Name four general (not technical) criteria that would you
consider important, when deciding upon a particular control
valve?
Answer Posted / rajesh
the fluid medium to be used
the fluid physical properties ( viscosity , density ,
temperature etc )
the frequency of application of valve i.e the no of times
opened or closed in a hour
the flow rate , pressure desired c time , volume to be
transferred in specific time for flowing media etc
the operation to control valve
manual , automatic , pneumatic , hydraulic etc
Is This Answer Correct ? | 2 Yes | 0 No |
Post New Answer View All Answers
how to rectify the poor signal strength in utrasonic digtial flow meter ,model:ge digital xce868i
How to fix back the valve actuator stem
Differentiate between ultrasonic flowmeter and radar type flow meter
Why do we floating DC in DC system.
Which type of diagphram use in costic line,DM water line,natural gas line,oil line?
How do bending tubing provide better measurement than using tubing fittings such as elbows?
sir ,iam in dem urgent need of HPCL Paper of Instrumentation Branch plz send me at your earliest convenience at ujjwal_sharma1983@yahoo.com
What is exact difference between the panel earthing and system earthing in DCS system. What is the value of resistence.
what is maxdna ?. explain about the software details.
What is the use of control cable?
what is isloted barrier how it works and what are the main purpose.how it make safe area.
what is function of switch, and how is it work, explain with difination
What is zener diode? What is voltage regulator?
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 =
i have used level transmitter in starch cooking preparation tank. tank total height 2mtr.sometime LT display shows some error value when tank is fully empty and diaphragm side i already checked okay no problem in diaphragm area. field cable checked 24volt and mA shows correct value while tank empty mA is 4mA. 4mA i needed that 0% but display showing 10% or 15% percentage values are varying continously please give any good solution for me.....