How do we define pressure lift and delta_p?

[dlohmeier]

In our branch pit, there is an entry called "PL", which stands for pressure lift. As far as I understand, this is often connected to components that can add a pressure lift independently of the flow model itself. However, when we extract results, we often seem to have to definitions of the term "delta_p_bar": either the pressure lift or the difference between p_to and p_from. We should make sure to always be consistent and not mix the two aspects. But I am not sure how we use these terms in different components. Could someone help me there?