Greeting Simon,
Have you found any solution? I am having a similar problem to yours trying to model gas flow network with globe valves.
Only solution I can think of is generating a custom block with corresponding valve characteristics. However, it does not seem possible as other valves are created based on ISO 6358 standarts. In order to get valid information, we need to purchase those standarts. Although, as those standarts are not available free, source code for beforementioned valves are not available in Matlab.
