The size description Undefined or Duplicate is temporary. The size description is set from the nominal dimensions.
You can now modify piping component dimensions for each size.
You can position the mouse over a parameter to display tooltips. Parameters can be display options (for example: Number of segments, Shape of an end cap).
Some parameters can be set to calculate from other parameters. For example: an elbow bend radius (R) value of zero indicates the bend is set to half the diameter (D / 2.0).
For Pipe, set the Nominal Diameter and Size Parameter D: to the same value.