Hi
Can any specialist help me to find how choosing wrong trim in control valves will lead to failure?
For example Equal percentage trim instead of Linear ...
Is there any related article?
thanks

 

Lots of authors, lots of articles out there, but I can't recall one that focuses on having the wrong valve characterization curve. But someone might pop up with a link.

I have seen a couple cases that needed to change to equal percentage to prevent a linear characterized valve from hunting because it tended to overshoot and was constantly hunting for the 'sweet spot'. The valve body size was oversized to account for 'allowance for future expansion'.

A valve body creates drop, too, the smaller the body the greater the drop. An oversized valve in general forces the trim to take the needed pressure drop that its oversized body is not taking.