The Properties palette provides 2 options for configuring parallel bends: Concentric and Fixed radius. These options let you specify the type of bend radius for use in a parallel conduit run.
Specifying parallel bends in a conduit run
Concentric
Concentric applies the bend radius only to the baseline conduit. AutoCAD MEP 2023 toolset automatically calculates the correct radius for inside, middle, and outside radius values to ensure that all radius values follow the industry standard values of 16", 24", 32", and 40", for each conduit bend.
Concentric
Fixed Radius
Fixed radius uses the bend radius value specified for all bends in parallel conduit run. Elbows in the conduit run use their predefined radius values and are not adjusted. For fixed radius routing, all the bend radius are 16".
Fixed radius