Specifies the multiplier of fluid density (FDM) used in this load case. The fluid density used for an element is this multiplier times the Fluid Density specified for the element.
If you define FDM as zero, the software ignores the Fluid Density for this load case and only uses the Pipe Density and insulation densities, similar to the WNC load type.
This option supports multiple fluid densities in the model. See Multiple Fluid Densities Using the Fluid Density Multiplier.