Difference Between Installed and Inherent Characteristics?


#1

The inherent characteristic is a plot of the flow rate through a valve (or Cv) against percentage opening with a constant pressure drop across the valve.

This is the result of a workshop test where the upstream and downstream pressure are held constant and the only variables are the flow rate and opening of the valve.

The installed characteristic is the plot of flow against opening using actual pressure drops experienced in practice. Due to the fact that in most applications the pressure drop increases as the flow rate drops, the installed characteristic will normally change from =% towards linear, and from linear towards quick opening.


#2

Inherent characteristics could be called as the ideal characteristics a control valve have in which pressure drop is least or kept constant while flow.

But practically there are some difference we find.

Or inherent characteristics could be called the characteristics of control valve checked at manufacturer’s site where everything is tried to keep all certain parameters at no change or constant.