NX Routing Mechanical Notes

October 8, 2015




NX Routing Mechanical Notes – Part 1


This article will highlight some notable aspects of Siemens’ Routing Mechanical application.

I ran across these aspects while putting together class materials for a 1-day course that we offer at Swoosh. Think of this as a form of Cliff Notes for the application.

Routing Mechanical equips the user with a suite of tools that can generate a 3D representation of pneumatic or hydraulic piping or tubing assemblies. This package emulates industry practices with very specific detail design and fabrication techniques. While creating realistic models that help the designer conceptualize their intended product, NX Routing Mechanical also accomplishes many automated tasks necessary for the specification, problem solving, and documentation of these designs.

Things worth knowing about the application:

For the most part, Routing Mechanical now uses the Reuse Library instead of a Specify Item dialog and the library now contains hundreds of standard and not-so-standard parts such as valves, gaskets, reducers, ring joints, insulation, etc. Some functions still use the Specify Item dialog, however, which is really just a File->Open command.

reuse library

Generally the first step in building a routing assembly is to generate paths and then add stock and qualified parts to them.

Like much of the NX software, the default units in the package is metric and there seems to be a bit more items in the library for metric assemblies, probably because in the early days of routing, metric was the only game. To change over from one unit system to the other, a variable in the configuration file should be commented out and the other uncommented. (See ugii_env_ug.dat to switch libraries.)

default units

There are many commands unique to routing that should be used instead of the nearly equivalent assemblies command.

Unique Commands

Use the Routing command “Place Part” to add parts to a routing assembly rather than the Assemblies Add Component. That way, you can utilize its ports or anchor to position it in the routing assembly.

Use Replace Part in a routing assembly rather than Assemblies→Components→Replace Component. Replace Part maintains connections and invokes design rule checking, whereas Replace Component does not.

Likewise, use Move Part (Routing) as opposed to the Move Component (Assemblies) command to move or reposition a qualified part. Move Part allows you to utilize the routing ports of the qualified part, whereas the Move command does not.

Avoid using Edit→Delete to remove parts as this results in the routing segment remaining subdivided where the part was formerly. Instead, use the routing command, Remove Part.

Run Navigator

A Run Navigator offers a listing of manually defined “Runs” which are, in essence, a fabricatable (that’s right… FABRICATABLE!), manageable subassembly of the end product. It appears immediately upon selecting the application.

run navigator
Routing Control Point

One of the unique routing objects that serves a very big role in the accomplishment of a routing assembly is the Routing Control Point, or RCP. An RCP is basically a connection point where path segments join with other segments, parts, or just end. They are “intelligent” in that they can control the location and orientation of adjoining paths and parts and they make it very simple to add, or “place” parts into the assembly.

Assign Corner

One command that depends on the selection of an RCP is Assign Corner. This accommodates the editing and managing of the routing at that location for the purposes of adding a bend or editing. To edit, MB3 on the RCP.

assign corner
Qualified Parts

Another very important object in a routing assembly is a Port. Generally, all of the parts, devices, fittings, connectors, etc. need to have one or more Ports assigned. Qualified parts include these Port positions and optional anchor and orientation definitions. This gives you the ability to automatically get positioning and orientation options when placing a qualified part into an assembly with a simple click of a Placement Solution button.

placement solutions

Also, if you are routing in a subassembly and you want to use Ports of a part that are in a higher level in the assembly, they can be WAVE linked into the subassembly.


Speaking of qualifying parts, entire Part Families and entire assemblies can be qualified. In fact, much of the content of the Reuse Library is all Part Family template files. This gives you very effective ways to search and filter for the actual part you want to use. A handy MB3 popup on the Reuse Family folders, “Search Children” brings up a really cool dialog for that.

routing part library

The Routing Preferences specify the current Discipline. A Discipline determines which parts and stock are available to you from the Routing Part Library. Each Routing application can have more than one discipline; for instance in mechanical, you can choose between piping, tubing, or HVAC. You can also switch from one discipline to another at any time within a single part or session.

routing preferences
material options

Selecting appropriately matched parts for placement into an existing routing can be easily and accurately achieved by choosing Information->Routing->Routing Objects. Select a Port, choose OK, and scroll to the bottom of the Information window:

port characteristics

Based on the characteristics of this port, you need to place NPS 200 flanges on this pipe run.

Legacy Mode

By default, all stock and overstock is created in Legacy mode. That is, it is created as swept features in the work part. The Convert to stock as components command converts stock features in the routing to component objects of the assembly. This will be a standard that should be decided upon and instituted at the corporate level. Individual users shouldn’t make the decision to use this mode or not.


Well that’s what I found in a week or so. If you have a need to define contained systems that move or process fluids, gases, or other substances, you might consider taking a close look at NX Routing Mechanical to accommodate the designs and stop using the old traditional paper-based methods. This approach is extremely conducive to your CAD environment.

Post by Garrett Koch

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