can any one tell leakage class in control valve depend on which parameter and there is any specific table or chart for selection of valve leakage class

2 Answers  

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WHAT IS TMXT IN TEMPERATURE FOUNDATION FIELDBUS.

0 Answers  

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In control valve there are two type of valve seat we can use metal to metal seat & soft seat.On this valve seat i have following doubt. 1)I have never seen practically the internal assembly of valve so my doubt is that basically weather the seat is soft seat or metal its basic MOC is same as valve body(SS or CS) only in soft seat we are using PTFE ring & place on valve seat & in metal this PTFE ring is not threr am i correct??????? 2)what are the common general rule for using metal to metal seat & soft seat,means its depend on process parameter like liquid,gas, steam & on valve leakage class.

1 Answers  

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how can you set a zero and span of transmitter?

1 Answers   Rockwell,

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Hi buddies! my name is sachin and i am working as a electrical and instrumentation engineer in a paper plant. right now i am facing a problem and if someone could help me it will be an immense pleasure to me. i am using AC 800M to synchronise DCS500 drives on paper machine and rewinder.communication is on PROFIBUS and we are using NPBA-01 module to link profibus to DC drives.But these days two of these drives are showing a error named FIELDBUS COMM.TIMED OUT and the drives get tripped.I have changed the NPBA module and PROFIBUS cable.So if anyone can do please help me out with this problem.I'll be highly grateful.

0 Answers  

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the basic of a DP flow transmitter are the following

1 Answers  

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Why the industry's standard current standards are from 4mA to 20mA,not from 0mA or any other range?

3 Answers  

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why dead weight tester called dead weight tester.

5 Answers   QAFCO,

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1. What means HART communicator / where it is used / how to use it? 2. Types of Thermocouples and its temperature ranges / output of thermocouple? 3. Types of RTDs and its temperature ranges / output of RTD? 4. Idea about Temperature Transmitters? 5. Difference between Analog and Digital signals? 6. Difference between “2 wire” and “4 wire” system / instruments? 7. Difference between “Potential” and “Potential free” contact? 8. Types of flow meters / transmitters? 9. Types of level transmitters? 10. Difference between “Power/Control” cable and “Instrument” cable? 11. What means “shield” and “screen” in cables / how it is useful? 12. Draw a schematic of closed loop circuit of flow / level / pressure / temperature? 13. Idea about calibration of Control valve / positioned / I/P? 14. How to bypass a digital/analog signal in PLC/DCS by hardwire and software?

6 Answers   JSL,

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what is zenier barier and what means zone 1,zone 2,and zone 3

2 Answers   Bapco Bahrain Petroleum Company,

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What are the different modes of a contollogix family processor? How they work?

3 Answers   Honeywell, Siemens,

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What are the disadvantages of Human-Machine Interface (HMI)? atleast 3.

1 Answers  

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