How to Increase Control Valve Response

http://www.topcontrol.com/fichiers/en/controlvalveperformance.pdf

Changing the valve trim or changing the actuator (say from electric to pneumatic) can alter a valve's response. Sometimes the actuator's response is limited by settings in the positioner, so changing the settings in the positioner can provide faster actuator response and hence valve response.

If the question was really, how to increase the process response, then loop tuning is the first place to look.

Two options:

1. Slug the signal with a low-pass filter.
2. Introduce transmission delay.

Either will introduce instability into the control loop, which will therefore require re-tuning.

First, do you want to increase the response time, or decrease the response time?