer / naseer jarral

i/p recive the signel 4 to 20 ma and calibration time when
we give 4 ma it gives penumatic out put valves position
that time is moniterd by by positioner it is 0% or 100% and
when we give 12ma valves stem position that time 50% on
12ma positioner will recive the current sigenel and campare
it with valve stem if the valve stem position is not same
it will produse penumatic out put on same 12 ma more till
it will not match with the position of valve stem when the
on 12ma valve position is 50% then this will close the
penumatic out put and close the nozel with fleper and block
the air till current signel changes(.... it compare the
current signal with valve position through valve stem it
genrate penumatic out put till differenc between current
signel and valve position.....)

Answer / bhupesh pal

Valve Positioner Behaves like a control loop,It measure the
previous position of the stem of the control valve and
according to the new i/p (4-20 mA)adjust the new position
of the Stem of the contol valve.

Answer / hiren popat

All valve can not be actuate directly using I to P
converter. Using electropneumatic valve positioner we can
boost the air singal to the required level to actuate valve
and position it such that the flow of material passing
through line is maintain

Answer / venkat

to reduce and to control the flow of the service which is
passing through

On drum level, why we are using air to close Control valve?

4 Answers   L&T,

---

when the operation engineer told you that he gives the control valve order to open but there is no response ! what will you do ? and if you found that there is astuck , what will you do ? (note : it is apanumatic valve )

5 Answers  

---

What is MLFB number for Siemens?N How they are defined?Give me Answer with example like take any Signal module....

1 Answers  

---

please tell me what is a light up procedure of Cfbc boiler and what it's axuillaries of cfbc boiler?

0 Answers   Wartsila,

---

What is the meaning of wet leg

0 Answers  

---

What does PCU means with respect to Dead Weight Tester?

1 Answers   SGS,

---

WHAT IS THE DIFFERENCE B/W PLC and DCS

10 Answers   Bhel,

---

Why 4-20 amps is being used in instruments? Why cant we use any other range instead of 4-20 amps? Why only 4 amps is taken as lower limit and why 20 amps is taken as the higher limit?

0 Answers  

---

Why Differential pressure transmitter is located below the tappings points for steam & condensible vapor flow measurement application?

2 Answers  

---

how to check thermocouple ,its working or not?

14 Answers   Coca Cola, Ford, Honeywell,

---

difference between repeatability and reproductability

1 Answers   IOCL,

---

hello this is dhinakar subramanian. how to piping and instrumenation drawings and also how to create the data sheets...

1 Answers  

---