Efficient Pipe Designs

Efficient Pipe Designs

Efficient Pipe Designs

Efficient Pipe Designs

Speaker:Bryan Thomasy – Tetra Tech Inc.

C14785-VThis class will show you how to manipulate and generate pipe parts lists and networks to efficiently design complex pipe networks using alignments, profiles, intersections, and pipes. You will see a 3-staged approach to design and output for creating a custom pipe fittings library, for generating multiple complex pipe networks and merging them together into one interactive network, and then moving this to constructible plan sets. The class will contain instructions on how to add structure fittings and blocks to the existing pipe catalog in the form of water fittings and then assign styles to those fittings to represent the item graphically. We shall then move on with a basic layout using alignments, then produce a profile of the center of our pipe. From this we will use intersections to tie the branches of our network together and then extract the feature line to create the pipe.

Learning Objectives

At the end of this class, you will be able to:

  • Generate part/structure families
  • Efficiently modify and manipulate the pipe/structure catalogue
  • Create Pipe Network Parts list from the new catalogue
  • Utilize a 3 stage design method
  • Layout your design in an alignment and vertical profile format
  • Use the Civil 3D intersection tool to tie your vertical alignments together
  • Generate your designed pipe network from the alignment and profile
  • Create and Label Plan & Profile sheets with ease.

About the Speaker

I have been an AutoCAD users since 1985. I have 20+ years of civil experience ranging from Commercial / Residential site grading and utility design, to large diameter pipe line and booster station design, to Mining and Dam design. I began using Softdesk, then moved up through Land Desktop, to LDT and now into Civil 3D. I have been using Civil 3D since 2007 in producing constructible documentation. My current position is CAD Manager Civil Designer


Generate part/structure families

Pipe & Structures:

Civil 3D comes out of the box with a variety of structures, but they are primarily geared for gravity systems. For this class we will concentrate on water systems, however all the strategies covered can be applied to various pipe systems. We will copy and modify particular structures to ‘simulate’ that which we need in the field. To do this, I recommend generating a new catalog and parts based on an existing part.

Saving and creating new parts

The purpose is to create a foundation of simplified parametric parts where one can attach horizontal blocks, and it will give something pleasing to look at in 3D. Out of part builder, you will need to copy the Cylindrical and Rectangular Junction Structure NF and saved them as a new Chapter and part.

To do so, open the Part Builder and click on either the Cylindrical or Rectangular Junction Structure NF, then click on the Modify icon, and the drawing will open.

As shown below, click on the copy icon

Civil 3D will prompt you to save the part family. I would recommend creating a new Chapter, then placing the new part within the new chapter. You must give it a unique part name, and the part description will be the description automatically populated by all parts from this new part. So choose it well.

As you can see, I have generated one for basic structures, and because I like my valves to appear round, I created one for the cylindrical structures

Efficiently modify and manipulate the pipe/structure catalogue

Think of these new parts as Legos. You have the basic building blocks. Now we need to modify the parts such that they appear correct in 3D. With the open part drawing, we need to edit the values and add our own

As you hover over the different columns, they will identify what they control. You can also modify the contents, as shown above and here to the right. Research your pipe thicknesses, and this will help you set the structure lengths, wall and floor thicknesses.

I do want to call to your attention the SRS (Rim to Sump Height) and SVPC (Vertical pipe clearance). I have these set to minimums so it will lessen the amount of structure stretching that will need to be done after the structure is inserted. If you forget a size, you can always come back in and add after.

Tip: Make sure the sizes you add are correct. If you find a mistake, you will have to go back into the Parts Lists you generated from these structures and reset the parameters. This can be very time consuming, and your structures will not appear correct in 3D or in profile until they are changed

Creating Pipe Network Parts Lists from the new catalogue

This will be the simplest, yet most time consuming portion of the task. So make sure you have all the parts ready prior to starting this stage. You will need the following:

  • Clearly thought out parts lists for all your pipe fittings
  • Horizontal blocks of your pipe fittings – if you have none, you can check the web for product sizes and such
  • Vertical blocks of your pipe fittings (optional)

I would recommend one diameter for each parts list. This will keep the amount of blocks in your drawing down and not bloat your drawing with un-purgable items. You can add new parts lists to the drawing when you need them.

The goal is to create a structure part and style for every fitting needed, as seen below.

As you can see, the structure is added based on the diameter of the pipe, then the style is refined to incorporate the horizontal block desired to be displayed. These blocks came from our Process library. This is why the size option is set to fixed scale and that scale is 0.0833333333 (1/12).

The model tab is set to use the catalog defined 3D part. The Profile tab is set to display as boundary, as is the section tab. These can be modified to display a block if needed.

Tip: within the blocks used for Plan, Profile, and Section viewing, make sure to ‘Enable part masking’. Also, make the insertion point of the block at the intersection of the connecting pipes. This will aid in the covering of the pipes under the blocks. In areas where the pipe is exposed, use wipeouts within the block to hid the pipes not covered by the part.

Rules for structures and pipe:

I have the honor of being friends with this year’s AUGI top DAUG, Brian Hailey. He has a fantastic method for existing pipe creation for pressure pipes over existing topography. His method is out on YouTube and you can find it here:

I used his method in this section for rules to help with structure cleanup. The method is simple. Create a general pipe rule which can be applied to all pipes regardless of diameter.

For the Structure rules, one needs to be created for each pipe diameter to allow for the sump depth to be correctly entered. You also want to control the pipe drop across the structure. This rule must be added also.


Proper structures with correct sizes must be created. Then fitting blocks will be used within the styles to simulate the desired look in each of the different plan, profile, and section views. Once started, you can assume about 2 hours per parts list for development if you already have the necessary block. Setup rules for the appropriate sizes in structures and pipes

Utilize a 3 stage design method

The Theory:

Now that we have the hard part out of the way, let’s start getting pipes in the ground. As discussed before, there are multiple variations of the use for pressure pipes

  • Residential \ Commercial
  • Process Yard piping
  • Large Diameter linear main lines

We shall attempt to explore one of these within this section and learn how to best handle it with some simple “checks-n-balance” type questions. I am certain that the above does not encompass all forms of pressure piping, but the items we cover should be sufficient to help you if special circumstances are to arise.

Design Method:

Typically we use a three stage approach, mainly divided by milestones within the project

30% Milestone - This is when the site has been defined, topography and surface has been gathered and the designer/engineer/PM has had a chance to look over the area and decide where the utilities should be located. Questions of; level of detail, drawing scale, critical tie and obstructions need to be asked.

60% Milestone - Where profiles are generated from the alignments and the vertical layout are taking shape. This is where the level of detail is determined in clearance, existing/proposed pipe crossings, ditches, channels, and other items are defined. In all cases, a vertical profile representing the pipe is laid out in the profile view

90% Milestone - This is when you hit a no-stop point in the project and begin to place your vertical and alignments in as pipe. Up until this point it has all been alignments and vertical profiles.

These basic milestones can be applied to practically any project regardless of size or phase.

Basic principles:

In most cases for pipeline design, you will need the following items within your model;

  • Surface
  • Alignment
  • Profile
  • Existing Utilities (if any)

For our exercise we shall be designing a Linear Main Force line.

Layout your design in an alignment and vertical profile format

The Linear Main Force lines are the bases for all other forms. This is basically a pipe that runs from point A to point B, and avoids all interferences and typically runs under exiting ground.

At this time, should have your existing topo, existing features, and any proposed features. From here we will create a drawing from our standard template and import in various styles as we need them.

30% Milestone - Pipe Alignment Layout:

When laying out the pipeline, you want to start off on the right foot by only using angles of the fittings that are available. To do this you can modify your ‘Polar Tracking’ and set it such as shown here. This way as you are drawing the polyline that will be come your alignment, it will only use the correct angles. Notice that I have only the primary bends and not ones which are combinations of 2 or more.

Once you have the alignment laid out, you can convert it into an alignment using the tools in Civil 3D. From there you can sample the surface(s) you wish and generate a Profile View. As shown here.

Above we see the primary 24” Main, and an 8” supply line that tees off. An alignment and profile has been generated for both. This is when you can look at the vertical information and see potential issues such as ditches, utility clashes and other issues that may redirect the alignments. Once the layout is agreed upon, we can move forward to the 60% milestone.

60% Milestone – Vertical Pipeline Layout:

We are now going to assign a vertical design to the horizontal alignment. Using the ‘Profile Creation’ tool within Civil 3D, we will create a vertical profile that follows the existing grade which will represent the top of our pipe.

Once this is accomplished we will use the ‘Raise/Lower’ tool to move the vertical alignment down to the desired depth. This will give us our starting point.

We can now analyses the slopes, depths, interferences, and tie points. In the example project, our vertical alignment passes through a culvert and under a pond. It will be important to allow for adequate separation. To accomplish this in a timely fashion, we will use two tools.

Pipe crossing dynamic block

  • The block is lines that can change to fit the vertical exaggeration of the profile view, and can only stretch in one linear direction. This block is based off the standard pipe crossing method of a series of 45 degree angles and a standard 20 foot length of pipe below the intersection.

Vertical Deflection labeling style

  • The style is a profile label style for grade breaks that uses an expression to return the deflection angle when passing through a PI

These two tools greatly aid in the vertical layout by adding pi points along the pipe crossing block, and sliding the alignment using the grips to achieve the desired deflections.

Note: If your pipe run changes diameter within the same horizontal alignment, make sure and create a vertical alignment for each pipe diameter. This will help down the road when we convert the vertical alignment into pipes.

Intersection tool:

Within Civil 3D, there is a tool for corridors which aid in intersections. This is an untapped resource which we will use in our pipe layouts. In our example project, we have a main line and an 8” supply line which connect to the main. We need to have the ability to tie the vertical alignment of the 8” line to that of the 24” line in the event the 24” main line ever moves vertically. This can be done with the use of the ‘Intersection’ tool.

After the vertical alignment for the main line has been established, we need to create one for the 8” supply line. Once this is completed, we will use the intersection tool and connect them together.

This tool will ask you to select the intersection of the two alignments, and then walk you through the wizard. In the second dialog box, you want to make sure and unselect the ‘Create or specify offset alignment’, we only want to use this tool for attaching the verticals together.

In the second dialog box, you will also notice the Intersection ‘Priority’ box showing which alignment will have priority over the other.

If the alignments crossed, then you would be asked to identify the primary. In this example, the 8” supply line ‘tees’ into the main and thus the 24” main is automatically selected as the primary.

Once completed, your intersection will appear as shown below. You will have the ability to move the alignment around, however they must remain in contact with each other, once the contact is broken, the link is broken. It can be rebuilt easily.
This has now tied the vertical of the 8” supply line to the vertical of the 24” Main. This can be seen in the vertical profile view.

As seen here, I have selected the vertical of the 8” supply line, and when it highlights with its grips, the beginning has a ‘Lock’ looking grip. Indicating it is locked and cannot be edited manually.

If I were to raise or lower the 24” main vertical, the 8” would automatically readjust. This can also be accomplished through a data reference. In this case if we were to data reference in the 24” main, we could still tie the 8” supply line to it with no trouble.

In addition, even if the 8” supply line were to cross the 24” main multiple times, an intersection link could be established at every intersection.


We created an alignment, generated a profile from it, then using multiple tools, created a vertical alignment to represent the depth of our pipe. The tools allow any branches or ties to the main alignment to be tied and to move with it. So if any changes need to be made, all items will update.
Generate your designed pipe network from the alignment and profile

90% Milestone – Create Pipe

Now that the vertical has been created, and all design issues have been addressed, we can continue to create the pipe.

Pipe Creation:

At this point, we are going to extract the horizontal and vertical alignment information out to a single feature line. From the feature line, we will convert it into our pipe and then modify the various fittings and then bring it into the profile to make sure it works properly.

The first thing we must do is to adjust the vertical alignment such that it represents the CENTER of our pipe. So if your pipe is 8” in diameter, you need to select the vertical alignment and lower it 4”.

Extracting the Feature line:

In the drawing that has the horizontal and vertical alignment, go to your ‘Home’ ribbon and pull-down the ‘Feature Line’ button and select the ‘Create Feature lines from alignment’. Select the horizontal alignment in the drawing.

A dialog box will appear.