in a electronic controller why we are using 250 ohm resistance in input signal?is i/p is necessary in control valve when we are using electronic controller give details?

3 Answers   IOCL,

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why we use 24 vdc in instruments mostly?

2 Answers  

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What is Modbus communication

0 Answers  

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in yokogawa prosef rd safety PLC how to data send frome local SCS to other SCS and other FCS

2 Answers  

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What is the working principle of Dozing valve used in cement industry?

1 Answers  

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my temperature transmitter in field showing 700 degree , whereas in dcs showing 459 degree, how to resolve this?

4 Answers   ONGC,

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A DP transmitter is used to measure the level of an open tank. The drain line of the tank is connected to a control valve, and is configured as, if the level of the tank is 90% the valve should get open 10%. And if the tank level is 10%, the valve should get open 90%. Draw wiring diagram and explain how to configure DP transmitter and control valve using HART communicator. If the span error at output is 1%, what will be the %opening of the control valve at 60% level of the tank?

0 Answers  

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how the transmitter send MA?

1 Answers  

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What does PCU means with respect to Dead Weight Tester?

1 Answers   SGS,

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what is compensation in engineering and what is temperature compensation?

1 Answers   Binani, Yokogawa,

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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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what is the minimum power (P=VI)to produce a spark?

0 Answers  

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