When Angles is selected in the left panel, the right panel displays options for specifying the fitting angle that Revit will use when adding or modifying pipe.
The settings for fitting angles can be copied to another project using the Transfer Project Standards feature.
Select Use any Angle to have Revit use any angle supported by the fitting content.
Select Use Specific Angles to enable or disable the angles that Revit should use when laying out a pipe run.
Note: When manually creating a layout using a limited set of angles, you may notice that the selection point will be respected and the bend angle may be different from the preview.
