HGL, EGL and head loss results may not be meaningful for variable density systems

A Warning message in AFT Fathom

The concepts of HGL (Hydraulic Gradeline) and EGL (Energy Gradeline) are only valid for constant density systems. This warning is given when HGL, EGL or head loss results are displayed in the output and the system has variable density. It alerts the user that HGL/EGL and head loss output may not be meaningful. Unless otherwise noted, all other output is valid.

This warning can be hidden by setting all head results to not be shown using Output Control.