Answer Posted / ramesh dham

There are two works of positionar First is to boost up the pneumatic signal to desired spring range of actuator and second is to get mechanical feedback of valve stem to accurate control over valve.
if we do not use positionar then our valves spring range must lie between 3-15 psig also we can't control accurately the process with higher variation.

what is the difference between scaler and vector drive

2187

---

IS there any effect of vortex in low pressure side of the transmiter after the orific in feed water line? if yes then what is the calculation?

2400

---

tell me the field & lab calibration procedure step by step with diagram of pressure gauge, pressure switch, pressure transmitter, temperature switch, level switch, flow switch, flow transmitter, temperature transmitter, temperature indicator, flow indicator, level indicator, control valve, thermocouple, pressure indicator (digital & analogue),

2315

---

Please can anybody help for control valve sizing step by step procedure?

2131

---

Why 4-20 amps is being used in instruments? Why cant we use any other range instead of 4-20 amps? Why only 4 amps is taken as lower limit and why 20 amps is taken as the higher limit?

1528

---

send me HPCL paper

10315

---

What is zero elevation and zero suppression?

2174

---

what is performance test.need defination

1718

---

Calibration procedure for water rotameters

2195

---

What is the difference bitween control net scaner and device net scaner

3600

---

Identification of ss fittings, pilot valves, relief valve.

1828

---

what is the importance of CV in the control valves? how it is calculated?

2448

---

how to change measuring units from mmwc to cubm/h in rosemount air flow transmitter with hart communicator fluke 744

2397

---

how to calibrate steam control valve in steam turbine

3332

---

Do you have reference list?

1843

---