About Piping Assemblies
Piping organizes all pipelines, fittings, and equipment for a piping system in assemblies and subassemblies. Piping creates piping assemblies after you create pipelines. All subsequent modeling occurs within the currently active assembly. Piping allows you to do the following:
• Change active assemblies at any time in the piping design process by selecting a pipeline in the Model Tree or Piping System Tree.
• Convert existing piping assemblies created in one piping design mode to the other mode on-the-fly using the User-Driven piping design mode.
Piping subassemblies are created with references to the parent piping assembly. You can modify a piping subassembly in Assembly mode. In this case, the references to the top level piping assembly or other piping subassemblies are external references. When you edit the definition of pipe segments or features with missing external references, the Remove External References dialog box opens. Click OK to continue. The pipe segments and routing features affected by the missing references are frozen and identified by 
in the Model Tree. You can continue to modify the assembly, but you must open the top level assembly in Piping mode to redefine the missing references.
in the Model Tree. You can continue to modify the assembly, but you must open the top level assembly in Piping mode to redefine the missing references. | Pipe segments and routing features that were created prior to the Pro/ENGINEER Wildfire 4.0 release are not frozen. You can modify the pipeline to update it. |