Interested to Buy Any Domain ? << Click Here >> for more details...
In dcs contol valve parameters showing like this
Gain=1 or 2 , ti=7 sec, td=20sec. But temp,pressure,level control valves we are using in which type parameter side using ti,td clearly tell me
- 1 Answers
- 4526 Views
- I also Faced
- E-Mail Answers
Answer Posted / carl_ellis
Gain, ti and td are PID proportional control tuning terms/constants. PID controllers use PID tuning constants to calculate an output based on the error signal; final control elements (valves) do not do a PID calculation so valves are not involved with gain, ti and td. The controller is typically in the control room, the valve is somewhere out in the process.
A PID controller calculates the expected valve/damper position from the error signal and the tuning constants, the result of which is an output control signal ranging from 0-100%.
A valve positioner or valve I/P receives that control signal from a controller (4-20mA, Profibus) and supplies air or electric power to the actuator to achieve the correct position demanded by the control signal.
Ti is the term for reset or integration. It is used when the process itself is not an integrating process. Level, pressure, and pH are usually integrating processes. Sometimes temperature is an integrating process, sometimes not. When the process is non-self regulating/integrating process, the ti term is not used in the PID calculation.
Flow and temperature processes typically use the ti term for PID calculation.
An exception to the rule of PID being done in a separate controller is Foundation Fieldbus (FF), which allows function block PID execution in FF devices. In a case where PID control is executed in an FF valve positioner, then a valve would use the PID tuning constants.
| Is This Answer Correct ? | 4 Yes | 0 No |
Post New Answer View All Answers
What is first echo & echo window in radar type level transmitter?
Q- Control problem are mainly classified in _____ types. a-)4 b-)3 c-)6 d-)nono of these Few of them i know is 1- regulator type problem (eg- Air conditioner) 2- tracking problem (eg missile trcking problem) 3- sybernatics 4- optimal control problem
Draw a group of instruments interlocked to a Pump & Motor?
Why do we floating DC in DC system.
How RAL(Rotary air lock)works in cement industry?
what is RTV function in in process control?
What are different types of valves?
In most instances, Inertia processes are quite uncommon. Give an example of a combined Resistance and Capacitance situation.Describe an application, which according to your understanding of the subject matter, comprises of both Resistance and Capacitance effects.
How to Calibrate Vortex Flow transmitter in field
what is interface level measurement.who can calibrate interface level measurement transmitter online
Senior engineer's please help me, what is Loop Checking and Loop test? and write difference also? soon urgent
sir ,iam in dem urgent need of HPCL Paper of Instrumentation Branch plz send me at your earliest convenience at ujjwal_sharma1983@yahoo.com
Derive capacitance to 4-20ma conversion formula / relation in capacitance type pressure sensor?
There are many type of control cable like pair,core,tried, What are defination each one
typical loop drawing of a simple feedback control comprising of one transmitter and one control
