How do you control a valve with PID?

Proportional, Integral, Derivative (PID) control is the best method to control the position of a valve based on flow rate feedback. The error between the setpoint and the feedback from an analog device can be fed into a PID function. The output of the PID can then directly control an analog output to a control valve.

What are methods for PID controller tuning?

In broad terms, there are three PID tuning methods for determining the optimal combination of these settings: heuristic tuning, rule-based tuning, and model-based tuning. Each method has its pros and cons.

What is smart positioner in control valve?

Smart valve positioners are digital valve controllers, microprocessor-based, current to pneumatic instruments with internal logic capability. They are designed to convert a current signal to a pressure signal to operate a valve.

What is PID control valve?

A PID controller is an instrument used in industrial control applications to regulate temperature, flow, pressure, speed and other process variables. PID (proportional integral derivative) controllers use a control loop feedback mechanism to control process variables and are the most accurate and stable controller.

How does a PID control work?

PID Controller Working Principle The working principle behind a PID controller is that the proportional, integral and derivative terms must be individually adjusted or “tuned.” Based on the difference between these values a correction factor is calculated and applied to the input.

How do I calibrate my smart positioner?

For the SMART Control Valve, we can use a HART communicator to calibrate the control valve. Give the supply pressure according to the valve as per nameplate details. Connect the HART to the valve positioner. Then go to valve simulate command, enter 0\% and observe the valve position.

How do you calibrate a positioner?

An Overview of Step-by-Step Calibration of Control Valve Positioner

1. The measurable pressure range is shown on the supply gauge.
2. Set the input value to the lowest reading value.
3. Further slowly adjust the nozzle pin to get zero value.
4. Then slowly increase the input pressure value to 3psi, and check if you get zero output.