what is the basic working principle of I/P and Positioner in any control valve.

12 Answers   Essar, Visa Steel,

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What is the difference between HMI and SCADA and MMI

4 Answers  

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Wht should be the ratio of natural frequency (Fn) to wake frequency (Fw) and wht if goes above the rato limit?

2 Answers  

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What is difference between “Fault Tolerant” & “Fault avoidance” PLC? Application where these system s are used?

0 Answers  

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i want to calibrate a transmitter in the range of -100 to 300 mmwc. How it is possible to measure -100 to 300?.

2 Answers   Hindalco,

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What is mean by Adapter block and net block?

1 Answers   Hospira,

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What is the difference b/w EMF, voltage & potential difference?

1 Answers  

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how to check control valve was passing?how to check online?

3 Answers  

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What are the maximum packet size of: a) HART b) Profibus DP c)Profibus PA d) DeviceNet e) Foundation Fieldbus

0 Answers   EIT,

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Q1: Consider part of a control loop, which excludes the transmitter, consisting of a process, a controller and a control valve which may be represented by two dead times of 0.5 min each and three exponential lags of 0.8 min., 1.0 min. and 1.5 min. respectively. We wish to express this system as an overall first order plus dead time (FOPLD) model ie gain, time constant and process dead time. (We will see later that this is often done, to simplify controller tuning). For this exercise, gain is considered to be 1.0. (A) If the transmitter is a flow transmitter whose behaviour can be described by a dead time of 0.2 min. and an exponential lag of 0.5 min. in terms of the overall dead time and overall first order lag how can the system behaviour be approximated ? Overall dead time = Overall time constant = (B) If the transmitter is a temperature transmitter with a temperature sensor in a protecting well whose behaviour can be described by a dead time of 0.7 min. and an exponential lag of 15 min. how can the overall system behaviour be approximated now? Overall dead time = Overall time constant =

0 Answers  

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What is mean by Ethernet, Device net and Control net? For what application we are using these?

4 Answers  

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There are many type of control cable like pair,core,tried, What are defination each one

0 Answers   Birla,

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