My Top Five Tips for Inventor Tube & Pipe
Autodesk Inventor® Tube & Pipe module is my bread and butter. This is the system I use on my job nearly every day. My employer, Powell Fabrication & Manufacturing, Inc., designs and builds skid-mounted chemical processing and mixing equipment for various applications around the globe. In designing this equipment, Tube & Pipe has become our tool of choice. After six years of using this tool nearly every day, I’ve learned a few tips & tricks to getting around in the system. I’d like to share with you what I consider to be my top 5. So, hang on tight and let’s jump right in with Number 5.
#5. Creating a Mixed Units Tube & Pipe Style
Occasionally in using Autodesk Inventor’s Tube & Pipe you may find yourself in a situation where you need to create a design that has more than one system of units in the same pipe run. For example, you may need to design a pipe run that has ANSI Schedule 40 carbon steel piping and instruments, but terminates in a DIN standard flange for customer tie points. Well, there is a way to create these pipe runs using only one Tube & Pipe style. It’s called a Mixed Units style, and here’s what you need to do.
Inventor’s Content Center already contains several examples of DIN flanges that you can use for the example above, though this will work with any combination of specs. Simply locate the flange in your Content Center that is closest to the spec you need, and save a copy of that family to your own Read/Write Content Center library.
This family has a column named ND which contains the sizes of the flanges, in millimeters, expressed as M10, M15, etc. In order to make this family table a Mixed Unit table, edit the Family Table and add two new columns: ND1 and ND2. In the ND1 column simply repeat the contents of the ND column so it has the metric sizes listed as Nominal Diameter 1. In ND2, put the Imperial unit equivalent sizes. Then, saving and applying the changes, right-click the family in the Content Center Editor window and select Family Properties. On the Parameter Mapping tab, set the NominalSize and  so they are mapped to ND1 and ND2, respectively.
Once you apply the changes, this flange is now ready to be used in a Mixed Units style. A Mixed Unit Tube & Pipe Style will require a Mixed Unit Flange and Gasket, so repeat this with as many fittings as needed to create your T&P Styles. Next, create a new Tube & Pipe style. You must be in a Tube & Pipe assembly to be able to do this, or be editing the Tube & Pipe template file named Piping Runs.iam. This file is usually found in your Design Data path in a folder named Tube & Pipe. This file is where you would place any styles that you want to be able to use all of the time. If the style is a one-time-only thing, you can create the style in the assembly where it will be used.
Figure 1: Parameter mapping
To set this to a Mixed Unit style, first you need to designate that it is a Flanged style. When you select Mixed Units, a warning opens to let you know that in order to make a Mixed Unit style you will first need to select a flange fitting that is set up for Mixed Units. Select Yes on this warning box and you will be taken to the fitting selection window.
Figure 2: Selecting Yes moves you to the fitting selection window
Using the filtering tools as needed, locate the Flange fitting that you set to have the dual units. Once that fitting is applied to the style, the style will become a Mixed Unit style, and you can continue to select fittings to finish it out. Remember that this style will also require a gasket that has been set up as Mixed Units. Save your style, and you are ready to start routing pipe in mixed units.
#4. Filling Gaps in Pipe Routes
From time to time, in Tube & Pipe, you may run into a situation that cannot be resolved with a simple route change. This is generally (but not always) when dealing with a lot of “fitting to fitting” connections. That is, connections where there is no pipe spool between groups of fittings. Sometimes when a change becomes necessary and you need to move some of these fittings around, the only way to do it is to break all of the connections on the grouping, and then re-connect them as the situation calls for. The problem with this is that when a route is connected to this grouping of fittings, the route ends up hanging out in the breeze once the fittings have been reassembled. In this example, the valve and flange were moved up to the elbow causing a gap in the route.
Figure 3: Gap in the route
Correcting this would be so easy, if only Tube & Pipe had an “Extend” feature… but alas, it does not. So here is what you need to do: edit the route. Select the “Route” command from the toolbar and pick the bottom of the valve as a starting point; route a short section ending in space above the endpoint of the lower route segment. Do not connect this new route segment to the existing one, as this would cause an “Auto-Route” to be created.
Delete the dimensions from both the new short segment and the existing segment, so neither one is dimensioned or fully constrained. Add a coincident constraint between the two endpoints, joining them. Then window around the joined intersection point of the two segments and delete the point. The two segments will become one, and a driven dimension will appear on the line segment.
When you finish the route, the new segment should populate (assuming the route you are working on has already been populated).
#3. Copy an Existing Pipe Run and Make it Adaptive
So, you’re working in Inventor Tube & Pipe, and you find that you have several pipe runs that are exactly the same. Do you create each one individually and spend a lot of time repeating yourself? You certainly can do that, but there is another choice. As each pipe run is saved as an Inventor assembly, they can easily be inserted into your assembly and placed using standard assembly constraints. In this way you can duplicate a pipe run many times while only having to model it once. But what happens when someone comes along and wants to make a change to just one of these runs? Well, the rest of them will follow the same change, of course. If this is not what you wanted, there is an alternative.
If you place the copied assembly beneath the Master Pipe Run (Tube & Pipe Runs.iam), you can select the copy and choose to make it adaptive. When you select this option, a dialog will open, allowing you to rename each part (not including library parts). Once you have renamed these parts, the pipeline becomes an independent, adaptive, and editable pipe run. In this way you can quickly copy pipe runs that are nearly identical, without having to fully model each one, and still be able to make each one a unique run.
#2. Quick Place Pipe Fittings
When working within a pipe route, it is sometimes necessary to have multiple copies of the same fitting available on the screen. Or sometimes you just want to quickly place one copy of an existing fitting. The temptation here is to use copy and paste functions in order to avoid having to keep going back to the Content Center. Content Center is a great tool, but it can take some time to open and navigate through large libraries to locate a single fitting.
Figure 4: Place Fitting feature
Inside of Tube & Pipe, however, never use copy and paste. Copy and paste can make it difficult, if not impossible, to delete this fitting later if necessary. Best practice is to always use the Tube & Pipe tools to place all of your fittings.
A quick tip to use is the “Place Fitting” command. Normally this command takes you to a file window to navigate to a file outside of the Content Center. But with this little tip, it can be used for placing a Content Center part without the Content Center being opened. The secret is that the fitting has to be somewhere in your assembly already, even in a different sub-assembly. Simply locate the fitting in question, either in your currently active sub-assembly or in the assembly browser. Pick the fitting to preselect it, then pick the Place Fitting command.
Figure 5: Avoid unwanted movement of pipe runs
A copy of the selected fitting will be brought in, with all of the normal piping options available (Place, Connect, Insert). If you use this, and place the new fitting over the top of an existing one, it will replace the existing fitting as long as it is possible for the fitting to work in that location. For example, placing a tee over an elbow will replace the elbow. You may have to toggle the orientation, but again this is quicker than using the Replace Fitting and scrolling through the Content Center.
#1. Grounding Your Tube & Pipe Runs
This is my Number 1 Tube & Pipe Tip, and one of the first things I always share with new users. It can save a lot of time and heartache as your designs grow in size and complexity.
Have you ever spent any amount of time working on a Tube & Pipe assembly with multiple sub-assemblies, getting everything just perfect, only to return to the top level assembly and accidentally clicking and dragging your tube & pipe runs? They move! Freely! They move, and all of your careful, hard work explodes before your very eyes. After thanking your deity of choice for the existence of an Undo button, try this:
When you create your first T&P run in an assembly, Inventor creates a top level sub-assembly called Tube & Pipe Runs, beneath which all of your pipe runs will reside.
As soon as this is created (along with your first run), return to the top level of your assembly. Use mate and align constraints to constrain Tube & Pipe Runs.iam to the top level—origin plane to origin plane using all three origin planes. Then for each individual pipe run sub-assembly you create, constrain that to Tube & Pip Runs.iam—origin plane to origin plane, just like you did to the top level. Do this before you place any fittings or sketch any routes. Now your runs will stay put where you modeled them, as if they were grounded.
Occasionally your design parameters may not allow for this, as you may need more specific constraints on certain pipe runs, but for general piping design this is a good practice to prevent unwanted movement of your pipe runs.
Well, there you have it. My top 5 Inventor Tube & Pipe tips in a nutshell. Hopefully one or two of these will be helpful to you in your piping pursuits. Until next time… enjoy!