Cuts an element (such as a wall or pipe) at a selected point, or removes a segment between 2 points.
When you split a wall, the resulting parts are individual walls that can be worked on independently. When you split an MEP element, such as a pipe, the individual segments are no longer connected.
When you split a pipe, a fitting is added according to the settings in the routing preferences. Revit uses the contents of the Union field. If a Union is not defined, then Revit uses the contents of the Flange field. If both a Union and a Flange are defined, the contents of the Flange field are used. When you split a duct, Revit uses the contents of the Union field. When you split a cable tray or conduit, Revit uses the contents of the Union field in the Type Properties.