Answer / magi

Exact positioning of the valve stem
To minimise hysterisis
To linerise a nonlinear system
To use in place where actuator cant produce sufficien force
to move the valve stem

Answer / satish m. patel, bilimora

The valve positioner is used for following reasons.
1. quick action control valve.
2. valve hysteresis.
3. valve used on viscous liquids.
4. split range.
5. line pressure changes on valve.
6. valve bench set not standard.
7. reversing valve operation.

Answer / sathis.b

we control the valve thru the positioner for the require
percentage we need.

for ex: if u want to open the valve 25%, the command give
from control room it will open or close thru' the
positioner also the forward or reverese of the valve
direction.

Answer / vinesh prajapati ,guj. +919974

1) Reduces HYSTERESIS due to function at gland portion
2) Improves Linearity
3) Works as a volume booster and Thus improve the speed of
Actuator opretion
4) Works as a span amplifier when spring range of actuator
is not 0.2 to 1.0 Kg/Cm2
5) Required whenever spli range control is required

Answer / vigneshkumar

Positioner:
A Positioner is like a proportinal Controller.The Set point is the control signal from the primary controller and the controlled variable is the Valve position.

Uses:

1.When the signal Pressure is not enough to operate the control Valve.
2.To make Split range between the valves.
3. It can be used to reverse the action of the actuator from air to open and to air to close & Vice Versa
4.To minimize the effect of Hystersis Effect.
5.To Minimize the Response time for the valve.
6.If the Actuator is spring less Positioner will be used.
7.If the Valve has high friction .

Answer / ddd

CONTINUOS FEED BACK /HYSTERSIS/BOOST UP AIR FOR OUTPUT

How to O2 analyzer works?

1 Answers  

what is the input of ph sensor and meter during the calibration time and what is the output?

1 Answers   Sabic,

how can we measure the pressure in underground cooling water pipeline by using pressure transmitter?what about the tapping position?

2 Answers  

What are the two program execution modes of PLC?

4 Answers  

what is difference between HOT permit and cold permit

0 Answers   Petro Rabigh,

If a warning lamp will operate with the ground circuit is bypassed with a jumper wire to ground, what should you check?

0 Answers  

POSSITIVE PULSE IS APPLIED TO AN INVERTER INPUT.THE TIME FROM THE LEADING EDGE OF THE INPUT TO THE LEADING EDGE OF THE OUTPUT IS 10 ns. THE TIME FROM THE TRAILING EDGE OF THE INPUT TO THE TRYLING EDGE OF THE OUTPUT IS 8 ns. WHAT ARE THE VALUES OF tPLH and tPHL?

0 Answers  

Different between control valve and mov

2 Answers  

1)What is the suitable MOC for flow meters working at temperature between 200 - 250 cen. 2)In which application the mass flow meters are not advisable 3)Is it advisable to use radiation type or radar type instrument for non contact application

1 Answers  

Working principle capacitance type level transmitter

3 Answers  

HI FRIENDS IHAVE QUESTION 1.WHAT IS PARTIALSTROKE TEST?WHY IT IS USED ON ESD ON OFF VALVES?

3 Answers   KNPC, Rotork,

How to calibrate level switch?

2 Answers   Power Plant, Sabic,