What is an ‘over sized’ control valve? How to solve an oversize problem?


#1

A control valve is said to be over sized when a minimum signal to the valve (minimum opening of the valve) brings the process to the set point rapidly.

This situation leads to an imbalance and high gain in the control loop.

The problem can be solved by changing the valve trim to a reduced trim size or by replacing the control valve to the correct size.