Scaling comparison in valves

[AChatwin]

Hello,
I was hoping that someone would be able to advise me on how to compare the "tangible" difference between potential scaling in two valves. They are axial flow valves and both are similar in design. One valve does however produce a higher pressure drop. I am aware that the higher the pressure drop the greater the likley hood of scaling. I just need to somehow quantify the difference between the two valves.

Any advice would be most welcome.

Thanks